Light-emitting substrate and preparation method therefor, and display device

Abstract

The present disclosure provides a light-emitting substrate and a preparation method therefor, and a display device. The light-emitting substrate comprises at least one sub-pixel region (100); the sub-pixel region (100) comprises a driving backplane (101) and at least two light-emitting devices provided on the driving backplane (101); the at least two light-emitting devices each comprise a light-emitting layer; the light-emitting layers of the at least two light-emitting devices are sequentially arranged in the thickness direction of the driving backplane (101); the orthographic projections of the light-emitting layers of the at least two light-emitting devices on the driving backplane (101) overlap each other; and in adjacent light-emitting layers, the area of the orthographic projection of the light-emitting layer close to the driving backplane (101) on the driving backplane (101) is less than or equal to the area of the orthographic projection of the light-emitting layer distant from the driving backplane (101) on the driving backplane (101).

Description

Light-emitting substrate, preparation method thereof and display device TECHNICAL FIELD

[0001] The present disclosure relates to, but is not limited to, the technical field of display, in particular to a light-emitting substrate, a preparation method thereof and a display device. BACKGROUND

[0002] The manufacturing size of a light-emitting diode (LED) has a trend of miniaturization, for example, a micro light-emitting diode (Micro LED) or a mini light-emitting diode (Mini LED), which is increasingly concerned due to its small size, low power consumption, long product life and other advantages.

[0003] The light-emitting substrate can display images by using light-emitting diodes, and a plurality of light-emitting diodes emitting different colors are arranged side by side to realize color display. However, the light-emitting substrate of this structure has a small light-emitting area, which affects the display effect of the light-emitting substrate.

[0004] SUMMARY

[0005] The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

[0006] In one aspect, the present disclosure provides a light-emitting substrate, comprising at least one sub-pixel region, the sub-pixel region comprising a driving backplane and at least two light-emitting devices disposed on the driving backplane, the at least two light-emitting devices each comprising a light-emitting layer, the light-emitting layers of the at least two light-emitting devices being sequentially arranged along a thickness direction of the driving backplane, the orthographic projections of the light-emitting layers of the at least two light-emitting devices on the driving backplane overlap, and the area of the orthographic projection of the light-emitting layer closer to the driving backplane in adjacent light-emitting layers on the driving backplane is less than or equal to the area of the orthographic projection of the light-emitting layer farther from the driving backplane in adjacent light-emitting layers on the driving backplane.

[0007] In an exemplary embodiment, the first light-emitting layer, the second light-emitting layer and the third light-emitting layer are sequentially arranged along a direction away from the driving backplane, the orthographic projections of the first light-emitting layer, the second light-emitting layer and the third light-emitting layer on the driving backplane overlap, the area of the orthographic projection of the first light-emitting layer on the driving backplane is less than or equal to the area of the orthographic projection of the second light-emitting layer on the driving backplane, and the area of the orthographic projection of the second light-emitting layer on the driving backplane is less than or equal to the area of the orthographic projection of the third light-emitting layer on the driving backplane.

[0008] In an example embodiment, the orthographic projection of the first light-emitting layer on the driving backplane is in the orthographic projection of the second light-emitting layer on the driving backplane, and the orthographic projection of the second light-emitting layer on the driving backplane is in the orthographic projection of the third light-emitting layer on the driving backplane.

[0009] In an example embodiment, the area of the orthographic projection of the first light-emitting layer on the driving backplane is 10%-50% of the area of the sub-pixel region, the area of the orthographic projection of the second light-emitting layer on the driving backplane is 30%-80% of the area of the sub-pixel region, and the area of the orthographic projection of the third light-emitting layer on the driving backplane is 50%-90% of the area of the sub-pixel region.

[0010] In an example embodiment, the first light-emitting layer is configured to emit blue light, the second light-emitting layer is configured to emit green light, and the third light-emitting layer is configured to emit red light.

[0011] In an example embodiment, the driving backplane comprises an anode driving electrode, and the light-emitting device further comprises an anode, a first end of the anode being connected to the light-emitting layer, and a second end of the anode being connected to the anode driving electrode.

[0012] In an example embodiment, the driving backplane comprises at least two anode driving electrodes, the light-emitting layers of adjacent light-emitting devices are insulated from each other, and the anodes of the adjacent light-emitting devices are connected to the at least two anode driving electrodes correspondingly.

[0013] In an example embodiment, the light-emitting layers of adjacent light-emitting devices are connected in series to form a light-emitting layer series connection group, the light-emitting layer series connection group shares an anode, and the light-emitting layer on the side of the light-emitting layer series connection group close to the driving backplane is connected to the anode driving electrode through the shared anode.

[0014] In an example embodiment, the driving backplane comprises a cathode driving electrode, the light-emitting device further comprises a conductive layer, the conductive layer is arranged on the side of the light-emitting layer away from the driving backplane, at least part of the conductive layer is in direct contact with the light-emitting layer, and the light-emitting device further comprises a cathode, the conductive layer is connected to the cathode driving electrode through the cathode.

[0015] In an example embodiment, the conductive layers of the at least two light-emitting devices share a cathode.

[0016] In an example embodiment, the adjacent light-emitting layers are connected in series through the conductive layer to form a light-emitting layer series connection group, the light-emitting layer series connection group shares a cathode, and the conductive layer on the side of the light-emitting layer series connection group away from the driving backplane is connected to the cathode driving electrode through the shared cathode.

[0017] In an exemplary embodiment, an inorganic medium layer is further included, which is in direct contact with the conductive layer on the side close to the driving backplate and in direct contact with the light-emitting layer on the side away from the driving backplate.

[0018] In an exemplary embodiment, the cathode driving electrode is located in the sub-pixel region, or the light-emitting substrate further includes a non-sub-pixel region on at least one side of the sub-pixel region, and the cathode driving electrode is located in the non-sub-pixel region.

[0019] In an exemplary embodiment, the cathode driving electrode is annular, at least part of the cathode driving electrode is arranged around the periphery of the cathode and is in direct contact with the side wall of the cathode.

[0020] In another aspect, the present disclosure further provides a display device comprising the aforementioned light-emitting substrate.

[0021] In yet another aspect, the present disclosure further provides a preparation method of a light-emitting substrate, comprising:

[0022] At least two light-emitting layers are sequentially arranged on the driving backplate, the at least two light-emitting layers are sequentially arranged along the thickness direction of the driving backplate, the orthographic projections of the at least two light-emitting layers on the driving backplate overlap, and the area of the orthographic projection of the light-emitting layer close to the driving backplate in the adjacent light-emitting layers on the driving backplate is less than or equal to the area of the orthographic projection of the light-emitting layer away from the driving backplate in the adjacent light-emitting layers on the driving backplate.

[0023] Other aspects can become apparent from a review of the drawings and detailed description. BRIEF DESCRIPTION OF DRAWINGS

[0024] The accompanying drawings are included to provide a further understanding of the technical scheme of the present application, and constitute a part of the specification, and are used together with the embodiments of the present application to explain the technical scheme of the present application, and do not constitute a limitation on the technical scheme of the present application.

[0025] FIG. 1 is a schematic diagram of the cross-sectional structure of a light-emitting substrate according to an exemplary embodiment of the present disclosure;

[0026] FIG. 2a is a schematic diagram of the light-emitting substrate after forming the first anode driving electrode, the second anode driving electrode, the third anode driving electrode, and the cathode driving electrode in the preparation process of the light-emitting substrate according to an exemplary embodiment of the present disclosure;

[0027] FIG. 2b is a schematic diagram of the light-emitting substrate after forming the first light-emitting film in the preparation process of the light-emitting substrate according to an exemplary embodiment of the present disclosure;

[0028] FIG. 2c is a schematic diagram of the light-emitting substrate after forming the first light-emitting layer in the preparation process of the light-emitting substrate according to an exemplary embodiment of the present disclosure;

[0029] FIG. 2d is a schematic view of a light emitting substrate after forming a first inorganic medium layer in the preparation process of an exemplary embodiment of the present disclosure;

[0030] FIG. 2e is a schematic view of a light emitting substrate after forming a first conductive layer in the preparation process of an exemplary embodiment of the present disclosure;

[0031] FIG. 2f is a schematic view of a light emitting substrate after forming a second inorganic medium layer in the preparation process of an exemplary embodiment of the present disclosure;

[0032] FIG. 2g is a schematic view of a light emitting substrate after forming a second light emitting layer and a third inorganic medium layer in the preparation process of an exemplary embodiment of the present disclosure;

[0033] FIG. 2h is a schematic view of a light emitting substrate after forming a second conductive layer in the preparation process of an exemplary embodiment of the present disclosure;

[0034] FIG. 2i is a schematic view of a light emitting substrate after forming a fourth inorganic medium layer in the preparation process of an exemplary embodiment of the present disclosure;

[0035] FIG. 2j is a schematic view of a light emitting substrate after forming a third light emitting layer and a fifth inorganic medium layer in the preparation process of an exemplary embodiment of the present disclosure;

[0036] FIG. 2k is a schematic view of a light emitting substrate after forming a third conductive layer in the preparation process of an exemplary embodiment of the present disclosure;

[0037] FIG. 3 is a schematic view of a cross-sectional structure of another light emitting substrate in an exemplary embodiment of the present disclosure;

[0038] FIG. 4 is a schematic view of a cross-sectional structure of another light emitting substrate in an exemplary embodiment of the present disclosure;

[0039] FIG. 5 is a schematic view of a cross-sectional structure of another light emitting substrate in an exemplary embodiment of the present disclosure. DETAILED DESCRIPTION

[0040] In order to make the objectives, technical solutions and advantages of the present disclosure clearer, below will be a detailed description of the embodiments of the present disclosure in conjunction with the drawings. Note that the embodiments can be implemented in multiple different forms. One of ordinary skill in the art can easily understand that the manners and contents can be changed into various forms without departing from the spirit and scope of the present disclosure. Therefore, the present disclosure should not be interpreted as being limited to the contents described in the following embodiments. The embodiments in the present disclosure and the features in the embodiments can be combined with each other arbitrarily without conflict.

[0041] In the drawings, the size, the thickness, or the region of each component is sometimes exaggerated, and sometimes shrunk for clarity. Therefore, one embodiment of the present disclosure is not necessarily limited to such a scale. The drawings are schematic views showing ideal examples, and the present disclosure is not limited to shapes or values shown in the drawings.

[0042] In the present specification, ordinal terms, such as "first", "second", and "third", are used for the purpose of avoiding confusion with the components and are not used to limit the number thereof in terms of quantity.

[0043] In the present specification, terms of direction or position relationship, such as "middle", "upper", "lower", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, which are used for the purpose of explaining the positional relationship of components with reference to the drawings, are used only for the purpose of facilitating the description of the present specification and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be construed as limiting the present disclosure. The positional relationship of the components is appropriately changed according to the direction in which each component is described. Therefore, it is not limited to the terms described in the specification, and can be appropriately changed depending on the situation.

[0044] In the present specification, unless explicitly specified and limited otherwise, the terms "mount", "connected", and "linked" are to be interpreted broadly. For example, it can be fixed connection, or detachable connection, or integral connection; can be mechanical connection, or electrical connection; can be direct connection, or indirect connection via an intermediate part, or communication inside two elements. The specific meaning of the above terms in the present disclosure can be understood by those skilled in the art according to the specific situation.

[0045] In the present specification, a transistor refers to an element including at least a gate electrode, a drain electrode, and a source electrode. The transistor has a channel region between the drain electrode (a drain electrode terminal, a drain region, or a drain electrode) and the source electrode (a source electrode terminal, a source region, or a source electrode), and current can flow through the drain electrode, the channel region, and the source electrode. Note that in the present specification, the channel region refers to a region where current mainly flows.

[0046] In the present specification, the first electrode can be a drain electrode and the second electrode can be a source electrode, or the first electrode can be a source electrode and the second electrode can be a drain electrode. In the case of using a transistor with opposite polarity or in the case of changing the direction of current in circuit operation, the functions of "source electrode" and "drain electrode" are sometimes interchanged. Therefore, in the present specification, "source electrode" and "drain electrode" can be interchanged.

[0047] In this specification, "electrically connected" includes the case where elements are connected through an element having some electrical action. The element having some electrical action is not particularly limited as long as it can transmit and receive an electrical signal between the elements to be connected. Examples of the element having some electrical action include not only an electrode and a wiring but also a switching element such as a transistor, a resistor, an inductor, a capacitor, and another element having some function.

[0048] In this specification, "parallel" means a state where an angle formed by two straight lines is greater than or equal to -10° and less than or equal to 10°, and thus a state where the angle is greater than or equal to -5° and less than or equal to 5° is also included. In addition, "perpendicular" means a state where an angle formed by two straight lines is greater than or equal to 80° and less than or equal to 100°, and thus a state where the angle is greater than or equal to 85° and less than or equal to 95° is also included.

[0049] In this specification, "film" and "layer" can be interchanged with each other. For example, "a conductive layer" can be replaced with "a conductive film". Similarly, "an insulating film" can be replaced with "an insulating layer".

[0050] In the present disclosure, "about" means not strictly limited to a boundary, allowing a range of values within process and measurement errors.

[0051] An exemplary embodiment of the present disclosure provides a light-emitting substrate, comprising at least one sub-pixel region, the sub-pixel region comprising a driving backplane and at least two light-emitting devices disposed on the driving backplane, the at least two light-emitting devices each comprising a light-emitting layer, the light-emitting layers of the at least two light-emitting devices being disposed in sequence along a thickness direction of the driving backplane, and a projection of the light-emitting layers of the at least two light-emitting devices on the driving backplane being overlapped, an area of a projection of a light-emitting layer closer to the driving backplane in adjacent light-emitting layers on the driving backplane being less than or equal to an area of a projection of a light-emitting layer farther from the driving backplane in the adjacent light-emitting layers on the driving backplane.

[0052] The scheme of the present embodiment is exemplified below by some examples.

[0053] FIG. 1 is a schematic diagram of a cross-sectional structure of a light-emitting substrate according to an example embodiment of the present disclosure. In an example embodiment, as shown in FIG. 1, in a direction perpendicular to the light-emitting substrate, the light-emitting substrate according to the example embodiment of the present disclosure includes a sub-pixel region 100, which includes a driving backplane 101, an insulating layer 10 disposed on the driving backplane 101, a first light-emitting layer 31 and a first inorganic medium layer 11 disposed on a side of the insulating layer 10 away from the driving backplane 101, a first conductive layer 41 disposed on a side of the first light-emitting layer 31 and the first inorganic medium layer 11 away from the driving backplane 101, a second inorganic medium layer 12 disposed on a side of the first conductive layer 41 away from the driving backplane 101, a second light-emitting layer 32 and a third inorganic medium layer 13 disposed on a side of the second inorganic medium layer 12 away from the driving backplane 101, a second conductive layer 42 disposed on a side of the second light-emitting layer 32 and the third inorganic medium layer 13 away from the driving backplane 101, a fourth inorganic medium layer 14 disposed on a side of the second conductive layer 42 away from the driving backplane 101, a third light-emitting layer 33 and a fifth inorganic medium layer 15 disposed on a side of the fourth inorganic medium layer 14 away from the driving backplane 101, and a third conductive layer 43 disposed on a side of the third light-emitting layer 33 and the fifth inorganic medium layer 15 away from the driving backplane 101. The first light-emitting layer 31 is provided with a first anode 51 on a side close to the driving backplane 101, the second light-emitting layer 32 is provided with a second anode 52 on a side close to the driving backplane 101, and the third light-emitting layer 33 is provided with a third anode 53 on a side close to the driving backplane 101. The first conductive layer 41, the second conductive layer 42, and the third conductive layer 43 share a cathode 60.

[0054] In an example embodiment, the driving backplane 101 includes a substrate and a first anode driving electrode 21, a second anode driving electrode 22, a third anode driving electrode 23, and a cathode driving electrode 24 disposed on the substrate. The first anode driving electrode 21 is electrically connected to the first anode 51 and is configured to provide an anode driving signal to the first anode 51. The second anode driving electrode 22 is electrically connected to the second anode 52 and is configured to provide an anode driving signal to the second anode 52. The third anode driving electrode 23 is electrically connected to the third anode 53 and is configured to provide an anode driving signal to the third anode 53. The cathode driving electrode 24 is electrically connected to the cathode 60 and is configured to provide a cathode driving signal to the cathode 60.

[0055] In an example embodiment, the first anode driving electrode 21, the second anode driving electrode 22, the third anode driving electrode 23, and the cathode driving electrode 24 are all located in the sub-pixel region 100.

[0056] In the example embodiment, the first light-emitting layer 31 is disposed on the insulating layer 10, the first light-emitting layer 31 is disposed in the same layer as the first inorganic medium layer 11, and the orthographic projection of the first light-emitting layer 31 on the driving backplate 101 does not overlap, the orthographic projection of the first light-emitting layer 31 on the driving backplate 101 does not overlap with the orthographic projection of the second anode driving electrode 22, the third anode driving electrode 23, and the cathode driving electrode 24 on the driving backplate 101, the orthographic projection of the first light-emitting layer 31 on the driving backplate 101 covers the orthographic projection of the first anode driving electrode 21 on the driving backplate 101, the first light-emitting layer 31 is connected to the first anode driving electrode 21 through the first anode 51, and the first light-emitting layer 31 is configured to emit blue light.

[0057] In the example embodiment, the area of the orthographic projection of the first light-emitting layer 31 on the driving backplate 101 is 10%-50% of the area of the sub-pixel region 100, for example, the area of the orthographic projection of the first light-emitting layer 31 on the driving backplate 101 is 30%-50% of the area of the sub-pixel region 100.

[0058] In the example embodiment, the area of the orthographic projection of the first light-emitting layer 31 on the driving backplate 101 is 10%-50% of the area of the sub-pixel region 100, for example, the area of the orthographic projection of the first light-emitting layer 31 on the driving backplate 101 is 30%-50% of the area of the sub-pixel region 100.

[0059] In the example embodiment, the first anode 51 extends along a direction perpendicular to the driving backplate 101. The orthographic projection of the first anode 51 on the driving backplate 101 is located in the orthographic projection of the first light-emitting layer 31 on the driving backplate 101. The light-emitting substrate further comprises a first via extending along a direction perpendicular to the driving backplate 101, the first via is formed by a surface of the insulating layer 10 away from the driving backplate 101, penetrates the insulating layer 10, and exposes the first anode driving electrode 21, a first end of the first anode 51 is connected to the first light-emitting layer 31, a second end of the first anode 51 extends along a direction close to the driving backplate 101, and is connected to the first anode driving electrode 21 through the first via.

[0060] In the example embodiment, the first conductive layer 41 is disposed on the side of the first light-emitting layer 31 away from the driving backplate 101, at least part of the first conductive layer 41 overlaps with the orthographic projection of the first light-emitting layer 31 on the driving backplate 101 and directly contacts, for example, the orthographic projection of the first conductive layer 41 on the driving backplate 101 covers the orthographic projection of the first light-emitting layer 31 on the driving backplate 101. The first conductive layer 41 comprises a first region and a second region, the first region completely overlaps with the orthographic projection of the first light-emitting layer 31 on the driving backplate 101 and directly contacts the surface of the first light-emitting layer 31 away from the driving backplate 101; the second region does not overlap with the orthographic projection of the first light-emitting layer 31 on the driving backplate 101, and the second region directly contacts the surface of the first inorganic medium layer 11 away from the driving backplate 101.

[0061] In an exemplary embodiment, the first light-emitting layer 31 has a visible light transmittance of greater than or equal to 80%. For example, the first light-emitting layer 31 has a visible light transmittance of greater than or equal to 90%.

[0062] In an exemplary embodiment, the first conductive layer 41 has a visible light transmittance of greater than or equal to 80%. For example, the first conductive layer 41 has a visible light transmittance of greater than or equal to 90%.

[0063] In an exemplary embodiment, the second light-emitting layer 32 is disposed on the second inorganic medium layer 12, the second light-emitting layer 32 does not overlap with the third inorganic medium layer 13 in the orthographic projection on the driving backboard 101, the second light-emitting layer 32 does not overlap with the third anode driving electrode 23 and the cathode driving electrode 24 in the orthographic projection on the driving backboard 101, and the orthographic projection of the second light-emitting layer 32 on the driving backboard 101 covers the orthographic projection of the first anode driving electrode 21 and the second anode driving electrode 22 on the driving backboard 101; the second light-emitting layer 32 is connected with the second anode driving electrode 22 through the second anode 52, and the second light-emitting layer 32 is configured to emit green light.

[0064] In an exemplary embodiment, the second light-emitting layer 32 overlaps with the first light-emitting layer 31 in the orthographic projection on the driving backboard 101. For example, the orthographic projection of the second light-emitting layer 32 on the driving backboard 101 covers the orthographic projection of the first light-emitting layer 31 on the driving backboard 101. The second light-emitting layer 32 overlaps with the second conductive layer 42 in the orthographic projection on the driving backboard 101.

[0065] In an exemplary embodiment, the area of the orthographic projection of the second light-emitting layer 32 on the driving backboard 101 is 30%-80% of the area of the sub-pixel region 100. For example, the area of the orthographic projection of the second light-emitting layer 32 on the driving backboard 101 is 50%-80% of the area of the sub-pixel region 100.

[0066] The light-emitting substrate according to the embodiments of the present disclosure improves the light-emitting efficiency of the second light-emitting layer by setting the area of the second light-emitting layer to be 30%-80% of the area of the sub-pixel region 100.

[0067] In an example embodiment, the second anode 52 extends along a direction perpendicular to the driving backplane 101. A projection of the second anode 52 on the driving backplane 101 is located in a projection of the second light-emitting layer 32 on the driving backplane 101. The light-emitting substrate further comprises a second via extending along a direction perpendicular to the driving backplane 101, the second via is formed by a surface of the second inorganic medium layer 12 away from the driving backplane 101, and sequentially penetrates the second inorganic medium layer 12, the first inorganic medium layer 11 and the insulating layer 10 to expose the second anode driving electrode 22. A first end of the second anode 52 is connected to the second light-emitting layer 32, and a second end of the second anode 52 extends along a direction close to the driving backplane 101 and is connected to the second anode driving electrode 22 through the second via.

[0068] In an example embodiment, the second conductive layer 42 is disposed on a side of the second light-emitting layer 32 away from the driving backplane 101. At least part of the second conductive layer 42 overlaps with a projection of the second light-emitting layer 32 on the driving backplane 101 and directly contacts the second light-emitting layer 32. For example, a projection of the second conductive layer 42 on the driving backplane 101 covers a projection of the second light-emitting layer 32 on the driving backplane 101. The second conductive layer 42 comprises a third region and a fourth region. The third region completely overlaps with the projection of the second light-emitting layer 32 on the driving backplane 101 and directly contacts a surface of the second light-emitting layer 32 away from the driving backplane 101. The fourth region does not overlap with the projection of the second light-emitting layer 32 on the driving backplane 101, and the fourth region directly contacts a surface of the third inorganic medium layer 13 away from the driving backplane 101.

[0069] In an example embodiment, a projection of the second conductive layer 42 on the driving backplane 101 covers a projection of the first conductive layer 41 and the first light-emitting layer 31 on the driving backplane 101.

[0070] In an example embodiment, the second light-emitting layer 32 has a visible light transmittance greater than or equal to 80%. For example, the second light-emitting layer 32 has a visible light transmittance greater than or equal to 90%.

[0071] In an example embodiment, the second conductive layer 42 has a visible light transmittance greater than or equal to 80%. For example, the second conductive layer 42 has a visible light transmittance greater than or equal to 90%.

[0072] In an example embodiment, the third light-emitting layer 33 is disposed on the fourth inorganic medium layer 14, the orthographic projection of the third light-emitting layer 33 on the driving backboard 101 does not overlap with the orthographic projection of the fifth inorganic medium layer 15 on the driving backboard 101, the orthographic projection of the third light-emitting layer 33 on the driving backboard 101 does not overlap with the orthographic projection of the cathode driving electrode 24 on the driving backboard 101, and the orthographic projection of the third light-emitting layer 33 on the driving backboard 101 covers the orthographic projection of the third anode driving electrode 23, the first anode driving electrode 21 and the third anode driving electrode 23 on the driving backboard 101; the third light-emitting layer 33 is connected with the third anode driving electrode 23 through the third anode 53, and emits red light.

[0073] In an example embodiment, the orthographic projection of the first light-emitting layer 31, the second light-emitting layer 32 and the third light-emitting layer 33 on the driving backboard 101 exists overlap, for example, the orthographic projection of the third light-emitting layer 33 on the driving backboard 101 covers the orthographic projection of the first light-emitting layer 31 and the second light-emitting layer 32 on the driving backboard 101, and the orthographic projection of the second light-emitting layer 32 on the driving backboard 101 covers the orthographic projection of the first light-emitting layer 31 on the driving backboard 101. The orthographic projection of the third light-emitting layer 33 on the driving backboard 101 exists overlap with the orthographic projection of the third conductive layer 43 on the driving backboard 101.

[0074] In an example embodiment, the area of the orthographic projection of the third light-emitting layer 33 on the driving backboard 101 is 50%-90% of the area of the sub-pixel region 100, for example, the area of the orthographic projection of the third light-emitting layer 33 on the driving backboard 101 is 70%-90% of the area of the sub-pixel region 100.

[0075] The light-emitting substrate of the example embodiment of the present disclosure improves the light-emitting efficiency of the third light-emitting layer by setting the area of the third light-emitting layer to be 50%-90% of the area of the sub-pixel region 100.

[0076] In an example embodiment, the orthographic projection of the third anode 53 on the driving backboard 101 is located in the orthographic projection of the third light-emitting layer 33 on the driving backboard 101. The light-emitting substrate further comprises a third via extending along a direction perpendicular to the driving backboard 101, the third via is formed by a surface of the fourth inorganic medium layer 14 away from the driving backboard 101, and sequentially penetrates the fourth inorganic medium layer 14, the third inorganic medium layer 13, the second inorganic medium layer 12, the first inorganic medium layer 11 and the insulating layer 10 to expose the third anode driving electrode 23. The first end of the third anode 53 is connected with the third light-emitting layer 33, the second end of the third anode 53 extends along a direction close to the driving backboard 101, and is connected with the third anode driving electrode 23 through the third via.

[0077] In an example embodiment, the third conductive layer 43 is disposed on the side of the third light-emitting layer 33 away from the driving backplane 101, at least part of the third conductive layer 43 overlaps the orthographic projection of the third light-emitting layer 33 on the driving backplane 101 and directly contacts the third light-emitting layer 33, for example, the orthographic projection of the third conductive layer 43 on the driving backplane 101 covers the orthographic projection of the third light-emitting layer 33 on the driving backplane 101. The third conductive layer 43 includes a fifth region and a sixth region, the fifth region completely overlaps the orthographic projection of the third light-emitting layer 33 on the driving backplane 101 and directly contacts the surface of the third light-emitting layer 33 away from the driving backplane 101; the sixth region does not overlap the orthographic projection of the third light-emitting layer 33 on the driving backplane 101, and the sixth region directly contacts the surface of the fifth inorganic dielectric layer 15 away from the driving backplane 101.

[0078] In an example embodiment, the orthographic projection of the third conductive layer 43 on the driving backplane 101 covers the orthographic projection of the first conductive layer 41, the first light-emitting layer 31, the second conductive layer 42 and the second light-emitting layer 32 on the driving backplane 101.

[0079] In an example embodiment, the third light-emitting layer 33 has a visible light transmittance of greater than or equal to 80%. For example, the third light-emitting layer 33 has a visible light transmittance of greater than or equal to 90%.

[0080] In an example embodiment, the third conductive layer 43 has a visible light transmittance of greater than or equal to 80%. For example, the third conductive layer 43 has a visible light transmittance of greater than or equal to 90%.

[0081] In an example embodiment, the light-emitting substrate further includes a cathode 60 extending along a direction perpendicular to the driving backplane 101. The light-emitting substrate further includes a fourth via extending along a direction perpendicular to the driving backplane 101, the fourth via is formed by the surface of the fifth inorganic dielectric layer 15 away from the driving backplane 101, sequentially penetrating the fifth inorganic dielectric layer 15, the fourth inorganic dielectric layer 14, the second conductive layer 42, the third inorganic dielectric layer 13, the second inorganic dielectric layer 12, the first conductive layer 41, the first inorganic dielectric layer 11 and the insulating layer 10, and exposing the cathode driving electrode 24. The first end of the cathode 60 is connected to the sixth region of the third conductive layer 43, the second end of the cathode 60 extends along a direction close to the driving backplane 101 and is connected to the cathode driving electrode 24 through the fourth via.

[0082] In an example embodiment, the cathode 60 is electrically connected to the first conductive layer 41, the second conductive layer 42 and the third conductive layer 43, so that the first conductive layer 41, the second conductive layer 42 and the third conductive layer 43 share one cathode 60.

[0083] In the exemplary embodiment, the first conductive layer 41, the first light-emitting layer 31, the first anode 51, and the cathode 60 form a first light-emitting device 110. The first light-emitting layer 31 can emit light under the driving of the first anode 51 and the cathode 60. The second conductive layer 42, the second light-emitting layer 32, the second anode 52, and the cathode 60 form a second light-emitting device 120. The second light-emitting layer 42 can emit light under the driving of the second anode 52 and the cathode 60. The third conductive layer 43, the third light-emitting layer 33, the third anode 53, and the cathode 60 form a third light-emitting device 130. The third light-emitting layer 33 emits light under the driving of the third anode 53 and the cathode 60.

[0084] In the exemplary embodiment, the insulating layer 10 can be made of an inorganic material, for example, silicon oxide or silicon nitride.

[0085] In the exemplary embodiment, the first inorganic medium layer 11 is arranged in the same layer as the first light-emitting layer 31, and the orthographic projection of the first inorganic medium layer 11 and the first light-emitting layer 31 on the driving backboard 101 does not overlap; the third inorganic medium layer 13 is arranged in the same layer as the second light-emitting layer 32, and the orthographic projection of the third inorganic medium layer 13 and the second light-emitting layer 32 on the driving backboard 101 does not overlap; the fifth inorganic medium layer 15 is arranged in the same layer as the third light-emitting layer 33, and the orthographic projection of the fifth inorganic medium layer 15 and the third light-emitting layer 33 on the driving backboard 101 does not overlap; the second inorganic medium layer 12 covers the first conductive layer 41, and the fourth inorganic medium layer 14 covers the second conductive layer 42.

[0086] In the exemplary embodiment, the first inorganic medium layer 11, the second inorganic medium layer 12, the third inorganic medium layer 13, the fourth inorganic medium layer 14, and the fifth inorganic medium layer 15 can all be made of a light-transmitting material, for example, the first inorganic medium layer 11, the second inorganic medium layer 12, the third inorganic medium layer 13, the fourth inorganic medium layer 14, and the fifth inorganic medium layer 15 all have a visible light transmittance greater than or equal to 80%.

[0087] In the exemplary embodiment, the first inorganic medium layer 11, the second inorganic medium layer 12, the third inorganic medium layer 13, the fourth inorganic medium layer 14, and the fifth inorganic medium layer 15 can all be single-film layer structures, for example, the first inorganic medium layer 11, the second inorganic medium layer 12, the third inorganic medium layer 13, the fourth inorganic medium layer 14, and the fifth inorganic medium layer 15 can all include silicon oxide or silicon nitride.

[0088] In the example embodiment, the first inorganic medium layer 11, the second inorganic medium layer 12, the third inorganic medium layer 13, the fourth inorganic medium layer 14 and the fifth inorganic medium layer 15 can all be multi-film layer structures, for example, the first inorganic medium layer 11, the second inorganic medium layer 12, the third inorganic medium layer 13, the fourth inorganic medium layer 14 and the fifth inorganic medium layer 15 can each include a first medium layer and a second medium layer stacked together, the first medium layer is located on the side of the second medium layer close to the driving back plate 101, the first medium layer can include silicon nitride, and the second medium layer can include titanium nitride.

[0089] In the example embodiment, the first inorganic medium layer 11, the second inorganic medium layer 12, the third inorganic medium layer 13, the fourth inorganic medium layer 14 and the fifth inorganic medium layer 15 can be made of the same or different materials.

[0090] The light-emitting substrate of the example embodiment of the present disclosure stacks multiple light-emitting layers along a direction perpendicular to the light-emitting substrate by film layer bonding, avoiding the pressure of mass transfer; by overlapping the multiple light-emitting layers with each other, the light-emitting area is increased and the light-emitting efficiency is improved.

[0091] The light-emitting substrate of the example embodiment of the present disclosure improves the light-emitting efficiency of the second light-emitting layer by making the area of the second light-emitting layer greater than or equal to the area of the first light-emitting layer.

[0092] The light-emitting substrate of the example embodiment of the present disclosure improves the light-emitting efficiency of the third light-emitting layer by making the area of the third light-emitting layer greater than or equal to the area of the second light-emitting layer.

[0093] In the example embodiment, the light-emitting substrate further includes a shielding layer 80, the shielding layer 80 is located in the sub-pixel area 100, the shielding layer 80 is arranged on the side of the third conductive layer 43 away from the driving back plate 101, and the orthogonal projection of the shielding layer 80 on the driving back plate 101 covers the orthogonal projection of the cathode 60 on the driving back plate 101.

[0094] The preparation method of the light-emitting substrate will be described below with reference to FIGS. 2a to 2k.

[0095] The "patterning process" mentioned in the embodiments of the present disclosure includes coating photoresist, mask exposure, development, etching, stripping photoresist and the like for metal materials, inorganic materials or transparent conductive materials, and includes coating organic materials, mask exposure and development and the like for organic materials. Deposition can adopt any one or more of sputtering, evaporation, chemical vapor deposition, coating can adopt any one or more of spraying, spin coating and inkjet printing, etching can adopt any one or more of dry etching and wet etching, and the present disclosure does not make any limitation. "Thin film" refers to a layer of thin film of a certain material on a substrate made by deposition, coating or other processes. If the "thin film" does not need to be patterned during the entire manufacturing process, the "thin film" can also be referred to as a "layer". If the "thin film" needs to be patterned during the entire manufacturing process, it is referred to as a "thin film" before the patterning process and a "layer" after the patterning process. The "layer" after the patterning process contains at least one "pattern".

[0096] Step 101, forming a first anode driving electrode, a second anode driving electrode, a third anode driving electrode and a cathode driving electrode.

[0097] In the exemplary embodiments, forming the first anode driving electrode, the second anode driving electrode, the third anode driving electrode and the cathode driving electrode can include forming the first anode driving electrode 21, the second anode driving electrode 22, the third anode driving electrode 23 and the cathode driving electrode 24 on the substrate, as shown in FIG. 2a.

[0098] Step 102, forming a first light-emitting thin film.

[0099] In the exemplary embodiments, forming the first light-emitting thin film can include bonding the first light-emitting thin film 81 to the first anode driving electrode 21 through the first anode, electrically connecting the first light-emitting thin film 81 to the first anode driving electrode 21 through the first anode, and covering the first anode driving electrode 21, the second anode driving electrode 22, the third anode driving electrode 23 and the cathode driving electrode 24 with the first light-emitting thin film 81, as shown in FIG. 2b.

[0100] Step 103, forming a first light-emitting layer.

[0101] In the example embodiment, forming the first light-emitting layer can include: patterning the first light-emitting thin film by a patterning process on the substrate on which the aforementioned pattern is formed, so that the first light-emitting thin film forms the first light-emitting layer 31, the orthographic projection of the first light-emitting layer 31 on the substrate covers the orthographic projection of the first anode driving electrode 21 on the substrate, and the orthographic projection of the first light-emitting layer 31 on the substrate does not overlap with the orthographic projection of the second anode driving electrode 22, the third anode driving electrode 23 and the cathode driving electrode 24 on the substrate, and the first light-emitting layer 31 is connected with the first anode driving electrode 21 through the first anode, as shown in FIG. 2c.

[0102] Step 104, forming a first inorganic medium layer.

[0103] In the example embodiment, forming the first inorganic medium layer can include: forming the first inorganic medium layer 11 on the substrate on which the aforementioned pattern is formed, so that the first inorganic medium layer 11 covers the second anode driving electrode 22, the third anode driving electrode 23 and the cathode driving electrode 24, and the first inorganic medium layer 11 is arranged in the same layer as the first light-emitting layer 31 and the orthographic projection of the first inorganic medium layer 11 on the substrate does not overlap with the orthographic projection of the first light-emitting layer 31 on the substrate, and the first inorganic medium layer 11 is formed with the first hole exposing the second anode driving electrode 22, the third anode driving electrode 23 and the cathode driving electrode 24, as shown in FIG. 2d.

[0104] Step 105, forming a first conductive layer.

[0105] In the example embodiment, forming the first conductive layer can include: forming the first conductive layer 41 on the first light-emitting layer 31 on the substrate on which the aforementioned pattern is formed, the orthographic projection of the first conductive layer 41 on the substrate covers the orthographic projection of the first light-emitting layer 31 and the cathode driving electrode 24 on the substrate, and the orthographic projection of the first conductive layer 41 on the substrate does not overlap with the orthographic projection of the second anode driving electrode 22 and the third anode driving electrode 23 on the substrate, at least part of the first conductive layer 41 is in direct contact with the first light-emitting layer 31, and at least part of the first conductive layer 41 covers the cathode driving electrode 24 exposed by the first hole, as shown in FIG. 2e.

[0106] Step 106, forming a second inorganic medium layer.

[0107] In the example embodiment, forming the second inorganic medium layer can include: forming the second inorganic medium layer 12 on the first conductive layer on the substrate on which the aforementioned pattern is formed, the second inorganic medium layer 12 covers the first conductive layer, the second anode driving electrode 22 and the third anode driving electrode 23, and the second inorganic medium layer 12 is formed with the second hole exposing the second anode driving electrode 22, the third anode driving electrode 23 and the cathode driving electrode 24, as shown in FIG. 2f.

[0108] Step 107, forming a second light-emitting layer and a third inorganic medium layer.

[0109] In the example embodiment, forming the second light-emitting layer and the third inorganic medium layer can include: bonding the second light-emitting film to the second anode driving electrode through the second anode, so that the second light-emitting film is electrically connected to the second anode driving electrode; then, patterning the second light-emitting film through a patterning process, so that the second light-emitting film forms the second light-emitting layer 32, the orthographic projection of the second light-emitting layer 32 on the substrate covers the orthographic projections of the first anode driving electrode and the second anode driving electrode on the substrate, the orthographic projections of the second light-emitting layer 32 and the third anode driving electrode 23 and the cathode driving electrode 24 on the substrate do not overlap, and the second light-emitting layer 32 is connected to the second anode driving electrode through the second anode; then, forming the third inorganic medium layer 13 covering the third anode driving electrode 23 and the cathode driving electrode 24 on the second inorganic medium layer, the third inorganic medium layer 13 is disposed in the same layer as the second light-emitting layer 32, and the orthographic projections of the third inorganic medium layer 13 and the second light-emitting layer 32 on the substrate do not overlap, and the third inorganic medium layer 13 has the third hole exposing the third anode driving electrode 23 and the cathode driving electrode 24, as shown in FIG. 2g.

[0110] Step 108, forming a second conductive layer.

[0111] In the example embodiment, forming the second conductive layer can include: forming the second conductive layer 42 on the second light-emitting layer 32 on the substrate on which the aforementioned patterns are formed, the orthographic projections of the second conductive layer 42 on the substrate overlap with the orthographic projections of the second light-emitting layer 32 and the cathode driving electrode 24 on the substrate, the orthographic projections of the second conductive layer 42 on the substrate do not overlap with the orthographic projection of the third anode driving electrode 23 on the substrate, at least part of the second conductive layer 42 is in direct contact with the second light-emitting layer 32, and at least part of the second conductive layer 42 covers the cathode driving electrode 24 exposed by the third hole, as shown in FIG. 2h.

[0112] Step 109, forming a fourth inorganic medium layer.

[0113] In the example embodiment, forming the fourth inorganic medium layer can include: forming the fourth inorganic medium layer 14 on the second conductive layer on the substrate on which the aforementioned patterns are formed, the fourth inorganic medium layer 14 covers the second conductive layer, the first anode driving electrode, the second anode driving electrode, the third anode driving electrode, and the cathode driving electrode, and the fourth inorganic medium layer 14 has the fourth hole exposing the third anode driving electrode 23 and the cathode driving electrode 24, as shown in FIG. 2i.

[0114] Step 110, forming a third light-emitting layer and a fifth inorganic medium layer.

[0115] In the example embodiment, forming the third light-emitting layer and the fifth inorganic medium layer can include: forming the third light-emitting layer 33 on the fourth inorganic medium layer 14 on the substrate on which the aforementioned pattern is formed, the third light-emitting layer 33 being connected with the third anode driving electrode through the third anode; the orthographic projection of the third light-emitting layer 33 on the substrate covering the orthographic projection of the first anode driving electrode, the second anode driving electrode and the third anode driving electrode on the substrate, and the orthographic projection of the third light-emitting layer 33 on the substrate not overlapping with the orthographic projection of the cathode driving electrode 24 on the substrate; and then forming the fifth inorganic medium layer 15 covering the cathode driving electrode 24 on the fourth inorganic medium layer 14, the fifth inorganic medium layer 15 being disposed in the same layer as the third light-emitting layer 33, and the orthographic projection of the fifth inorganic medium layer 15 on the substrate not overlapping with the orthographic projection of the third light-emitting layer 33 on the substrate, the fifth inorganic medium layer 15 being formed with the fifth hole exposing the cathode driving electrode 24, as shown in FIG. 2j.

[0116] Step 111, forming a third conductive layer.

[0117] In the example embodiment, forming the third conductive layer can include: forming the third conductive layer 43 on the third light-emitting layer 33 on the substrate on which the aforementioned pattern is formed, the orthographic projection of the third conductive layer 43 on the substrate overlapping with the orthographic projection of the second light-emitting layer, the first light-emitting layer and the cathode driving electrode 24 on the substrate, at least part of the third conductive layer 43 being in direct contact with the third light-emitting layer 33, and at least part of the third conductive layer 43 covering the cathode driving electrode 24 exposed by the fifth hole, as shown in FIG. 2k.

[0118] FIG. 3 is a schematic diagram of the cross-sectional structure of another light-emitting substrate according to an example embodiment of the present disclosure. In the example embodiment, as shown in FIG. 3, the main structure of the light-emitting substrate according to the example embodiment of the present disclosure is substantially the same as that of the light-emitting substrate shown in FIG. 1, except that the light-emitting substrate further includes a non-sub-pixel region 200 disposed at least on one side of the sub-pixel region 100, the cathode driving electrode 24 and the cathode 60 are both located in the non-sub-pixel region 200, at least part of the first conductive layer 41, at least part of the second conductive layer 42 and at least part of the third conductive layer 43 are located in the non-sub-pixel region 200, the first end of the cathode 60 is connected with the third conductive layer 43 located in the non-sub-pixel region 200, and the second end of the cathode 60 extends along the direction close to the driving backplate 101 and is connected with the cathode driving electrode 24.

[0119] In the example embodiment, the cathode 60 is electrically connected with the first conductive layer 41, the second conductive layer 42 and the third conductive layer 43 located in the non-sub-pixel region 200, so that the first conductive layer 41, the second conductive layer 42 and the third conductive layer 43 share one cathode 60.

[0120] In an exemplary embodiment, the cathode driving electrode 24 is annular, and at least part of the cathode driving electrode 24 is arranged around the periphery of the cathode 60 and is in direct contact with the sidewall of the cathode 60.

[0121] In an exemplary embodiment, the light-emitting substrate further comprises a bonding electrode 70 arranged in the sub-pixel region 100, the bonding electrode 70 extends along a direction perpendicular to the light-emitting substrate, and the bonding electrode 70 electrically connects the first conductive layer 41, the second conductive layer 42 and the third conductive layer 43 in the sub-pixel region 100.

[0122] FIG. 4 is a schematic diagram of a cross-sectional structure of another light-emitting substrate according to an exemplary embodiment of the present disclosure. In an exemplary embodiment, as shown in FIG. 4, the main structure of the light-emitting substrate according to the present embodiment is substantially the same as that shown in FIG. 1, except that the second light-emitting layer 32 is bonded to the first light-emitting layer 31 through the first conductive layer 41, the first conductive layer 41 is in direct contact with the first light-emitting layer 31 on the side close to the driving backplate 101, and the first conductive layer 41 is in direct contact with the second light-emitting layer 32 on the side away from the driving backplate 101; the third light-emitting layer 33 is bonded to the second light-emitting layer 32 through the second conductive layer 42, the second conductive layer 42 is in direct contact with the second light-emitting layer 32 on the side close to the driving backplate 101, and the second conductive layer 42 is in direct contact with the third light-emitting layer 33 on the side away from the driving backplate 101.

[0123] In an exemplary embodiment, the second light-emitting layer 32 is bonded to the first light-emitting layer 31 through the first conductive layer 41, and the third light-emitting layer 33 is bonded to the second light-emitting layer 32 through the second conductive layer 42, forming a light-emitting layer series connection group, the light-emitting layer series connection group shares one anode 50 and one cathode 60, the first light-emitting layer 31 on the side close to the driving backplate 101 of the light-emitting layer series connection group is connected to the anode driving electrode 20 through the anode 50, and the third conductive layer 43 on the side away from the driving backplate 101 of the light-emitting layer series connection group is connected to the cathode driving electrode 24 through the cathode 60. The light-emitting layers in the light-emitting layer series connection group share one anode 50 and one cathode 60.

[0124] In an exemplary embodiment, the first light-emitting layer 31, the second light-emitting layer 32, the third light-emitting layer 33, the first conductive layer 41 and the second conductive layer 42 have complete overlapping orthographic projections on the driving backplate 101.

[0125] In an exemplary embodiment, the first conductive layer 41, the second conductive layer 42 and the third conductive layer 43 each comprise a metal oxide, for example, indium tin oxide or indium zinc oxide.

[0126] FIG. 5 is a schematic diagram of a cross-sectional structure of another light-emitting substrate according to an example embodiment of the present disclosure. In the example embodiment, the main structure of the light-emitting substrate according to the example embodiment of the present disclosure is substantially the same as that shown in FIG. 1, except that the first light-emitting layer 31 is connected with the first anode 51 and the first cathode 61, respectively; the second light-emitting layer 32 is disposed on the side of the first light-emitting layer 31 away from the driving backplane 101 and is insulated from the first light-emitting layer 31, the orthographic projection of the second light-emitting layer 32 on the driving backplane 101 covers the orthographic projection of the first light-emitting layer 31 on the driving backplane 101, the second light-emitting layer 32 is connected with the second anode 52 and the second cathode 62, respectively; the third light-emitting layer 33 is disposed on the side of the second light-emitting layer 32 away from the driving backplane 101 and is insulated from the second light-emitting layer 32, the orthographic projection of the third light-emitting layer 33 on the driving backplane 101 covers the orthographic projection of the second light-emitting layer 32 on the driving backplane 101, and the third light-emitting layer 33 is connected with the third anode 53 and the third cathode 63, respectively.

[0127] The present disclosure also provides a method for manufacturing a light-emitting substrate, comprising:

[0128] disposing at least two light-emitting layers on the driving backplane in sequence, the at least two light-emitting layers being disposed in sequence along the thickness direction of the driving backplane, the orthographic projections of the at least two light-emitting layers on the driving backplane overlap, and the area of the orthographic projection of the light-emitting layer closer to the driving backplane in the adjacent light-emitting layers on the driving backplane is less than or equal to the area of the orthographic projection of the light-emitting layer farther away from the driving backplane in the adjacent light-emitting layers on the driving backplane.

[0129] The present disclosure also provides a display device comprising the light-emitting substrate according to the example embodiments described above. The display device can be any product or component with display function, such as a mobile phone, a tablet computer, a television, a display, a notebook computer, a digital photo frame, a navigator, etc.

[0130] The drawings in the present disclosure only involve the structures related to the present disclosure, and other structures can be referred to the general design. In the case of no conflict, the features in the embodiments of the present disclosure can be combined with each other to obtain new embodiments.

[0131] Those skilled in the art should understand that the technical solutions of the present disclosure can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present disclosure, and all should be covered in the scope of the claims of the present disclosure.

Claims

1. A light-emitting substrate comprising at least one sub-pixel region, the sub-pixel region comprising a driving backplane and at least two light-emitting devices disposed on the driving backplane, each of the at least two light-emitting devices comprising a light-emitting layer, the light-emitting layers of the at least two light-emitting devices being disposed in sequence along a thickness direction of the driving backplane, the orthographic projections of the light-emitting layers of the at least two light-emitting devices on the driving backplane overlap, and the area of the orthographic projection of the light-emitting layer closer to the driving backplane in adjacent light-emitting layers is less than or equal to the area of the orthographic projection of the light-emitting layer farther from the driving backplane in the adjacent light-emitting layers.

2. The light-emitting substrate of claim 1, comprising a first light-emitting layer, a second light-emitting layer, and a third light-emitting layer disposed in sequence along a direction away from the driving backplane, the orthographic projections of the first light-emitting layer, the second light-emitting layer, and the third light-emitting layer on the driving backplane overlap, the area of the orthographic projection of the first light-emitting layer on the driving backplane is less than or equal to the area of the orthographic projection of the second light-emitting layer on the driving backplane, and the area of the orthographic projection of the second light-emitting layer on the driving backplane is less than or equal to the area of the orthographic projection of the third light-emitting layer on the driving backplane.

3. The light-emitting substrate of claim 2, wherein, The orthographic projection of the first light-emitting layer on the driving backplane is located in the orthographic projection of the second light-emitting layer on the driving backplane, and the orthographic projection of the second light-emitting layer on the driving backplane is located in the orthographic projection of the third light-emitting layer on the driving backplane.

4. The light-emitting substrate of claim 2, wherein, The area of the orthographic projection of the first light-emitting layer on the driving backplane is 10%-50% of the area of the sub-pixel region, the area of the orthographic projection of the second light-emitting layer on the driving backplane is 30%-80% of the area of the sub-pixel region, and the area of the orthographic projection of the third light-emitting layer on the driving backplane is 50%-90% of the area of the sub-pixel region.

5. The light-emitting substrate of claim 2, wherein, The first light-emitting layer is configured to emit blue light, the second light-emitting layer is configured to emit green light, and the third light-emitting layer is configured to emit red light.

6. The light-emitting substrate according to any one of claims 1 to 5, wherein The driving backplane comprises an anode driving electrode, and the light-emitting device further comprises an anode, a first end of the anode being connected to the light-emitting layer, and a second end of the anode being connected to the anode driving electrode.

7. The light-emitting substrate of claim 6, wherein, The driving backplane comprises at least two anode driving electrodes, the light-emitting layers of adjacent light-emitting devices are insulated from each other, and the anodes of the adjacent light-emitting devices are connected to the at least two anode driving electrodes correspondingly.

8. The light-emitting substrate of claim 6, wherein, The light-emitting layers of adjacent light-emitting devices are connected in series to form a light-emitting layer series connection group, the light-emitting layer series connection group shares an anode, and the light-emitting layer closer to the driving backplane of the light-emitting layer series connection group is connected to the anode driving electrode through the shared anode.

9. The light emitting substrate of any of claims 1 to 5, wherein, The driving backplane comprises a cathode driving electrode, the light-emitting device further comprises a conductive layer, the conductive layer is disposed on a side of the light-emitting layer away from the driving backplane, at least part of the conductive layer is in direct contact with the light-emitting layer, and the light-emitting device further comprises a cathode, the conductive layer is connected to the cathode driving electrode through the cathode.

10. The light-emitting substrate of claim 9, wherein, The conductive layers of the at least two light-emitting devices share a cathode.

11. The light-emitting substrate of claim 9, wherein, The adjacent light-emitting layers are connected in series through the conductive layers to form a light-emitting layer series connection group, the light-emitting layer series connection group shares a cathode, and the conductive layer on the side of the light-emitting layer series connection group away from the driving backplate is connected to the cathode driving electrode through the shared cathode.

12. The light-emitting substrate of claim 9, further comprising an inorganic medium layer, the inorganic medium layer is in direct contact with the conductive layer on the side close to the driving backplate, and the inorganic medium layer is in direct contact with the light-emitting layer on the side away from the driving backplate.

13. The light emitting substrate of claim 9, wherein, The cathode driving electrode is located in the sub-pixel area, or the light-emitting substrate further comprises a non-sub-pixel area on at least one side of the sub-pixel area, and the cathode driving electrode is located in the non-sub-pixel area.

14. The light emitting substrate of claim 9, wherein, The cathode driving electrode is annular, and at least part of the cathode driving electrode is arranged around the periphery of the cathode and is in direct contact with the side wall of the cathode.

15. A display device comprising the light-emitting substrate of any one of claims 1 to 14.

16. A method for manufacturing a light-emitting substrate, comprising: sequentially arranging at least two light-emitting layers on a driving backplate, the at least two light-emitting layers are sequentially arranged along the thickness direction of the driving backplate, the orthographic projections of the at least two light-emitting layers on the driving backplate overlap, and the area of the orthographic projection of the light-emitting layer close to the driving backplate in the adjacent light-emitting layers on the driving backplate is less than or equal to the area of the orthographic projection of the light-emitting layer away from the driving backplate in the adjacent light-emitting layers on the driving backplate.

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