Light-emitting substrate, preparation method thereof and display device
Patent Information
- Application Number
- CN202480000665.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-29
- Publication Date
- 2025-12-09
AI Technical Summary
The existing light emitting substrate has a small light emitting area, which affects the display effect.
A light-emitting substrate is designed, comprising light-emitting layers of at least two light-emitting devices arranged in sequence along the thickness direction of a driving backplane. The orthographic projections of adjacent light-emitting layers overlap and are electrically connected through an anode and a cathode to form a series group of light-emitting layers, thereby increasing the light-emitting area.
By increasing the light-emitting area, the light-emitting efficiency is increased and the display effect is improved.
Smart Images
Figure CN121100599A_ABST
Abstract
Description
Luminescent substrate, preparation method thereof, and display device Technical Field
[0001] The present disclosure relates to, but is not limited to, the field of display technology, and specifically to a light-emitting substrate and a preparation method thereof, and a display device. Background Art
[0002] The manufacturing size of light emitting diodes (LEDs) has a trend of becoming increasingly smaller. For example, micro light emitting diodes (Micro LEDs) or sub-millimeter light emitting diodes (Mini LEDs) are gaining more and more attention due to their advantages such as small size, low power consumption, and long product life.
[0003] The light-emitting substrate can use light-emitting diodes to display images, and multiple light-emitting diodes emitting different colors are arranged side by side to achieve 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 of the Invention
[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] On the one hand, the present disclosure provides a light-emitting substrate, comprising at least one sub-pixel area, wherein the sub-pixel area comprises a driving backplane and at least two light-emitting devices arranged on the driving backplane, wherein the at least two light-emitting devices each comprise a light-emitting layer, and the light-emitting layers of the at least two light-emitting devices are arranged in sequence along the thickness direction of the driving backplane, and the light-emitting layers of the at least two light-emitting devices have overlapping orthographic projections on the driving backplane, and the area of the orthographic projection of the light-emitting layer close 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 far 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 in 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 exemplary embodiment, 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.
[0009] In an exemplary 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 exemplary 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 exemplary embodiment, the driving backplane includes an anode driving electrode, and the light emitting device further includes an anode, a first end of the anode is connected to the light emitting layer, and a second end of the anode is connected to the anode driving electrode.
[0012] In an exemplary embodiment, the driving backplane includes at least two anode driving electrodes, the light-emitting layers of adjacent light-emitting devices are insulated from each other, and the anodes of adjacent light-emitting devices are correspondingly connected to the at least two anode driving electrodes.
[0013] In an exemplary embodiment, the light-emitting layers of adjacent light-emitting devices are connected in series to form a light-emitting layer series group, which shares a common anode. The light-emitting layers of the light-emitting layer series group close to the driving backplane are connected to the anode driving electrode through the common anode.
[0014] In an exemplary embodiment, the driving backplane includes a cathode driving electrode, the light-emitting device also includes 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 also includes a cathode, and the conductive layer is connected to the cathode driving electrode through the cathode.
[0015] In an exemplary embodiment, the conductive layers of the at least two light emitting devices share a cathode.
[0016] In an exemplary embodiment, the adjacent light-emitting layers are connected in series through the conductive layer to form a light-emitting layer series group, the light-emitting layer series group shares a cathode, and the conductive layer of the light-emitting layer series group away from the driving backplane is connected to the cathode driving electrode through the shared cathode.
[0017] In an exemplary embodiment, an inorganic dielectric layer is further included. A side of the inorganic dielectric layer close to the driving backplane is in direct contact with the conductive layer, and a side of the inorganic dielectric layer away from the driving backplane is in direct contact with the light-emitting layer.
[0018] In an exemplary embodiment, the cathode driving electrode is located in the sub-pixel area, or the light emitting substrate further includes a non-sub-pixel area located at least one side of the sub-pixel area, and the cathode driving electrode is located in the non-sub-pixel area.
[0019] In an exemplary embodiment, the cathode driving electrode is ring-shaped, and at least a portion of the cathode driving electrode is disposed around the cathode and directly contacts a side wall of the cathode.
[0020] On the other hand, the present disclosure further provides a display device comprising the aforementioned light-emitting substrate.
[0021] In another aspect, the present disclosure further provides a method for preparing a light-emitting substrate, comprising:
[0022] At least two light-emitting layers are sequentially arranged on the driving backplane, and the at least two light-emitting layers are sequentially arranged 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 close to the driving backplane among 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 far from the driving backplane among adjacent light-emitting layers on the driving backplane.
[0023] Still other aspects will become apparent upon reading and understanding the accompanying drawings and detailed description. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The accompanying drawings are used to provide an understanding of the technical solution of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present application and do not constitute a limitation on the technical solution of the present application.
[0025] FIG1 is a schematic cross-sectional view of a light-emitting substrate according to an exemplary embodiment of the present disclosure;
[0026] FIG2a is a schematic diagram of a preparation process of a light-emitting substrate after forming a first anode driving electrode, a second anode driving electrode, a third anode driving electrode, and a cathode driving electrode according to an exemplary embodiment of the present disclosure;
[0027] FIG2 b is a schematic diagram of a preparation process of a light-emitting substrate after forming a first light-emitting thin film according to an exemplary embodiment of the present disclosure;
[0028] FIG2 c is a schematic diagram of a preparation process of a light-emitting substrate after forming a first light-emitting layer according to an exemplary embodiment of the present disclosure;
[0029] FIG2 d is a schematic diagram of a preparation process of a light-emitting substrate after forming a first inorganic dielectric layer according to an exemplary embodiment of the present disclosure;
[0030] FIG2e is a schematic diagram of a preparation process of a light-emitting substrate after forming a first conductive layer according to an exemplary embodiment of the present disclosure;
[0031] FIG2 f is a schematic diagram of a preparation process of a light-emitting substrate after forming a second inorganic dielectric layer according to an exemplary embodiment of the present disclosure;
[0032] FIG2g is a schematic diagram of a preparation process of a light-emitting substrate after forming a second light-emitting layer and a third inorganic dielectric layer according to an exemplary embodiment of the present disclosure;
[0033] FIG2h is a schematic diagram of a preparation process of a light-emitting substrate after forming a second conductive layer according to an exemplary embodiment of the present disclosure;
[0034] FIG2i is a schematic diagram of a preparation process of a light-emitting substrate after forming a fourth inorganic dielectric layer according to an exemplary embodiment of the present disclosure;
[0035] FIG2j is a schematic diagram of a preparation process of a light-emitting substrate after forming a third light-emitting layer and a fifth inorganic medium layer according to an exemplary embodiment of the present disclosure;
[0036] FIG2k is a schematic diagram of a preparation process of a light-emitting substrate after forming a third conductive layer according to an exemplary embodiment of the present disclosure;
[0037] FIG3 is a schematic cross-sectional view of another light-emitting substrate according to an exemplary embodiment of the present disclosure;
[0038] FIG4 is a schematic cross-sectional view of another light-emitting substrate according to an exemplary embodiment of the present disclosure;
[0039] FIG5 is a schematic cross-sectional view of another light-emitting substrate according to an exemplary embodiment of the present disclosure. DETAILED DESCRIPTION
[0040] In order to make the purpose, technical solutions and advantages of the present disclosure clearer, the embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. Note that the embodiments can be implemented in a variety of different forms. A person of ordinary skill in the art can easily understand the fact that the methods and contents can be transformed into various forms without departing from the purpose 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. In the absence of conflict, the embodiments in the present disclosure and the features in the embodiments can be arbitrarily combined with each other.
[0041] In the drawings, the sizes of various components, layer thicknesses, or regions may be exaggerated for clarity. Therefore, one embodiment of the present disclosure is not necessarily limited to these dimensions, and the shapes and sizes of the components in the drawings do not reflect true proportions. Furthermore, the drawings schematically illustrate idealized examples, and one embodiment of the present disclosure is not limited to the shapes or numerical values shown in the drawings.
[0042] In this specification, ordinal numbers such as “first”, “second” and “third” are provided to avoid confusion among constituent elements, and are not intended to limit the number.
[0043] In this specification, for convenience, words and phrases indicating orientation or positional relationships, such as "middle," "upper," "lower," "front," "back," "vertical," "horizontal," "top," "bottom," "inside," and "outside," are used to illustrate the positional relationships of constituent elements with reference to the accompanying drawings. This is merely for the purpose of facilitating the description of this specification and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limiting the present disclosure. The positional relationships of constituent elements may be appropriately changed depending on the direction in which each constituent element is described. Therefore, the present disclosure is not limited to the words and phrases described in the specification and may be appropriately replaced according to the circumstances.
[0044] In this specification, unless otherwise specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they can refer to fixed, removable, or integral connections; mechanical or electrical connections; direct connections, indirect connections through intermediaries, or internal communication between two components. Those skilled in the art will understand the specific meanings of these terms in this disclosure.
[0045] In this specification, a transistor refers to a device that includes at least three terminals: a gate electrode, a drain electrode, and a source electrode. A transistor has a channel region between a drain electrode (drain electrode terminal, drain region, or drain electrode) and a source electrode (source electrode terminal, source region, or source electrode), and current can flow through the drain electrode, the channel region, and the source electrode. Note that in this specification, the channel region refers to the region through which current primarily flows.
[0046] In this specification, the first electrode can be a drain electrode and the second electrode can be a source electrode, or vice versa. The functions of "source electrode" and "drain electrode" may be interchanged when using transistors with opposite polarity or when the direction of current changes during circuit operation. Therefore, in this specification, "source electrode" and "drain electrode" may be interchanged.
[0047] In this specification, "electrically connected" includes components connected together via an element having some electrical function. There are no particular limitations on the "element having some electrical function" as long as it enables the transfer of electrical signals between the connected components. Examples of "element having some electrical function" include not only electrodes and wiring, but also switching elements such as transistors, resistors, inductors, capacitors, and other components with various functions.
[0048] In this specification, "parallel" refers to a state where the angle formed by two straight lines is greater than -10° and less than 10°, and thus also includes a state where the angle is greater than -5° and less than 5°. Furthermore, "perpendicular" refers to a state where the angle formed by two straight lines is greater than 80° and less than 100°, and thus also includes a state where the angle is greater than 85° and less than 95°.
[0049] In this specification, the terms "film" and "layer" may be interchanged. For example, "conductive layer" may be replaced with "conductive film." Similarly, "insulating film" may be replaced with "insulating layer."
[0050] The term "about" in the present disclosure refers to a numerical value that is not strictly defined and allows for process and measurement errors.
[0051] An exemplary embodiment of the present disclosure provides a light-emitting substrate, comprising at least one sub-pixel area, wherein the sub-pixel area comprises a driving backplane and at least two light-emitting devices arranged on the driving backplane, wherein the at least two light-emitting devices each comprise a light-emitting layer, and the light-emitting layers of the at least two light-emitting devices are sequentially arranged along the thickness direction of the driving backplane, and 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 close to the driving backplane among 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 far from the driving backplane among adjacent light-emitting layers on the driving backplane.
[0052] The solution of this embodiment is illustrated below through some examples.
[0053] FIG1 is a schematic diagram of the cross-sectional structure of a light-emitting substrate according to an exemplary embodiment of the present disclosure. In an exemplary embodiment, as shown in FIG1 , the light-emitting substrate according to the present disclosure includes a sub-pixel region 100 in a direction perpendicular to the light-emitting substrate. The sub-pixel region 100 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 dielectric layer 11 disposed on the side of the insulating layer 10 away from the driving backplane 101, a first conductive layer 41 disposed on the side of the first light-emitting layer 31 and the first inorganic dielectric layer 11 away from the driving backplane 101, and a second inorganic dielectric layer 12 disposed on the side of the first conductive layer 41 away from the driving backplane 101. The second light-emitting layer 32 and the third inorganic dielectric layer 13 are disposed on the side of the second inorganic dielectric layer 12 away from the driving backplane 101; the second conductive layer 42 is disposed on the side of the second light-emitting layer 32 and the third inorganic dielectric layer 13 away from the driving backplane 101; the fourth inorganic dielectric layer 14 is disposed on the side of the second conductive layer 42 away from the driving backplane 101; the third light-emitting layer 33 and the fifth inorganic dielectric layer 15 are disposed on the side of the fourth inorganic dielectric layer 14 away from the driving backplane 101; and the third conductive layer 43 is disposed on the side of the third light-emitting layer 33 and the fifth inorganic dielectric layer 15 away from the driving backplane 101. A first anode 51 is disposed on the side of the first light-emitting layer 31 close to the driving backplane 101; a second anode 52 is disposed on the side of the second light-emitting layer 32 close to the driving backplane 101; and a third anode 53 is disposed on the side of the third light-emitting layer 33 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 exemplary 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; and 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 exemplary 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 an exemplary embodiment, the first light-emitting layer 31 is arranged on the insulating layer 10, and the first light-emitting layer 31 is arranged on the same layer as the first inorganic medium layer 11, and their orthographic projections on the driving backplane 101 do not overlap, and the first light-emitting layer 31 does not overlap with the orthographic projections of the second anode driving electrode 22, the third anode driving electrode 23 and the cathode driving electrode 24 on the driving backplane 101. The orthographic projection of the first light-emitting layer 31 on the driving backplane 101 covers the orthographic projection of the first anode driving electrode 21 on the driving backplane 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 an exemplary embodiment, the area of the orthographic projection of the first light-emitting layer 31 on the driving backplane 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 backplane 101 is 30%-50% of the area of the sub-pixel region 100 .
[0058] The light-emitting substrate of the embodiment of the present disclosure ensures that the luminous efficiency of the first light-emitting layer is substantially the same as that of the second light-emitting layer and the third light-emitting layer by making the area of the first light-emitting layer 10%-50% of the area of the sub-pixel region 100 .
[0059] In an exemplary embodiment, the first anode 51 extends in a direction perpendicular to the driving backplate 101. The orthographic projection of the first anode 51 on the driving backplate 101 is located within the orthographic projection of the first light-emitting layer 31 on the driving backplate 101. The light-emitting substrate further includes a first via extending in a direction perpendicular to the driving backplate 101. The first via extends from the 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. The first end of the first anode 51 is connected to the first light-emitting layer 31, and the second end of the first anode 51 extends in a direction close to the driving backplate 101 and is connected to the first anode driving electrode 21 through the first via.
[0060] In an exemplary embodiment, the first conductive layer 41 is disposed on a side of the first light-emitting layer 31 away from the driver backplate 101. At least a portion of the first conductive layer 41 overlaps with and is in direct contact with the orthographic projection of the first light-emitting layer 31 on the driver backplate 101. For example, the orthographic projection of the first conductive layer 41 on the driver backplate 101 covers the orthographic projection of the first light-emitting layer 31 on the driver backplate 101. The first conductive layer 41 includes 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 driver backplate 101 and is in direct contact with the surface of the first light-emitting layer 31 away from the driver backplate 101. The second region does not overlap with the orthographic projection of the first light-emitting layer 31 on the driver backplate 101 and is in direct contact with the surface of the first inorganic dielectric layer 11 away from the driver backplate 101.
[0061] In an exemplary embodiment, the transmittance of the first light emitting layer 31 to visible light is greater than or equal to 80%. For example, the transmittance of the first light emitting layer 31 to visible light is greater than or equal to 90%.
[0062] In an exemplary embodiment, the transmittance of the first conductive layer 41 to visible light is greater than or equal to 80%. For example, the transmittance of the first conductive layer 41 to visible light is greater than or equal to 90%.
[0063] In an exemplary embodiment, the second light-emitting layer 32 is disposed on the second inorganic dielectric layer 12, and the second light-emitting layer 32 does not overlap with the orthographic projections of the third inorganic dielectric layer 13 on the driving backplane 101. The second light-emitting layer 32 does not overlap with the orthographic projections of the third anode driving electrode 23 and the cathode driving electrode 24 on the driving backplane 101. The orthographic projection of the second light-emitting layer 32 on the driving backplane 101 covers the orthographic projections of the first anode driving electrode 21 and the second anode driving electrode 22 on the driving backplane 101; the second light-emitting layer 32 is connected to 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 orthographic projections of the second light-emitting layer 32 and the first light-emitting layer 31 on the driving backplane 101 overlap. For example, 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 orthographic projections of the second light-emitting layer 32 and the second conductive layer 42 on the driving backplane 101 overlap.
[0065] In an exemplary embodiment, the area of the orthographic projection of the second light-emitting layer 32 on the driving backplane 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 backplane 101 is 50%-80% of the area of the sub-pixel region 100 .
[0066] The light-emitting substrate of the 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 30%-80% of the area of the sub-pixel region 100 .
[0067] In an exemplary embodiment, the second anode 52 extends in a direction perpendicular to the driving backplate 101. The orthographic projection of the second anode 52 on the driving backplate 101 is located within the orthographic projection of the second light-emitting layer 32 on the driving backplate 101. The light-emitting substrate further includes a second via extending in a direction perpendicular to the driving backplate 101. The second via extends from the surface of the second inorganic dielectric layer 12 on the side away from the driving backplate 101, sequentially passing through the second inorganic dielectric layer 12, the first inorganic dielectric layer 11, and the insulating layer 10, exposing the second anode driving electrode 22. The first end of the second anode 52 is connected to the second light-emitting layer 32, and the second end of the second anode 52 extends in a direction close to the driving backplate 101 and is connected to the second anode driving electrode 22 through the second via.
[0068] In an exemplary embodiment, the second conductive layer 42 is disposed on a side of the second light-emitting layer 32 away from the driver backplate 101. At least a portion of the second conductive layer 42 overlaps with and is in direct contact with the orthographic projection of the second light-emitting layer 32 on the driver backplate 101. For example, the orthographic projection of the second conductive layer 42 on the driver backplate 101 covers the orthographic projection of the second light-emitting layer 32 on the driver backplate 101. The second conductive layer 42 includes a third region and a fourth region. The third region completely overlaps with the orthographic projection of the second light-emitting layer 32 on the driver backplate 101 and is in direct contact with the surface of the second light-emitting layer 32 away from the driver backplate 101. The fourth region does not overlap with the orthographic projection of the second light-emitting layer 32 on the driver backplate 101 and is in direct contact with the surface of the third inorganic dielectric layer 13 away from the driver backplate 101.
[0069] In an exemplary embodiment, the orthographic projection of the second conductive layer 42 on the driving backplane 101 covers the orthographic projections of the first conductive layer 41 and the first light emitting layer 31 on the driving backplane 101 .
[0070] In an exemplary embodiment, the transmittance of the second light emitting layer 32 to visible light is greater than or equal to 80%. For example, the transmittance of the second light emitting layer 32 to visible light is greater than or equal to 90%.
[0071] In an exemplary embodiment, the transmittance of the second conductive layer 42 to visible light is greater than or equal to 80%. For example, the transmittance of the second conductive layer 42 to visible light is greater than or equal to 90%.
[0072] In an exemplary embodiment, the third light-emitting layer 33 is arranged on the fourth inorganic dielectric layer 14, the orthographic projections of the third light-emitting layer 33 and the fifth inorganic dielectric layer 15 on the driving backplane 101 do not overlap, the orthographic projections of the third light-emitting layer 33 and the cathode driving electrode 24 on the driving backplane 101 do not overlap, and the orthographic projections of the third light-emitting layer 33 on the driving backplane 101 cover the orthographic projections of the third anode driving electrode 23, the first anode driving electrode 21 and the third anode driving electrode 23 on the driving backplane 101; the third light-emitting layer 33 is connected to the third anode driving electrode 23 through the third anode 53, and emits red light.
[0073] In an exemplary embodiment, the orthographic projections of the first light-emitting layer 31, the second light-emitting layer 32, and the third light-emitting layer 33 on the driving backplane 101 overlap. For example, the orthographic projection of the third light-emitting layer 33 on the driving backplane 101 covers the orthographic projections of the first light-emitting layer 31 and the second light-emitting layer 32 on the driving backplane 101, and 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 312 on the driving backplane 101. The orthographic projections of the third light-emitting layer 33 and the third conductive layer 43 on the driving backplane 101 overlap.
[0074] In an exemplary embodiment, the area of the orthographic projection of the third light-emitting layer 33 on the driving backplane 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 backplane 101 is 70%-90% of the area of the sub-pixel region 100 .
[0075] The light-emitting substrate of the 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 50%-90% of the area of the sub-pixel region 100 .
[0076] In an exemplary embodiment, the orthographic projection of the third anode 53 on the driving backplate 101 is located within the orthographic projection of the third light-emitting layer 33 on the driving backplate 101. The light-emitting substrate further includes a third via extending in a direction perpendicular to the driving backplate 101. The third via extends from the surface of the fourth inorganic dielectric layer 14 on the side away from the driving backplate 101, and sequentially penetrates the fourth inorganic dielectric layer 14, the third inorganic dielectric layer 13, the second inorganic dielectric layer 12, the first inorganic dielectric layer 11, and the insulating layer 10, exposing the third anode driving electrode 23. The first end of the third anode 53 is connected to the third light-emitting layer 33, and the second end of the third anode 53 extends in a direction close to the driving backplate 101 and is connected to the third anode driving electrode 23 through the third via.
[0077] In an exemplary embodiment, the third conductive layer 43 is disposed on a side of the third light-emitting layer 33 away from the driving backplate 101. At least a portion of the third conductive layer 43 overlaps with and is in direct contact with the orthographic projection of the third light-emitting layer 33 on the driving backplate 101. For example, the orthographic projection of the third conductive layer 43 on the driving backplate 101 covers the orthographic projection of the third light-emitting layer 33 on the driving backplate 101. The third conductive layer 43 includes a fifth region and a sixth region. The fifth region completely overlaps with the orthographic projection of the third light-emitting layer 33 on the driving backplate 101 and is in direct contact with the surface of the third light-emitting layer 33 away from the driving backplate 101. The sixth region does not overlap with the orthographic projection of the third light-emitting layer 33 on the driving backplate 101 and is in direct contact with the surface of the fifth inorganic dielectric layer 15 away from the driving backplate 101.
[0078] In an exemplary embodiment, the orthographic projection of the third conductive layer 43 on the driving backplane 101 covers the orthographic projections 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 exemplary embodiment, the third light emitting layer 33 has a transmittance of visible light greater than or equal to 80%. For example, the transmittance of the third light emitting layer 33 has a transmittance of visible light greater than or equal to 90%.
[0080] In an exemplary embodiment, the third conductive layer 43 has a visible light transmittance greater than or equal to 80%. For example, the third conductive layer 43 has a visible light transmittance greater than or equal to 90%.
[0081] In an exemplary embodiment, the light-emitting substrate further includes a cathode 60, which extends perpendicularly to the driving backplate 101. The light-emitting substrate further includes a fourth via extending perpendicularly to the driving backplate 101. The fourth via extends from the surface of the fifth inorganic dielectric layer 15 on the side away from the driving backplate 101, and sequentially penetrates 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, 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, and the second end of the cathode 60 extends in a direction close to the driving backplate 101 and is connected to the cathode driving electrode 24 through the fourth via.
[0082] In an exemplary 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 when driven by 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 when driven by 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 when driven by the third anode 53 and the cathode 60.
[0084] In exemplary embodiments, the insulating layer 10 may employ an inorganic material, for example, silicon oxide or silicon nitride.
[0085] In an exemplary embodiment, the first inorganic dielectric layer 11 is arranged on the same layer as the first light-emitting layer 31, and the orthographic projections of the first inorganic dielectric layer 11 and the first light-emitting layer 31 on the driving backplane 101 do not overlap; the third inorganic dielectric layer 13 is arranged on the same layer as the second light-emitting layer 32, and the orthographic projections of the third inorganic dielectric layer 13 and the second light-emitting layer 32 on the driving backplane 101 do not overlap; the fifth inorganic dielectric layer 15 is arranged on the same layer as the third light-emitting layer 33, and the orthographic projections of the fifth inorganic dielectric layer 15 and the third light-emitting layer 33 on the driving backplane 101 do not overlap; the second inorganic dielectric layer 12 covers the first conductive layer 41, and the fourth inorganic dielectric layer 14 covers the second conductive layer 42.
[0086] In an exemplary embodiment, the first inorganic dielectric layer 11, the second inorganic dielectric layer 12, the third inorganic dielectric layer 13, the fourth inorganic dielectric layer 14 and the fifth inorganic dielectric layer 15 can all be made of light-transmitting materials. For example, the first inorganic dielectric layer 11, the second inorganic dielectric layer 12, the third inorganic dielectric layer 13, the fourth inorganic dielectric layer 14 and the fifth inorganic dielectric layer 15 all have a transmittance to visible light greater than or equal to 80%.
[0087] In an exemplary embodiment, the first inorganic dielectric layer 11, the second inorganic dielectric layer 12, the third inorganic dielectric layer 13, the fourth inorganic dielectric layer 14 and the fifth inorganic dielectric layer 15 can all be single-layer structures. For example, the first inorganic dielectric layer 11, the second inorganic dielectric layer 12, the third inorganic dielectric layer 13, the fourth inorganic dielectric layer 14 and the fifth inorganic dielectric layer 15 can all include silicon oxide or silicon nitride.
[0088] In an exemplary embodiment, the first inorganic dielectric layer 11, the second inorganic dielectric layer 12, the third inorganic dielectric layer 13, the fourth inorganic dielectric layer 14 and the fifth inorganic dielectric layer 15 can all be multi-layer structures. For example, the first inorganic dielectric layer 11, the second inorganic dielectric layer 12, the third inorganic dielectric layer 13, the fourth inorganic dielectric layer 14 and the fifth inorganic dielectric layer 15 can all include a first dielectric layer and a second dielectric layer that are stacked, and the first dielectric layer is located on the side of the second dielectric layer close to the driving backplane 101. The first dielectric layer may include silicon nitride, and the second dielectric layer may include titanium nitride.
[0089] In exemplary embodiments, the first inorganic dielectric layer 11 , the second inorganic dielectric layer 12 , the third inorganic dielectric layer 13 , the fourth inorganic dielectric layer 14 , and the fifth inorganic dielectric layer 15 may be made of the same or different materials.
[0090] The light-emitting substrate of the embodiment of the present disclosure stacks multiple light-emitting layers in a direction perpendicular to the light-emitting substrate by means of film layer bonding, thereby avoiding the pressure of massive transfer; by overlapping multiple light-emitting layers, the light-emitting area is increased and the light-emitting efficiency is improved.
[0091] The light-emitting substrate of the 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 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 an exemplary embodiment, the light-emitting substrate further includes a shielding layer 80, which is located in the sub-pixel area 100, and the shielding layer 80 is arranged on the side of the third conductive layer 43 away from the driving backplane 101, and the orthographic projection of the shielding layer 80 on the driving backplane 101 covers the orthographic projection of the cathode 60 on the driving backplane 101.
[0094] The following is an exemplary description of a method for preparing a light-emitting substrate with reference to FIG. 2 a to FIG. 2 k .
[0095] The "patterning process" mentioned in the embodiments of the present disclosure includes processes such as coating photoresist, mask exposure, development, etching, and stripping photoresist for metal materials, inorganic materials, or transparent conductive materials, and includes processes such as coating organic materials, mask exposure, and development for organic materials. Deposition can be carried out by any one or more of sputtering, evaporation, and chemical vapor deposition, coating can be carried out by any one or more of spraying, spin coating, and inkjet printing, and etching can be carried out by any one or more of dry etching and wet etching, which are not limited in the present disclosure. "Thin film" refers to a layer of thin film made by deposition, coating, or other processes of a certain material on a substrate. If the "thin film" does not require a patterning process during the entire production process, the "thin film" can also be called a "layer". If the "thin film" requires a patterning process during the entire production process, it is called 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 an exemplary embodiment, forming the first anode driving electrode, the second anode driving electrode, the third anode driving electrode and the cathode driving electrode may 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 Figure 2a.
[0098] Step 102: forming a first light-emitting thin film.
[0099] In an exemplary embodiment, forming the first light-emitting film may include: on the substrate on which the aforementioned pattern is formed, bonding the first light-emitting film 81 to the first anode drive electrode 21 through the first anode, so that the first light-emitting film 81 is electrically connected to the first anode drive electrode 21 through the first anode, and the first light-emitting film 81 covers the first anode drive electrode 21, the second anode drive electrode 22, the third anode drive electrode 23 and the cathode drive electrode 24, as shown in Figure 2b.
[0100] Step 103: forming a first light-emitting layer.
[0101] In an exemplary embodiment, forming the first light-emitting layer may include: on the substrate on which the aforementioned pattern is formed, patterning the first light-emitting film through a patterning process, so that the first light-emitting film forms a 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 drive electrode 21 on the substrate, and the orthographic projections of the first light-emitting layer 31 on the substrate do not overlap with the orthographic projections of the second anode drive electrode 22, the third anode drive electrode 23 and the cathode drive electrode 24 on the substrate, and the first light-emitting layer 31 is connected to the first anode drive electrode 21 through the first anode, as shown in Figure 2c.
[0102] Step 104: forming a first inorganic dielectric layer.
[0103] In an exemplary embodiment, forming the first inorganic dielectric layer may include: on the substrate on which the aforementioned pattern is formed, forming a first inorganic dielectric layer 11 covering the second anode drive electrode 22, the third anode drive electrode 23 and the cathode drive electrode 24 on the substrate, the first inorganic dielectric layer 11 and the first light-emitting layer 31 are arranged on the same layer, and the orthographic projections of the first inorganic dielectric layer 11 and the first light-emitting layer 31 on the substrate do not overlap, and a first hole is formed in the first inorganic dielectric layer 11 exposing the second anode drive electrode 22, the third anode drive electrode 23 and the cathode drive electrode 24, as shown in Figure 2d.
[0104] Step 105: forming a first conductive layer.
[0105] In an exemplary embodiment, forming the first conductive layer may include: forming a 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 covering the orthographic projection of the first light-emitting layer 31 and the cathode drive electrode 24 on the substrate, the orthographic projection of the first conductive layer 41 on the substrate does not overlap with the orthographic projection of the second anode drive electrode 22 and the third anode drive electrode 23 on the substrate, at least a portion of the first conductive layer 41 is in direct contact with the first light-emitting layer 31, and at least a portion of the first conductive layer 41 covers the cathode drive electrode 24 exposed by the first hole, as shown in Figure 2e.
[0106] Step 106: forming a second inorganic dielectric layer.
[0107] In an exemplary embodiment, forming the second inorganic dielectric layer may include: on the substrate on which the aforementioned pattern is formed, forming a second inorganic dielectric layer 12 on the first conductive layer, the second inorganic dielectric layer 12 covering the first conductive layer, the second anode drive electrode 22 and the third anode drive electrode 23, and a second hole exposing the second anode drive electrode 22, the third anode drive electrode 23 and the cathode drive electrode 24 is formed in the second inorganic dielectric layer 12, as shown in Figure 2f.
[0108] Step 107: forming a second light-emitting layer and a third inorganic medium layer.
[0109] In an exemplary embodiment, forming the second light-emitting layer and the third inorganic dielectric layer may include: on the substrate formed with the aforementioned pattern, first bonding the second light-emitting film to the second anode drive electrode through the second anode, so that the second light-emitting film is electrically connected to the second anode drive electrode through the second anode; then, patterning the second light-emitting film through a patterning process, so that the second light-emitting film forms a 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 drive electrode and the second anode drive electrode on the substrate, and the orthographic projections of the second light-emitting layer 32 on the substrate are all aligned with the third The orthographic projections of the anode drive electrode 23 and the cathode drive electrode 24 on the substrate do not overlap, and the second light-emitting layer 32 is connected to the second anode drive electrode through the second anode; subsequently, a third inorganic dielectric layer 13 covering the third anode drive electrode 23 and the cathode drive electrode 24 is formed on the second inorganic dielectric layer, and the third inorganic dielectric layer 13 is arranged on the same layer as the second light-emitting layer 32, and the orthographic projections of the third inorganic dielectric layer 13 and the second light-emitting layer 32 on the substrate do not overlap, and a third hole exposing the third anode drive electrode 23 and the cathode drive electrode 24 is formed in the third inorganic dielectric layer 13, as shown in Figure 2g.
[0110] Step 108: forming a second conductive layer.
[0111] In an exemplary embodiment, forming the second conductive layer may include: forming a second conductive layer 42 on the second light-emitting layer 32 on the substrate on which the aforementioned pattern is formed, the orthographic projections of the second conductive layer 42 on the substrate overlapping with the orthographic projections of the second light-emitting layer 32 and the cathode drive electrode 24 on the substrate, the orthographic projection of the second conductive layer 42 on the substrate not overlapping with the orthographic projection of the third anode drive electrode 23 on the substrate, at least a portion of the second conductive layer 42 directly contacting the second light-emitting layer 32, and at least a portion of the second conductive layer 42 covering the cathode drive electrode 24 exposed by the third hole, as shown in FIG2h.
[0112] Step 109: forming a fourth inorganic dielectric layer.
[0113] In an exemplary embodiment, forming the fourth inorganic dielectric layer may include: on the substrate on which the aforementioned pattern is formed, forming a fourth inorganic dielectric layer 14 on the second conductive layer, the fourth inorganic dielectric layer 14 covering the second conductive layer, the first anode drive electrode, the second anode drive electrode, the third anode drive electrode and the cathode drive electrode, and a fourth hole exposing the third anode drive electrode 23 and the cathode drive electrode 24 is formed in the fourth inorganic dielectric layer 14, as shown in Figure 2i.
[0114] Step 110: forming a third light-emitting layer and a fifth inorganic medium layer.
[0115] In an exemplary embodiment, forming the third light-emitting layer and the fifth inorganic dielectric layer may include: forming a third light-emitting layer 33 on the fourth inorganic dielectric layer 14 on the substrate on which the aforementioned pattern is formed, the third light-emitting layer 33 being connected to the third anode drive electrode through the third anode; the orthographic projection of the third light-emitting layer 33 on the substrate covers the orthographic projections of the first anode drive electrode, the second anode drive electrode and the third anode drive electrode on the substrate, and the orthographic projections of the third light-emitting layer 33 on the substrate do not overlap with the orthographic projections of the cathode drive electrode 24 on the substrate; subsequently, forming a fifth inorganic dielectric layer 15 covering the cathode drive electrode 24 on the fourth inorganic dielectric layer 14, the fifth inorganic dielectric layer 15 being arranged on the same layer as the third light-emitting layer 33, and the orthographic projections of the fifth inorganic dielectric layer 15 and the third light-emitting layer 33 on the substrate do not overlap, and a fifth hole exposing the cathode drive electrode 24 is formed in the fifth inorganic dielectric layer 15, as shown in Figure 2j.
[0116] Step 111: forming a third conductive layer.
[0117] In an exemplary embodiment, forming the third conductive layer may include: on the substrate forming the aforementioned pattern, forming a third conductive layer 43 on the third light-emitting layer 33, the orthographic projections of the third conductive layer 43 on the substrate overlap with the orthographic projections of the second light-emitting layer, the first light-emitting layer and the cathode drive electrode 24 on the substrate, at least part of the third conductive layer 43 is in direct contact with the third light-emitting layer 33, and at least part of the third conductive layer 43 covers the cathode drive electrode 24 exposed by the fifth hole, as shown in Figure 2k.
[0118] FIG3 is a schematic diagram of the cross-sectional structure of another light-emitting substrate according to an exemplary embodiment of the present disclosure. In an exemplary embodiment, as shown in FIG3 , the main structure of the light-emitting substrate according to the embodiment of the present disclosure is substantially the same as the main structure of the light-emitting substrate shown in FIG1 , except that the light-emitting substrate further includes a non-sub-pixel region 200 disposed on at least one side of the sub-pixel region 100, the cathode drive electrode 24 and the cathode 60 are both located in the non-sub-pixel region 200, at least a portion of the first conductive layer 41, at least a portion of the second conductive layer 42, and at least a portion of the third conductive layer 43 are located in the non-sub-pixel region 200, a first end of the cathode 60 is connected to the third conductive layer 43 located in the non-sub-pixel region 200, and a second end of the cathode 60 extends in a direction close to the drive backplane 101 and is connected to the cathode drive electrode 24.
[0119] In an exemplary embodiment, the cathode 60 is electrically connected to the first conductive layer 41 , the second conductive layer 42 and the third conductive layer 43 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 ring-shaped, and at least a portion of the cathode driving electrode 24 is disposed around the cathode 60 and directly contacts the sidewall of the cathode 60 .
[0121] In an exemplary embodiment, the light-emitting substrate of the disclosed embodiment further includes a strapping electrode 70 disposed in the sub-pixel region 100 , the strapping electrode 70 extending in a direction perpendicular to the light-emitting substrate, and the strapping electrode 70 electrically connects the first conductive layer 41 , the second conductive layer 42 and the third conductive layer 43 located in the sub-pixel region 100 .
[0122] FIG4 is a schematic diagram of the cross-sectional structure of another light-emitting substrate according to an exemplary embodiment of the present disclosure. In an exemplary embodiment, as shown in FIG4 , the main structure of the light-emitting substrate according to the embodiment of the present disclosure is substantially the same as the main structure of the light-emitting substrate shown in FIG1 , except that the second light-emitting layer 32 is bonded to the first light-emitting layer 31 via the first conductive layer 41, and the side of the first conductive layer 41 close to the driving backplane 101 is in direct contact with the first light-emitting layer 31, while the side of the first conductive layer 41 away from the driving backplane 101 is in direct contact with the second light-emitting layer 32; the third light-emitting layer 33 is bonded to the second light-emitting layer 32 via the second conductive layer 42, and the side of the second conductive layer 42 close to the driving backplane 101 is in direct contact with the second light-emitting layer 32, while the side of the second conductive layer 42 away from the driving backplane 101 is in direct contact with the third light-emitting layer 33.
[0123] In the exemplary embodiment, the second light-emitting layer 32 is bonded to the first light-emitting layer 31 via the first conductive layer 41, and the third light-emitting layer 33 is bonded to the second light-emitting layer 32 via the second conductive layer 42, forming a series light-emitting layer group. The series light-emitting layer group shares a common anode 50 and a common cathode 60. The first light-emitting layer 31 on the side of the series light-emitting layer group close to the driving backplane 101 is connected to the anode driving electrode 20 via the common anode 50, and the third conductive layer 43 on the side of the series light-emitting layer group away from the driving backplane 101 is connected to the cathode driving electrode 24 via the common cathode 60. The light-emitting layers in the series light-emitting layer group share a common anode 50 and a common cathode 60.
[0124] In an exemplary embodiment, the orthographic projections of 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 on the driving backplane 101 completely overlap.
[0125] In an exemplary embodiment, the first conductive layer 41 , the second conductive layer 42 , and the third conductive layer 43 each include a metal oxide, for example, indium tin oxide or indium zinc oxide.
[0126] FIG5 is a schematic diagram of the cross-sectional structure of another light-emitting substrate according to an exemplary embodiment of the present disclosure. In an exemplary embodiment, as shown in FIG5 , the main structure of the light-emitting substrate according to the embodiment of the present disclosure is substantially the same as the main structure of the light-emitting substrate shown in FIG1 , except that the first light-emitting layer 31 is connected to a first anode 51 and a first cathode 61, respectively; the second light-emitting layer 32 is arranged on a 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 overlaps the orthographic projection of the first light-emitting layer 31 on the driving backplane 101, and the second light-emitting layer 32 is connected to a second anode 52 and a second cathode 62, respectively; the third light-emitting layer 33 is arranged on a 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 overlaps the orthographic projection of the second light-emitting layer 32 on the driving backplane 101, and the third light-emitting layer 33 is connected to a third anode 53 and a third cathode 63, respectively.
[0127] The present disclosure also provides a method for preparing a light-emitting substrate, comprising:
[0128] At least two light-emitting layers are sequentially arranged on the driving backplane, and the at least two light-emitting layers are sequentially arranged 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 close to the driving backplane among 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 far from the driving backplane among adjacent light-emitting layers on the driving backplane.
[0129] The present disclosure also provides a display device including the light-emitting substrate of the aforementioned exemplary embodiment. The display device can be any product or component with a display function, such as a mobile phone, tablet computer, television, monitor, laptop computer, digital photo frame, or navigation system.
[0130] The drawings in this disclosure only relate to the structures involved in this disclosure, and other structures may refer to general designs. In the absence of conflict, the embodiments of this disclosure, that is, the features in the embodiments, may be combined with each other to obtain new embodiments.
[0131] It should be understood by those skilled in the art that the technical solutions of the present disclosure may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present disclosure, and all should be included in the scope of the claims of the present disclosure.
Claims
1. A light-emitting substrate, comprising at least one sub-pixel area, wherein the sub-pixel area comprises a driving backplane and at least two light-emitting devices arranged on the driving backplane, wherein the at least two light-emitting devices each comprise a light-emitting layer, and the light-emitting layers of the at least two light-emitting devices are arranged sequentially along the thickness direction of the driving backplane, and the orthographic projections of the light-emitting layers of the at least two light-emitting devices on the driving backplane overlap, and the orthographic projection area of the light-emitting layer of adjacent light-emitting layers close to the driving backplane on the driving backplane is less than or equal to the orthographic projection area of the light-emitting layer of adjacent light-emitting layers far from the driving backplane on the driving backplane.
2. The light-emitting substrate according to claim 1 comprises a first light-emitting layer, a second light-emitting layer and a third light-emitting layer arranged in sequence along a direction away from the driving backplane, the first light-emitting layer, the second light-emitting layer and the third light-emitting layer have overlapping orthographic projections on the driving backplane, 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 according to 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 according to 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 area, 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 area, 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 area.
5. The light-emitting substrate according to 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 includes an anode driving electrode, and the light emitting device also includes an anode. A first end of the anode is connected to the light emitting layer, and a second end of the anode is connected to the anode driving electrode.
7. The light-emitting substrate according to claim 6, wherein The driving backplane includes at least two anode driving electrodes. The light-emitting layers of adjacent light-emitting devices are insulated from each other, and the anodes of adjacent light-emitting devices are correspondingly connected to the at least two anode driving electrodes.
8. The light-emitting substrate according to claim 6, wherein The light-emitting layers of adjacent light-emitting devices are connected in series to form a light-emitting layer series group. The light-emitting layer series group shares a common anode. The light-emitting layers of the light-emitting layer series group close to the driving backplane are connected to the anode driving electrode through the common anode.
9. The light-emitting substrate according to any one of claims 1 to 5, wherein: The driving backplane includes a cathode driving electrode, and the light-emitting device also includes a conductive layer, which is arranged on the side of the light-emitting layer away from the driving backplane, and at least part of the conductive layer is in direct contact with the light-emitting layer. The light-emitting device also includes a cathode, and the conductive layer is connected to the cathode driving electrode through the cathode.
10. The light emitting substrate according to claim 9, wherein The conductive layers of the at least two light emitting devices share a cathode.
11. The light-emitting substrate according to claim 9, wherein The adjacent light-emitting layers are connected in series through the conductive layer to form a light-emitting layer series group. The light-emitting layer series group shares a cathode. The conductive layer of the light-emitting layer series group away from the driving backplane is connected to the cathode driving electrode through the shared cathode.
12. The light-emitting substrate according to claim 9, further comprising an inorganic dielectric layer, wherein a side of the inorganic dielectric layer close to the driving backplane is in direct contact with the conductive layer, and a side of the inorganic dielectric layer away from the driving backplane is in direct contact with the light-emitting layer.
13. The light-emitting substrate according to claim 9, wherein The cathode driving electrode is located in the sub-pixel area, or the light-emitting substrate further includes a non-sub-pixel area located 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 according to claim 9, wherein The cathode driving electrode is ring-shaped, and at least a portion of the cathode driving electrode is disposed around the cathode and directly contacts the side wall of the cathode.
15. A display device comprising the light-emitting substrate according to any one of claims 1 to 14.
16. A method for preparing a light-emitting substrate, comprising: At least two light-emitting layers are sequentially arranged on the driving backplane, and the at least two light-emitting layers are sequentially arranged 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 close to the driving backplane among 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 far from the driving backplane among adjacent light-emitting layers on the driving backplane.