Light-emitting device, preparation method thereof and display substrate

Abstract

The invention provides a light-emitting device and a preparation method thereof, and a display substrate, and relates to the technical field of display, the light-emitting device comprises a substrate, at least two epitaxial structures located at one side of the substrate, and at least one bonding layer; the bonding layer is located between the two adjacent epitaxial structures in the normal direction of the substrate and is used for fixing the two adjacent epitaxial structures together; wherein at least partial region of the bonding layer comprises a conductive part, and the conductive part is used for electrically connecting the two adjacent epitaxial structures together in the normal direction of the substrate. The light-emitting device is low in power consumption and good in display effect.

Description

Technical Field

[0001] The present application relates to the display field, and in particular to a light-emitting device and a preparation method thereof, and a display substrate. Background Art

[0002] With the rapid development of display technology, Mini LED (Mini Light Emitting Diode) and Micro LED (Micro Light Emitting Diode) display products have attracted widespread attention. However, the power consumption of the above two LED chips in the related technology is relatively high and it is difficult to further reduce it. Summary of the invention

[0003] The present application provides a light-emitting device and a preparation method thereof, and a display substrate. The light-emitting device has a simple structure and low power consumption.

[0004] The embodiments of the present application adopt the following technical solutions:

[0005] In a first aspect, an embodiment of the present application provides a light emitting device, the light emitting device comprising:

[0006] substrate;

[0007] at least two epitaxial structures located on one side of the substrate;

[0008] at least one bonding layer, the bonding layer being located between two adjacent epitaxial structures along the normal direction of the substrate and being used for fixing the two adjacent epitaxial structures together;

[0009] Wherein, at least a partial area of ​​the bonding layer includes a conductive portion, and the conductive portion is used to electrically connect two adjacent epitaxial structures along the normal direction of the substrate.

[0010] In some light-emitting devices provided in the embodiments of the present application, the light-emitting device comprises a first epitaxial structure, the bonding layer, and a second epitaxial structure sequentially arranged in a direction away from the substrate; an orthographic projection of the second epitaxial structure on the substrate is located within an orthographic projection of the first epitaxial structure on the substrate;

[0011] Wherein, the light emitting device further includes a protection portion, which surrounds and covers at least a portion of a side surface of the first epitaxial structure.

[0012] In some light-emitting devices provided in the embodiments of the present application, the bonding layer includes the conductive portion over the entire surface.

[0013] In some light-emitting devices provided in embodiments of the present application, the bonding layer includes a plurality of the conductive parts arranged at intervals, and at least one first light-transmitting part other than the conductive parts; the transmittance of the conductive parts is less than the transmittance of the first light-transmitting parts.

[0014] In some light-emitting devices provided in the embodiments of the present application, a plurality of the conductive parts disposed at intervals are arranged in an array, and the first light-transmitting parts are connected as a whole.

[0015] In some light-emitting devices provided in the embodiments of the present application, the conductive parts and the first light-transmitting parts are arranged alternately; wherein the planar graphics of the conductive parts and the first light-transmitting parts are both strips.

[0016] In some light-emitting devices provided in the embodiments of the present application, the light-emitting device further comprises a wire grid structure, and the wire grid structure is located on a side of the second epitaxial structure away from the substrate;

[0017] The wire grid structure includes a light-shielding portion and a second light-transmitting portion; wherein the orthographic projection of the light-shielding portion on the substrate overlaps with the orthographic projection of the conductive portion on the substrate, and the orthographic projection of the first light-transmitting portion on the substrate overlaps with the orthographic projection of the second light-transmitting portion on the substrate.

[0018] In a second aspect, an embodiment of the present application provides a display substrate comprising a plurality of light-emitting devices as described in any one of the first aspects.

[0019] In a third aspect, an embodiment of the present application provides a method for preparing a light-emitting device as described in any one of the first aspects, the method comprising:

[0020] forming a first epitaxial structure on a first substrate;

[0021] forming a second epitaxial structure on a second substrate;

[0022] A bonding layer is formed on a surface of the first epitaxial structure away from the first substrate, or a bonding layer is formed on a surface of the second epitaxial structure close to the second substrate; wherein at least a portion of the bonding layer includes a conductive portion, and the conductive portion is used to electrically connect two adjacent epitaxial structures along the normal direction of the substrate;

[0023] The first epitaxial structure and the second epitaxial structure are bonded together using a bonding layer.

[0024] In some methods for preparing light-emitting devices provided in embodiments of the present application, when a bonding layer is formed on a surface of the second epitaxial structure close to the second substrate, the step of forming a bonding layer on a surface of the second epitaxial structure close to the second substrate includes:

[0025] providing a third substrate;

[0026] bonding a surface of the second epitaxial structure away from the second substrate to the third substrate;

[0027] removing the second substrate;

[0028] A bonding layer is formed on a surface of the second epitaxial structure away from the third substrate.

[0029] In some methods for preparing light-emitting devices provided in embodiments of the present application, in the case where a bonding layer is formed on a surface of the first epitaxial structure away from the first substrate, after the step of forming the first epitaxial structure on the first substrate and before the step of forming a bonding layer on a surface of the first epitaxial structure away from the first substrate, the method further includes:

[0030] A protection portion is formed on a side surface of the first epitaxial structure.

[0031] In some methods for preparing light-emitting devices provided in embodiments of the present application, when a bonding layer is formed on a surface of the first epitaxial structure away from the first substrate, the bonding layer and the protective portion are formed simultaneously;

[0032] The step of simultaneously forming the bonding layer and the protection portion comprises:

[0033] A protection portion and a first light-transmitting portion are formed simultaneously; the protection portion covers the side surface of the first epitaxial structure, and the first light-transmitting portion is located on a surface of the first epitaxial structure away from the first substrate;

[0034] The conductive portion is formed, and the conductive portion is located on a surface of the first epitaxial structure away from the first substrate; wherein the bonding layer includes the conductive portion and the first light-transmitting portion.

[0035] Embodiments of the present application provide a light-emitting device and a method for preparing the same, and a display substrate. The light-emitting device includes a substrate, at least two epitaxial structures located on one side of the substrate, and at least one bonding layer; the bonding layer is located between two adjacent epitaxial structures along the normal direction of the substrate, and is used to fix the two adjacent epitaxial structures together; wherein at least a portion of the bonding layer includes a conductive portion, and the conductive portion is used to electrically connect the two adjacent epitaxial structures along the normal direction of the substrate together.

[0036] The present application provides a structure of a light-emitting device. Compared with the related art in which various epitaxial structures are connected in series on the plane of a substrate by means of conductive wire bridging, the light-emitting device provided by the present application connects in series at least two epitaxial structures in a normal direction perpendicular to the substrate through a bonding layer having a conductive portion. While ensuring the stability of the electrical performance of the light-emitting device, it reduces the design difficulty, reduces power consumption, and reduces the design space.

[0037] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0039] Figure 1 A schematic diagram of the structure of a light emitting device in a related art provided in an embodiment of the present application;

[0040] Figure 2-Figure 3 A schematic diagram of the structures of two light-emitting devices provided in the embodiments of the present application;

[0041] Figure 4A and Figure 4B A schematic diagram of the structures of two conductive parts provided in the embodiments of the present application;

[0042] Figure 5 to Figure 7 The following are structural schematic diagrams of three light-emitting devices provided in the embodiments of the present application;

[0043] Figure 8 A comparison curve of the transmittance of the bonding layer doped with indium tin oxide nanoparticles of different concentrations provided in the embodiments of the present application;

[0044] Fig. 9 Figures (1) to (4) are schematic diagrams of top-view structures of four bonding layers;

[0045] Figure 10-11 The schematic diagrams of the structures of two light-emitting devices provided in the embodiments of the present application;

[0046] Fig.12 Figures (1) to (2) are schematic top-view structures of the other two bonding layers;

[0047] Figure 13A to Figure 15Structural schematic diagrams of four light-emitting devices provided in the embodiments of the present application;

[0048] Fig.16 A schematic structural diagram of a display substrate provided in an embodiment of the present application;

[0049] Fig.17 for Fig.16 A schematic diagram of the structure of the light emitting device;

[0050] Fig.18 Figures (1) to (6) are schematic diagrams of intermediate structures in the process of forming a bonding layer on the second epitaxial structure;

[0051] Fig.19 Figures (1) to (8) are schematic diagrams of intermediate structures in the process of forming a bonding layer on the first epitaxial structure;

[0052] Fig. 20 Figures (1) to (2) are schematic diagrams of intermediate structures of a preparation process for forming a protective portion using an etching process;

[0053] Fig.21 Figures (1) to (4) are schematic diagrams of intermediate structures of another preparation process of forming a protective portion using a nanoimprint process;

[0054] Fig. 22 Figures (1) to (4) are schematic diagrams of intermediate structures in a preparation process for forming a wire grid structure. DETAILED DESCRIPTION

[0055] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0056] In the drawings, the thickness of regions and layers may be exaggerated for clarity. The same reference numerals in the drawings represent the same or similar structures, and thus their detailed descriptions will be omitted. In addition, the drawings are only schematic illustrations of the present application and are not necessarily drawn to scale.

[0057] Unless the context requires otherwise, throughout the specification and claims, the term "including" is to be interpreted as an open, inclusive meaning, that is, "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example" or "some examples" and the like are intended to indicate that specific features, structures, materials or characteristics associated with the embodiment or example are included in at least one embodiment or example of the present application. The schematic representation of the above terms does not necessarily refer to the same embodiment or example. In addition, the specific features, structures, materials or characteristics may be included in any one or more embodiments or examples in any appropriate manner.

[0058] In the embodiments of the present application, words such as "first" and "second" are used to indicate parts of identical or similar items having substantially the same functions and effects. This is only for the purpose of clearly describing the technical solutions of the embodiments of the present application and shall not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features.

[0059] The features such as "parallel", "perpendicular" and "same" used in the embodiments of the present application include the features such as "parallel", "perpendicular", "same" in the strict sense, as well as the cases where "approximately parallel", "approximately perpendicular", "approximately the same" and the like contain certain errors, taking into account the errors associated with the measurement of the specific quantity (e.g., the limitations of the measurement system), and are expressed within the acceptable deviation range for the specific value determined by ordinary technicians in the field. For example, "approximately" can mean within one or more standard deviations, or within 10% or 5% of the value. "At least one" means one or more, and "a plurality" means at least two.

[0060] The "same layer" in the embodiments of the present application refers to the relationship between multiple film layers formed by the same material after the same step (e.g., a one-step patterning process). The "same layer" here does not always mean that the thickness of multiple film layers is the same or the height of multiple film layers in the cross-sectional view is the same. The polygons in this specification are not strictly defined, and can be approximate triangles, parallelograms, trapezoids, pentagons or hexagons, etc., and there may be some small deformations caused by tolerances.

[0061] In this specification, "electrically connected" and "coupled" include the situation where the components are connected together through an element having some electrical function. There is no particular limitation on the "element having some electrical function" as long as it can transmit and receive 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 elements having various functions.

[0062] With the rapid development of display technology, Mini LED (Mini Light Emitting Diode) and Micro LED (Micro Light Emitting Diode) display products have attracted widespread attention. However, in the related art, when the above two types of LED chips are driven by transistor driving circuits, the power consumption of the overall display substrate is relatively high.

[0063] In order to reduce the power consumption of the display substrate, a solution of a high-voltage light-emitting device is provided in the related art, for example Figure 1 As shown, a plurality of epitaxial structures (for example, the epitaxial structure includes an N-type semiconductor layer 108, a quantum well layer 107, and a P-type semiconductor layer 106) are sequentially arranged on the substrate 100 along a first direction, and at least two adjacent epitaxial structures are connected in series, for example, Figure 1 As shown, the P-type semiconductor layer 106 in the first epitaxial structure is electrically connected to the first electrode 101 through the diffusion layer 102, the side of the epitaxial structure is covered with a passivation layer 103, and the passivation layer 103 is provided with an opening, and the conductive electrode 104 electrically connects the N-type semiconductor layer 108 in the first epitaxial structure to the diffusion layer 102 on the second epitaxial structure through the opening, and the N-type semiconductor layer 108 in the last epitaxial structure is electrically connected to the second electrode 105. The preparation process of the device is complicated, the process difficulty is high, and the yield is low. In addition, the horizontal series setting method occupies more space and is not suitable for the application of small-sized light-emitting device products.

[0064] In addition, in the related art, a plurality of epitaxial structures are stacked in sequence along the vertical direction and bonded by indium tin oxide to prepare a high-voltage light-emitting device; however, the yield is low and the process is very difficult.

[0065] Based on this, an embodiment of the present application provides a light-emitting device and a preparation method thereof, and a display substrate. The light-emitting device includes a substrate, at least two epitaxial structures located on one side of the substrate, and at least one bonding layer; the bonding layer is located between two adjacent epitaxial structures along the normal direction of the substrate, and is used to fix the two adjacent epitaxial structures together; wherein at least a partial area of ​​the bonding layer includes a conductive portion, and the conductive portion is used to electrically connect the two adjacent epitaxial structures along the normal direction of the substrate together.

[0066] The present application provides a structure of a high-voltage light-emitting device, which connects at least two epitaxial structures in series along a normal direction perpendicular to a substrate through a bonding layer having a conductive portion, thereby ensuring stable electrical performance of the light-emitting device while reducing design difficulty, power consumption, and design space.

[0067] The light-emitting device and its preparation method, and the display substrate provided in the embodiments of the present application will be specifically introduced and described below with reference to the accompanying drawings.

[0068] The embodiment of the present application provides a light emitting device, such as Figure 2 , Figure 3 or Fig.15 As shown, the light emitting device comprises:

[0069] Substrate 1;

[0070] At least two epitaxial structures (e.g., epitaxial structure 2 and epitaxial structure 3) located on one side of substrate 1;

[0071] At least one bonding layer 4, the bonding layer 4 is located between two adjacent epitaxial structures (for example, epitaxial structure 2 and epitaxial structure 3) along the normal direction of the substrate 1, and is used to fix the two adjacent epitaxial structures (for example, epitaxial structure 2 and epitaxial structure 3) together;

[0072] At least a partial area of ​​the bonding layer 4 includes a conductive portion 41 , and the conductive portion 41 is used to electrically connect two adjacent epitaxial structures (eg, the epitaxial structure 2 and the epitaxial structure 3 ) along the normal direction of the substrate 1 .

[0073] The light emitting device provided in the embodiment of the present application may be a structure with a size reduced to the order of hundreds of microns. For example, the area of ​​the light emitting region of the light emitting device is preferably 1 mm 2 Below, more preferably 10000 μm 2 Below, more preferably 3000 μm 2 Below, more preferably 700 μm 2 Below, even below 200μm 2 the following.

[0074] There is no limitation on the specific material of the substrate 1. For example, the material of the substrate 1 may include one of glass, silicon, sapphire and polyimide.

[0075] In some embodiments, the light emitting device may not include the substrate 1. Specifically, the substrate 1 made of sapphire may be removed by laser lift-off; the substrate 1 made of silicon may be removed by wet etching or dry etching. Of course, in some embodiments, the light emitting device may include the substrate 1.

[0076] For example, Figure 2 or Figure 3 As shown, the epitaxial structure includes a first semiconductor layer 21 , a quantum well layer 22 (MQW) and a second semiconductor layer 23 which are sequentially arranged in a direction away from the substrate 1 .

[0077] In some examples, such as Figure 2 or Figure 3 As shown, the epitaxial structure may further include a buffer conductive layer 24 .

[0078] It should be noted that the buffer conductive layer 24 is used to improve the conduction stability between the first semiconductor layer 22 and the first electrode 25. Exemplarily, the material of the buffer conductive layer 24 may include indium tin oxide (ITO).

[0079] The first semiconductor layer 21 may be a P-type semiconductor layer, such as P-type gallium nitride (P-GaN), and the second semiconductor layer 23 may be an N-type semiconductor layer, such as N-type gallium nitride (N-GaN). Alternatively, the first semiconductor layer 21 may be an N-type semiconductor layer, such as N-type gallium nitride (N-GaN), and the second semiconductor layer 23 may be a P-type semiconductor layer, such as P-type gallium nitride (P-GaN).

[0080] Here, whether the thickness of the multiple quantum well layers (MQW) 22 in each light emitting device is the same is not limited. In some light emitting devices, the thickness of the quantum well layers (MQW) 22 in each epitaxial structure is not completely the same.

[0081] Exemplarily, the bonding layer 4 fixes two adjacent epitaxial structures (eg, epitaxial structure 2 and epitaxial structure 3 ) together through bonding.

[0082] It should be noted that at least a portion of the bonding layer 4 includes the conductive portion 41, which means:

[0083] The first case: Fig. 9 As shown in Figures (1) to (4), a partial area of ​​the bonding layer 4 includes a conductive portion 41;

[0084] The second case, such as Figures 2-3 , Figure 5 to Figure 7 As shown, the entire area of ​​the bonding layer 4 includes the conductive portion 41 .

[0085] It should be emphasized that the conductive part 41 includes a conductive material and a base material. It can be understood that after the conductive material is mixed in the base material, the base material as a whole has a conductive function.

[0086] For example, Figure 4A As shown, the conductive material in the conductive part 41 is micro-nano conductive particles (Nanoparticle); Figure 4B As shown, the conductive material in the conductive part 41 is a conductive wire segment (Nano Wire). Among them, the micro-nano conductive particles may include at least one of indium tin oxide micro-nano particles (ITO), indium zinc oxide micro-nano particles (IZO), conductive micro beads, and nano silver particles; the conductive wire segment may include at least one of nano silver wire and carbon nano tube.

[0087] Exemplarily, the base material in the conductive part 41 may be a glue material.

[0088] Since the base material of the conductive part 41 is glue, the conductive part 41 has the function of electrically connecting and fixing (bonding) two adjacent epitaxial structures (eg, epitaxial structure 2 and epitaxial structure 3 ) along the normal direction of the substrate 1 .

[0089] The present application provides a structure of a high-voltage light-emitting device, which connects at least two epitaxial structures in series along a normal direction perpendicular to a substrate 1 through a bonding layer 4 having a conductive portion 41, thereby reducing the design difficulty, reducing the process difficulty, improving the preparation yield, reducing power consumption, and reducing the design space while ensuring the stability of the electrical performance of the light-emitting device. Among them, the structure of the high-voltage light-emitting device is conducive to reducing the overall power consumption of the driving substrate.

[0090] In some light-emitting devices provided in the embodiments of the present application, such as Figure 5 to Figure 7 As shown, the light emitting device comprises a first epitaxial structure 2, a bonding layer 4 and a second epitaxial structure 3 which are sequentially arranged in a direction away from the substrate 1; the orthographic projection of the second epitaxial structure 3 on the substrate 1 is located within the orthographic projection of the first epitaxial structure 2 on the substrate 1;

[0091] The light emitting device further includes a protection portion 7 , which surrounds and covers at least a portion of the side surface of the first epitaxial structure 2 .

[0092] In an exemplary embodiment, the orthographic projection of the second epitaxial structure 3 on the substrate 1 is located within the orthographic projection of the first epitaxial structure 2 on the substrate 1 including the following situations:

[0093] The first one, such as Figure 5 to Figure 7 As shown, the outer contour of the orthographic projection of the second epitaxial structure 3 on the substrate 1 is located within the outer contour of the orthographic projection of the first epitaxial structure 2 on the substrate 1;

[0094] In the second type, the outer contour of the orthographic projection of the second epitaxial structure 3 on the substrate 1 is arranged flush with the outer contour of the orthographic projection of the first epitaxial structure 2 on the substrate 1 .

[0095] This specification uses the example that the outer contour of the orthographic projection of the second epitaxial structure 3 on the substrate 1 is located within the outer contour of the orthographic projection of the first epitaxial structure 2 on the substrate 1 for explanation.

[0096] In the case where the outer contour of the orthographic projection of the second epitaxial structure 3 on the substrate 1 is located within the outer contour of the orthographic projection of the first epitaxial structure 2 on the substrate 1, for example, Figure 2As shown, the area of ​​the first semiconductor layer 31 in the second epitaxial structure 3 is less than or equal to the area of ​​the second semiconductor layer 23 in the first epitaxial structure 2; for example, the area of ​​the first semiconductor layer 31 in the second epitaxial structure 3 is 10% to 90% of the area of ​​the second semiconductor layer 23 in the first epitaxial structure 2. Or, for example, Figure 2 As shown, the orthographic projection of the first semiconductor layer 31 in the second epitaxial structure 3 on the substrate 1 is located within the orthographic projection of the second semiconductor layer 23 in the first epitaxial structure 2 on the substrate 1. Or, for example, Figure 2 As shown, the orthographic projection of the first semiconductor layer 31 in the second epitaxial structure 3 on the substrate 1 is located within the orthographic projection of the buffer conductive layer 24 in the first epitaxial structure 2 on the substrate 1 .

[0097] The protection part 7 may be made of insulating material to prevent leakage due to conduction between semiconductor layers or between semiconductor layers and quantum well layers in the epitaxial structure at the bottom of the light-emitting device through the side or side regions.

[0098] The protection portion 7 surrounds and covers at least a portion of the side surface of the first epitaxial structure 2, which may include the following situations:

[0099] First, Figure 7 As shown, the protection portion 7 surrounds and covers a portion of the side surface of the first epitaxial structure 2;

[0100] Second, if Figure 5 or Figure 6 As shown, the protection portion 7 surrounds and covers the entire area of ​​the side surface of the first epitaxial structure 2 .

[0101] The light-emitting device provided in the embodiment of the present application is provided with a protective portion 7 surrounding and covering at least a partial area of ​​the side surface of the first epitaxial structure 2. In this way, during the preparation process of the light-emitting device, the conductive material is prevented from adhering to the side surface of the first epitaxial structure 2, thereby preventing the conductive material adhering to the side surface of the first epitaxial structure 2 from conducting between the semiconductor layers in the epitaxial structure at the bottom of the light-emitting device, or between the semiconductor layer and the quantum well layer, thereby preventing leakage.

[0102] In some light-emitting devices provided in the embodiments of the present application, such as Figure 2 , Figure 3 , Figure 5 to Figure 7 As shown, the bonding layer 4 includes a conductive portion 41 over the entire surface.

[0103] By setting the bonding layer 4 to include a full-surface conductive portion 41, the bonding layer 4 (conductive portion 41) can reduce the resistance between the two adjacent epitaxial structures (for example, epitaxial structure 2 and epitaxial structure 3) while bonding the two adjacent epitaxial structures (for example, epitaxial structure 2 and epitaxial structure 3) together, thereby improving the conduction effect between the two adjacent epitaxial structures (for example, epitaxial structure 2 and epitaxial structure 3).

[0104] Figure 8 In the case where the bonding layer 4 includes the conductive portion 41 on the entire surface, when the doping concentration of the conductive material in the conductive portion 41 is increased ( Figure 8 The direction indicated by the middle arrow is the direction of increasing doping concentration), and the light transmittance of different bonding layers 4 shows that as the doping concentration of the conductive material increases, the light transmittance of the bonding layer decreases, which may reduce the light efficiency of the light-emitting device.

[0105] Figure 8 When the thickness of the bonding layer 4 is about 3μm (3μm±0.5μm), the higher the doping concentration, the lower the transmittance under the full spectrum. The decrease in transmittance in this part is due to the increase in haze caused by scattering, which leads to a decrease in transmittance under the normal viewing angle. It can be seen that the transmittance in the short wavelength part decreases significantly. This is because the transmittance caused by the light absorbed by ITO itself decreases after the concentration of ITO particles increases.

[0106] In order to further take into account and improve the light efficiency of light-emitting devices, such as Fig. 9 As shown in (1) to (4) of the figures, in some light-emitting devices provided in the embodiments of the present application, the bonding layer 4 includes a plurality of conductive portions 41 arranged at intervals, and at least one first light-transmitting portion 42 other than the conductive portions 41; the transmittance of the conductive portion 41 is less than the transmittance of the first light-transmitting portion 42.

[0107] It should be noted that the conductive portion 41 has both the functions of conducting electricity and bonding and fixing.

[0108] In the embodiment of the present application, by providing a conductive portion 41 and a first light-transmitting portion 42, while the conductive portion 41 realizes the conductive and bonding functions, the first light-transmitting portion 42 can increase the transmittance of the bonding layer 4, thereby greatly improving the light efficiency of the light-emitting device.

[0109] Exemplarily, the material of the first light-transmitting portion 42 is an insulating light-transmitting material.

[0110] The insulating light-transmitting material may be an inorganic material, for example, at least one of silicon nitride, silicon oxide and silicon oxynitride.

[0111] Alternatively, the insulating light-transmitting material may be an organic material, for example, at least one of acrylic resin, polycarbonate, and polyimide.

[0112] Fig. 9 Figures (1) to (4) provide four schematic top views of the bonding layer 4. In some light-emitting devices provided in the embodiments of the present application, a plurality of conductive portions 41 are spaced apart and arranged in an array, and the first light-transmitting portions 42 other than the conductive portions 41 are connected as a whole.

[0113] exist Fig. 9 In Figures (1) to (4), the plurality of conductive portions 41 are discretely distributed and arranged in an array, wherein the planar patterns of the plurality of conductive portions 41 may include arcs, polygons, and patterns formed by a combination of polygons and arcs.

[0114] It should be noted that the figure formed by the combination of polygons and arcs may include a figure formed by splicing polygons and arcs; or a figure formed by digging out a part of the polygons and arcs.

[0115] The arc shape may include a circle and an ellipse, and the polygonal shape may include a quadrilateral (such as a rectangle, a parallelogram, a rhombus), a pentagon, a hexagon, and the like.

[0116] Fig.10 and Fig.11 The bonding layer in Fig. 9 Figure (1) is a schematic diagram of two cross-sectional structures along the M1M2 direction.

[0117] In some light-emitting devices provided in the embodiments of the present application, such as Fig.12 As shown in Figures (1) to (2), the conductive portions 41 and the first light-transmitting portions 42 are alternately arranged; wherein the plane shapes of the conductive portions 41 and the first light-transmitting portions 42 are both strip-shaped.

[0118] Fig.13A , Fig. 13B and Fig.14 The bonding layer in Fig.12 Figure (1) is a schematic diagram of three cross-sectional structures along the M3M4 direction.

[0119] like Fig.12 As shown in Figures (1) to (2), when the conductive part 41 and the first light-transmitting part 42 are alternately arranged, and the plane figures of the conductive part 41 and the first light-transmitting part 42 are both strip-shaped, the bonding layer 4 forms a grating structure. Since the first light-transmitting part 42 can transmit light, and the conductive part 41 can block light (with low light transmittance or even no light transmission), the grating structure formed by the conductive part 41 and the first light-transmitting part 42 can convert light into polarized light. Therefore, the light-emitting device can directly provide polarized light.

[0120] For example, when the nanoimprinting process is used, the plane size (eg, line width) of the first light-transmitting portion 42 may range from 10 nm to 100 nm, and the spacing between adjacent first light-transmitting portions 42 may range from 200 nm to 500 nm.

[0121] When the size of the light-emitting device is relatively large, for example, greater than or equal to 10 μm, an ICP process may be used for preparation. When the size of the light-emitting device is relatively small, a nanoimprinting process may be used for preparation.

[0122] It should be noted that the conductive portion 41 has both the functions of conducting electricity and bonding and fixing.

[0123] In the embodiment of the present application, the conductive part 41 and the first light-transmitting part 42 are alternately arranged, and while the conductive part 41 realizes the conductive and bonding functions, the first light-transmitting part 42 can increase the transmittance of the bonding layer 4, thereby greatly improving the light efficiency of the light-emitting device.

[0124] In some light-emitting devices provided in the embodiments of the present application, such as Fig.13A , Fig. 13B and Fig.14 As shown, the light emitting device further includes a wire grid structure 8, and the wire grid structure 8 is located on a side of the second epitaxial structure 3 away from the substrate 1;

[0125] The wire grid structure 8 includes a shading portion 81 and a second light-transmitting portion 82 , wherein the orthographic projection of the shading portion 81 on the substrate 1 overlaps with the orthographic projection of the conductive portion 41 on the substrate 1 , and the orthographic projection of the first light-transmitting portion 42 on the substrate 1 overlaps with the orthographic projection of the second light-transmitting portion 82 on the substrate 1 .

[0126] Exemplarily, the second light-transmitting portion 82 may be a hollow structure.

[0127] Exemplarily, the light shielding portion 81 may be made of metal, such as aluminum (Al).

[0128] Exemplarily, when the wire grid structure 8 is prepared by a nanoimprinting process, the planar dimension (e.g., line width) of the shading portion 81 can range from 10nm to 100nm, and the planar dimension of the second light-transmitting portion 82 (when the second light-transmitting portion 82 is a hollow structure, the planar dimension is the spacing between adjacent light-shielding portions 81) can range from 200nm to 500nm.

[0129] At this time, if Fig.13A , Fig. 13B and Fig.14 As shown, the bonding layer 4 converts the light emitted from the first epitaxial structure 2 into polarized light, and the wire grid structure 8 converts the light emitted from the second epitaxial structure 3 into polarized light.

[0130] The embodiments of the present application provide a high-voltage light-emitting device capable of providing polarized light. Compared with the high-voltage light-emitting device in the related art, it adds the function of emitting polarized light, can eliminate the process of attaching polarizers, shorten the process flow, reduce costs, and can also reduce the overall power consumption of the device.

[0131] In some light-emitting devices provided in the embodiments of the present application, such as Figure 2 , Figure 5 , Fig.10 , Fig.11 , Fig.13A and Fig.14 As shown, the light emitting device comprises a first epitaxial structure 2, a bonding layer 4, a second epitaxial structure 3 and a first electrode 5 which are sequentially arranged in a direction away from the substrate 1;

[0132] The orthographic projection of the first electrode 5 on the substrate 1 is located within the outer contour of the orthographic projection of the second epitaxial structure 3 on the substrate 1 .

[0133] In some light-emitting devices provided in the embodiments of the present application, such as Figure 3 , Figure 6 , Figure 7 ,and Fig. 13B As shown, the light emitting device further includes a second electrode 6 , which is electrically connected to the first semiconductor layer 21 in the first epitaxial structure 2 .

[0134] One of the first electrode 5 and the second electrode 6 is an anode, and the other is a cathode.

[0135] In an embodiment of the present application, a display substrate is provided, such as Fig.16 As shown, the display substrate includes a plurality of light emitting devices Q as described in any one of the above, and also includes a driving substrate 100 .

[0136] In an exemplary embodiment, a reflective portion F is provided on the display substrate, and a plurality of grooves L are provided on the reflective portion F. A cross-section of the groove L along a direction perpendicular to the driving substrate 100 is arc-shaped (for example, semicircular or semi-elliptical), and a reflective material is provided on the wall of the groove L. The light-emitting device Q is provided at the bottom of the groove L. When the light-emitting device Q emits light, the wall of the groove L reflects the emitted light and converges it together, thereby improving the light output efficiency of the display substrate.

[0137] Fig.17 A schematic diagram of the structure of a light emitting device Q in a display substrate is provided. Fig.16 In the embodiment, when the light emitting device Q and the driving substrate 100 are arranged together to form a display substrate, the substrate 1 in the light emitting device Q is removed, and the first electrode 5 thereof is directly electrically connected to the driving substrate 100 .

[0138] An embodiment of the present application provides a method for preparing a light-emitting device as described in any one of the first aspects, the method comprising:

[0139] S10, forming a first epitaxial structure on a first substrate;

[0140] like Fig.18 As shown in Figure (1), or, Fig.19 As shown in Figure (1), a first epitaxial structure 2 is formed on a first substrate 1;

[0141] S20, forming a second epitaxial structure on a second substrate;

[0142] like Fig.18 As shown in Figure (2), or, Fig.19 As shown in FIG. (4), a second epitaxial structure 3 is formed on the second substrate 10;

[0143] One of the first substrate and the second substrate is the substrate 1 of the light emitting device, and the other will be removed.

[0144] S30, such as Fig.19 As shown in FIG. (3), a bonding layer 4 is formed on the surface of the first epitaxial structure 2 away from the first substrate 1 (for example, an intermediate structure 40 of the bonding layer 4 is first formed), or, Fig.18 As shown in Figures (3) to (5), a bonding layer 4 is formed on the surface of the second epitaxial structure 3 close to the second substrate 10; wherein at least a portion of the bonding layer 4 includes a conductive portion 41, and the conductive portion 41 is used to electrically connect two adjacent epitaxial structures along the normal direction of the substrate 1;

[0145] S40, such as Fig.18 Figure (5) or Fig.19 As shown in FIG. 7 , the first epitaxial structure 2 and the second epitaxial structure 3 are bonded together using a bonding layer 4 .

[0146] The present application provides a structure of a high-voltage light-emitting device, which connects at least two epitaxial structures in series along a normal direction perpendicular to a substrate 1 through a bonding layer 4 having a conductive portion 41, thereby reducing the design difficulty, reducing the process difficulty, improving the preparation yield, reducing power consumption, and reducing the design space while ensuring the stability of the electrical performance of the light-emitting device. Among them, the structure of the high-voltage light-emitting device is conducive to reducing the overall power consumption of the driving substrate.

[0147] In some methods for preparing light-emitting devices provided in the embodiments of the present application, for example Fig.18 As shown, in the case where a bonding layer is formed on a surface of the second epitaxial structure close to the second substrate, the step of forming a bonding layer on a surface of the second epitaxial structure close to the second substrate includes:

[0148] S31, such as Fig.18 As shown in Figure (3), a third substrate 20 is provided;

[0149] S32, such as Fig.18 As shown in FIG. (3), the surface of the second epitaxial structure 3 away from the second substrate 10 is bonded to the third substrate 20; at this time, a temporary bonding adhesive can be used to bond the surface of the second epitaxial structure 3 away from the second substrate 10 to the third substrate 20;

[0150] S33, such as Fig.18 As shown in Figure (4), the second substrate 10 is removed;

[0151] After removing the second substrate 10, an ashing process is used to remove the temporary bonding adhesive;

[0152] S34, such as Fig.18 As shown in FIG. 4 , a bonding layer 4 is formed on a surface of the second epitaxial structure 3 away from the third substrate 20 .

[0153] In some methods for preparing light-emitting devices provided in the embodiments of the present application, for example Fig.19 As shown, in the case where the bonding layer 4 is formed on the surface of the first epitaxial structure 2 away from the first substrate 1, the step of forming the bonding layer 4 on the surface of the first epitaxial structure 2 away from the first substrate 1 includes:

[0154] S31, such as Fig.19 As shown in Figure (1), a first substrate 1 is provided;

[0155] S32, such as Fig.19 As shown in Figure (1), a first epitaxial structure 2 is formed on a first substrate 1;

[0156] S33, such as Fig.19 As shown in FIG. (3), a bonding film 40 is formed on the surface of the first epitaxial structure 2 away from the first substrate 1;

[0157] S34, such as Fig.19 As shown in Figure (5), a third substrate 20 is bonded to a side of the second epitaxial structure 3 away from the second substrate 10;

[0158] At this time, a temporary bonding adhesive may be used to bond the surface of the second epitaxial structure 3 away from the second substrate 10 to the third substrate 20;

[0159] S35, such as Fig.19 As shown in Figure (6), the second substrate 10 is removed;

[0160] S36, such as Fig.19 As shown in FIG. (7), the first epitaxial structure 2 and the second epitaxial structure 3 are bonded together via a bonding film 40;

[0161] S37 , patterning the bonding film 40 to obtain the bonding layer 4 , and removing the third substrate 20 .

[0162] After removing the third substrate 20 , the temporary bonding adhesive is removed by an ashing process.

[0163] In some methods for preparing light-emitting devices provided in the embodiments of the present application, for example Fig.19 As shown, in the case where a bonding layer 4 is formed on the surface of the first epitaxial structure 2 away from the first substrate 1, as shown in FIG. Fig.19 In FIG. (1), after the step of forming the first epitaxial structure 2 on the first substrate 1, and as shown in FIG. Fig.19 In the middle figure (3), before the step of forming a bonding layer 4 on a surface of the first epitaxial structure 2 away from the first substrate 1, the method further comprises:

[0164] like Fig.19 As shown in FIG. 2 , a protection portion 7 is formed on the side surface of the first epitaxial structure 2 .

[0165] The protection part 7 may be made of insulating material to prevent leakage due to conduction between semiconductor layers or between semiconductor layers and quantum well layers in the epitaxial structure at the bottom of the light-emitting device through the side or side regions.

[0166] For Fig.19 The protection portion 7 shown in FIG. (2) can be formed by the following process steps:

[0167] Sub-step 1: forming a protective film on the surface of the first epitaxial structure 2, wherein the protective film covers the surface of the first epitaxial structure 2 away from the substrate 1 and the side surfaces of the first epitaxial structure 2;

[0168] Sub-step 2: using a patterning process, remove the portion of the protective film covering the surface of the first epitaxial structure 2 away from the substrate 1, and retain the side portion of the first epitaxial structure 2, to obtain Fig.19 The protection part 7 shown in Figure (2) is shown in Figure.

[0169] In some methods for preparing light-emitting devices provided in the embodiments of the present application, when a bonding layer is formed on a surface of the first epitaxial structure away from the first substrate, such as Fig. 20 or Fig.21 As shown, the bonding layer 4 and the protection portion 7 are formed simultaneously;

[0170] Fig. 20 A method for simultaneously forming a bonding layer 4 and a protective portion 7 by an ICP (Inductively Coupled Plasma, abbreviated as ICP) etching process is provided. Fig.21 A method for simultaneously forming a bonding layer 4 and a protective portion 7 using a nanoimprint process is provided.

[0171] The step of simultaneously forming the bonding layer 4 and the protection portion 7 includes:

[0172] Sub-step 1: Fig. 20 As shown in Figure (1) or as Fig.21 As shown in FIG. (3), a protection portion 7 and a first light-transmitting portion 42 are formed simultaneously; wherein the protection portion 7 covers the side surface of the first epitaxial structure 2, and the first light-transmitting portion 42 is located on the surface of the first epitaxial structure 2 away from the first substrate 1;

[0173] Sub-step 2: Fig. 20 As shown in Figure (2) or as Fig.21 As shown in FIG. (4), a conductive portion 42 is formed, and the conductive portion 42 is located on the surface of the first epitaxial structure 2 away from the first substrate 1; wherein the bonding layer 4 includes a conductive portion 41 and a first light-transmitting portion 42.

[0174] It should be noted that in Fig. 20 (2) Figure and Fig.21 In the structure shown in Figure (4), Fig.19 The steps in Figure (3) are similar, and a bonding film 40 is formed. The bonding film 40 needs to be patterned later to remove part of the bonding film on the side of the protection part 7 away from the first epitaxial structure 2, thereby obtaining a conductive part 41 and a first light-transmitting part 42 that are spaced apart.

[0175] Among them, when using ICP (Inductively Coupled Plasma, abbreviated ICP) etching process, such as Fig. 20 As shown in FIG. (1), a PVX film is formed on the first epitaxial structure 2 and patterned to obtain a protective portion 7 disposed on the side of the first epitaxial structure 2 and a first light-transmitting portion 42 disposed on the surface of the first epitaxial structure 2.

[0176] Among them, when the nanoimprinting process is used, Fig.21 As shown in FIG. (1), a protective portion 7 and a light-transmitting film (eg, a PVX film) are simultaneously formed on the first epitaxial structure 2; Fig.21 As shown in FIG. (2), a first mask pattern PR1 is used for nanoimprinting, wherein the first mask pattern PR1 is a mask plate for nanoimprinting; Fig.21 As shown in FIG. (3), the PVX film is etched to obtain a protection portion 7 disposed on the side of the first epitaxial structure 2 and a first light-transmitting portion 42 disposed on the surface of the first epitaxial structure 2.

[0177] For example, when the nanoimprinting process is used, the plane size (eg, line width) of the first light-transmitting portion 42 may range from 10 nm to 100 nm, and the spacing between adjacent first light-transmitting portions 42 may range from 200 nm to 500 nm.

[0178] When the size of the light-emitting device is relatively large, for example, greater than or equal to 10 μm, an ICP process may be used for preparation. When the size of the light-emitting device is relatively small, a nanoimprinting process may be used for preparation.

[0179] In addition, for a light emitting device having a wire grid structure 8 (WGP), such as Fig. 22 As shown, the wire grid structure 8 can be further prepared by a nano-imprinting process, wherein the wire grid structure 8 includes a light shielding portion 81 and a second light transmitting portion 82;

[0180] Specifically, the first step is Fig. 22 As shown in FIG. (1), a light shielding film 80 is formed on the second epitaxial structure 3; in the second step, a second mask film PR2 is formed on the light shielding film 80; in the third step, Fig. 22 As shown in FIG. (2), the second mask film is patterned to obtain a second mask pattern PR3; Step 4: Fig. 22 As shown in FIG. (3), the second mask pattern PR3 is used as a mask, and a nanoimprint process is used for imprinting, and an etching process is performed to form a light shielding portion 81 and a second light transmitting portion 82 (in this case, the second light transmitting portion 82 is a hollow structure);

[0181] In the nano-imprint process, the mask patterns (eg, PR1, PR2, and PR3) may be nano-imprint glue.

[0182] Furthermore, etching is performed on a local area of ​​the wire grid structure 8 to reserve a position for the first electrode 5, such as Fig. 22 As shown in FIG. (4), a first electrode 5 is formed. At this time, the first electrode 5 and the wire grid structure 8 are arranged in the same layer.

[0183] This specification only introduces the structure and preparation process related to the invention point of the light-emitting device. The light-emitting device may also include other film layers and structures, and the preparation method may also include other processes and steps. For details, please refer to the introduction in the relevant technology, which will not be repeated here.

[0184] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A light emitting device, characterized in that: The light emitting device comprises: substrate; at least two epitaxial structures located on one side of the substrate; at least one bonding layer, the bonding layer being located between two adjacent epitaxial structures along the normal direction of the substrate and being used for fixing the two adjacent epitaxial structures together; Wherein, at least a partial area of ​​the bonding layer includes a conductive portion, and the conductive portion is used to electrically connect two adjacent epitaxial structures along the normal direction of the substrate.

2. The light emitting device according to claim 1, characterized in that: The light emitting device comprises a first epitaxial structure, the bonding layer and a second epitaxial structure which are sequentially arranged in a direction away from the substrate; The orthographic projection of the second epitaxial structure on the substrate is located within the orthographic projection of the first epitaxial structure on the substrate; Wherein, the light emitting device further includes a protection portion, which surrounds and covers at least a portion of a side surface of the first epitaxial structure.

3. The light emitting device according to claim 2, characterized in that: The bonding layer includes the conductive portion over the entire surface.

4. The light emitting device according to claim 2, characterized in that: The bonding layer includes a plurality of the conductive parts arranged at intervals, and at least one first light-transmitting part other than the conductive parts; the light transmittance of the conductive part is smaller than the light transmittance of the first light-transmitting part.

5. The light emitting device according to claim 4, characterized in that: A plurality of the conductive parts are arranged in an array at intervals, and the first light-transmitting parts are connected as a whole.

6. The light emitting device according to claim 4, characterized in that: The conductive parts and the first light-transmitting parts are arranged alternately; wherein the plane figures of the conductive parts and the first light-transmitting parts are both strips.

7. The light emitting device according to claim 6, characterized in that: The light emitting device further comprises a wire grid structure, wherein the wire grid structure is located on a side of the second epitaxial structure away from the substrate; The wire grid structure includes a light-shielding portion and a second light-transmitting portion; wherein the orthographic projection of the light-shielding portion on the substrate overlaps with the orthographic projection of the conductive portion on the substrate, and the orthographic projection of the first light-transmitting portion on the substrate overlaps with the orthographic projection of the second light-transmitting portion on the substrate.

8. A display substrate comprising a plurality of light emitting devices according to any one of claims 1 to 7.

9. A method for preparing a light emitting device according to any one of claims 1 to 7, characterized in that: The method comprises: forming a first epitaxial structure on a first substrate; forming a second epitaxial structure on a second substrate; A bonding layer is formed on a surface of the first epitaxial structure away from the first substrate, or a bonding layer is formed on a surface of the second epitaxial structure close to the second substrate; wherein at least a portion of the bonding layer includes a conductive portion, and the conductive portion is used to electrically connect two adjacent epitaxial structures along the normal direction of the substrate; The first epitaxial structure and the second epitaxial structure are bonded together using a bonding layer.

10. The preparation method according to claim 9, characterized in that: In the case where a bonding layer is formed on a surface of the second epitaxial structure close to the second substrate, the step of forming a bonding layer on a surface of the second epitaxial structure close to the second substrate includes: providing a third substrate; bonding a surface of the second epitaxial structure away from the second substrate to the third substrate; removing the second substrate; A bonding layer is formed on a surface of the second epitaxial structure away from the third substrate.

11. The preparation method according to claim 9, characterized in that: In the case where a bonding layer is formed on a surface of the first epitaxial structure away from the first substrate, after the step of forming the first epitaxial structure on the first substrate and before the step of forming a bonding layer on a surface of the first epitaxial structure away from the first substrate, the method further includes: A protection portion is formed on a side surface of the first epitaxial structure.

12. The preparation method according to claim 9, characterized in that: In the case where a bonding layer is formed on a surface of the first epitaxial structure away from the first substrate, the bonding layer and the protective portion are formed simultaneously; The step of simultaneously forming the bonding layer and the protection portion comprises: A protection portion and a first light-transmitting portion are formed simultaneously; the protection portion covers the side surface of the first epitaxial structure, and the first light-transmitting portion is located on a surface of the first epitaxial structure away from the first substrate; The conductive portion is formed, and the conductive portion is located on a surface of the first epitaxial structure away from the first substrate; wherein the bonding layer includes the conductive portion and the first light-transmitting portion.

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