Light-emitting device and display panel

Abstract

The invention discloses a light-emitting device and a display panel. The light emitting device includes a first light emitting structure and a second light emitting structure grown directly over the first light emitting structure. The first light-emitting structure comprises a first semiconductor layer, a first light-emitting layer and a second semiconductor layer which are sequentially stacked. The second light-emitting structure comprises a third semiconductor layer, a second light-emitting layer and a fourth semiconductor layer which are sequentially stacked. The display panel comprises the light-emitting device. The second light-emitting structure is directly arranged on the first light-emitting structure, so that the arrangement of a bonding layer between the first light-emitting structure and the second light-emitting structure is reduced, and the light loss caused by the arrangement of the bonding layer is reduced. Moreover, the number of bonding process times is reduced due to the reduction of the arrangement of the bonding layer, thereby reducing the damage of the bonding process to the light-emitting device, and improving the quality and yield of the light-emitting device.

Description

Technical Field

[0001] The present application belongs to the field of display technology, and specifically relates to light-emitting devices and display panels. Background Art

[0002] In the colorized light emitting technology, the red, blue and green light emitting structures are bonded separately to form a light emitting device. This method usually requires at least three bonding processes. On the one hand, multiple bonding processes are likely to cause damage to the light emitting device, thereby affecting the quality and yield of the light emitting device; on the other hand, the bonding layer used for bonding is set on the light emitting surface of the light emitting structure, which is likely to cause light loss and reduce the light extraction efficiency.

[0003] Therefore, there is an urgent need for a new light-emitting device structure and display panel that can reduce the bonding layer to reduce light loss, and can reduce the number of bonding processes and reduce the damage to the light-emitting device caused by the bonding process, thereby improving the quality and yield of the light-emitting device. Summary of the invention

[0004] The purpose of the present application is to provide a light-emitting device and a display panel, which can reduce the bonding layer to reduce light loss, and can reduce the number of bonding processes and reduce the damage of the bonding process to the light-emitting device, thereby improving the quality and yield of the light-emitting device.

[0005] To solve the above technical problems, the present application provides a light-emitting device including a first light-emitting structure and a second light-emitting structure directly grown on the first light-emitting structure, wherein the first light-emitting structure includes a first semiconductor layer, a first light-emitting layer, and a second semiconductor layer stacked in sequence, and the second light-emitting structure includes a third semiconductor layer, a second light-emitting layer, and a fourth semiconductor layer stacked in sequence.

[0006] In the first light emitting structure, the first semiconductor layer is one of a hole type semiconductor layer or an electron type semiconductor layer, and the second semiconductor layer is the other of the hole type semiconductor layer or the electron type semiconductor layer. In the second light emitting structure, the third semiconductor layer is one of a hole type semiconductor layer or an electron type semiconductor layer, and the fourth semiconductor layer is the other of the hole type semiconductor layer or the electron type semiconductor layer.

[0007] In one embodiment, the second semiconductor layer and the third semiconductor layer are the same semiconductor layer. The fourth semiconductor layer is of the same type as the first semiconductor layer.

[0008] In one embodiment, the light emitting device further comprises a third light emitting structure and a bonding layer, wherein the bonding layer is used to bond the third light emitting structure to the driving substrate.

[0009] The third light emitting structure includes the first semiconductor layer, a third light emitting layer and a fifth semiconductor layer. The third light emitting layer is arranged on a side of the first semiconductor layer away from the first light emitting layer. The fifth semiconductor layer is arranged on a side of the third light emitting layer away from the first semiconductor layer. The fifth semiconductor layer is of the same type as the second semiconductor layer. The third light emitting structure and the first light emitting structure share the first semiconductor layer.

[0010] In one embodiment, the light emitting device further comprises a third light emitting structure, a first bonding layer and a second bonding layer. The first bonding layer is used to bond the third light emitting structure to a driving substrate. The first light emitting structure is bonded to the third light emitting structure through the second bonding layer.

[0011] The third light emitting structure includes a fifth semiconductor layer, a third light emitting layer and a sixth semiconductor layer stacked in sequence. The fifth semiconductor layer is one of a hole-type semiconductor layer and an electron-type semiconductor layer, and the sixth semiconductor layer is the other of the hole-type semiconductor layer and the electron-type semiconductor layer.

[0012] In one embodiment, the second bonding layer is disposed on a side of the first semiconductor layer away from the first light-emitting layer, the second bonding layer includes a transparent conductive layer, and the first semiconductor layer and the sixth semiconductor layer are bonded and electrically connected via the transparent conductive layer.

[0013] In one embodiment, the second bonding layer further includes a reinforcement portion, and the bonding strength between the reinforcement portion and the sixth semiconductor layer is greater than the bonding strength between the transparent conductive layer and the sixth semiconductor layer.

[0014] A groove is formed on a side of the transparent conductive layer facing the third light emitting structure. The reinforcing part is arranged in the groove, and the reinforcing part is bonded to the sixth semiconductor layer.

[0015] In one embodiment, the second bonding layer further includes a reinforcement portion, and the bonding strength between the reinforcement portion and the sixth semiconductor layer is greater than the bonding strength between the transparent conductive layer and the sixth semiconductor layer.

[0016] A groove is formed on a side of the transparent conductive layer facing the third light emitting structure, and the reinforcing part is arranged in the groove.

[0017] The light emitting device further comprises an alignment layer. The material of the alignment layer is the same as that of the reinforcing part. The alignment layer is arranged on a side of the sixth semiconductor layer away from the third light emitting layer, and the alignment layer corresponds to the groove. The alignment layer is bonded to the reinforcing part.

[0018] In one embodiment, the refractive index of the sixth semiconductor layer is greater than the refractive index of the transparent conductive layer, and the refractive index of the transparent conductive layer is greater than the refractive index of the reinforcement portion.

[0019] In one embodiment, in the orthographic projection of the plane where the first bonding layer is located, the area of ​​the third light-emitting layer is larger than that of the first light-emitting layer, and the area of ​​the first light-emitting layer is larger than that of the second light-emitting layer.

[0020] The third light-emitting layer is a red light-emitting layer, the first light-emitting layer is a green light-emitting layer, and the second light-emitting layer is a blue light-emitting layer.

[0021] The present application also provides a display panel, comprising any of the above-mentioned light-emitting devices and a driving substrate, wherein the light-emitting device is arranged on the driving substrate.

[0022] The light-emitting device provided in the embodiment of the present application comprises a first light-emitting structure and a second light-emitting structure directly grown on the first light-emitting structure. The first light-emitting structure comprises a first semiconductor layer, a first light-emitting layer, and a second semiconductor layer which are sequentially stacked. The second light-emitting structure comprises a third semiconductor layer, a second light-emitting layer, and a fourth semiconductor layer which are sequentially stacked. By directly setting the second light-emitting structure on the first light-emitting structure, the setting of the bonding layer between the first light-emitting structure and the second light-emitting structure is reduced, thereby reducing the light loss caused by the setting of the bonding layer. And since the setting of the bonding layer is reduced, the number of bonding processes is reduced, thereby reducing the damage to the light-emitting device caused by the bonding process, thereby improving the quality and yield of the light-emitting device. The display panel provided in the embodiment of the present application comprises the above-mentioned light-emitting device. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, 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 invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 This is a schematic diagram of the first structure of the light-emitting device provided in the embodiment of the present application;

[0025] Figure 2 yes Figure 1 A schematic top view of the structure of the second bonding layer of the light-emitting device;

[0026] Figure 3 is a schematic diagram of a second structure of a light-emitting device provided in an embodiment of the present application;

[0027] Figure 4 yes Figure 3A schematic diagram of a top view structure of a light emitting device;

[0028] Figure 5 This is a third structural schematic diagram of the light-emitting device provided in the embodiment of the present application;

[0029] Figure 6 is a fourth structural schematic diagram of a light-emitting device provided in an embodiment of the present application;

[0030] Figure 7 is a schematic diagram of the structure of a display panel provided in an embodiment of the present application;

[0031] Figure 8 The preparation includes Figure 3 A flow chart of a display panel including a light emitting device;

[0032] Fig. 9 yes Figure 8 The structural diagram of steps S1 to S3;

[0033] Fig.10 yes Figure 8 The structural diagram of step S4;

[0034] Fig.11 yes Figure 8 Schematic diagram of the structure of steps S5 to S6.

[0035] Reference numerals: display panel 1000; light emitting device 100; driving substrate 200;

[0036] A first light emitting structure 110; a second light emitting structure 120; a third light emitting structure 130; a bonding layer 140; a first bonding layer 141; a second bonding layer 142; a first electrode E1; a second electrode E2; and a third electrode E3;

[0037] The first semiconductor layer 111 , the first light-emitting layer 112 , the second semiconductor layer 113 , the third semiconductor layer 121 , the second light-emitting layer 122 , the fourth semiconductor layer 123 , the fifth semiconductor layer 131 , the third light-emitting layer 132 , the sixth semiconductor layer 133 , the alignment layer 134 , the transparent conductive layer 1421 , the reinforcement portion 1422 , the groove U , and the current diffusion layer D . DETAILED DESCRIPTION

[0038] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Based on the embodiments of the present invention, any modifications made by those skilled in the art without creative work are within the scope of protection of the present invention.

[0039] It should be noted that in the description of the present application, it should be understood that the orientations or positional relationships indicated by “up”, “down”, “front”, “back”, “left”, “right”, “inside”, “outside”, etc. are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0040] Please refer to Figure 1 , Figure 1 A schematic diagram of the first structure of the light-emitting device 100 provided in an embodiment of the present application. The light-emitting device 100 provided in an embodiment of the present application includes a first light-emitting structure 110 and a second light-emitting structure 120 directly grown on the first light-emitting structure 110. The first light-emitting structure 110 includes a first semiconductor layer 111, a first light-emitting layer 112, and a second semiconductor layer 113 stacked in sequence. The second light-emitting structure 120 includes stacked in sequence.

[0041] In the first light emitting structure 110, the first semiconductor layer 111 is one of a hole-type (P-type) semiconductor layer or an electron-type (N-type) semiconductor layer, and the second semiconductor layer 113 is the other of the hole-type semiconductor layer or the electron-type semiconductor layer. In the second light emitting structure 120, the third semiconductor layer 131 is one of the hole-type semiconductor layer or the electron-type semiconductor layer, and the fourth semiconductor layer 133 is the other of the hole-type semiconductor layer or the electron-type semiconductor layer. That is, the first semiconductor layer 111 is a hole-type semiconductor layer, the second semiconductor layer 113 is an electron-type semiconductor layer, the third semiconductor layer 121 is a hole-type semiconductor layer, and the fourth semiconductor layer 123 is an electron-type semiconductor layer. Alternatively, the first semiconductor layer 111 is an electron-type semiconductor layer, the second semiconductor layer 113 is a hole-type semiconductor layer, the third semiconductor layer 121 is a hole-type semiconductor layer, and the fourth semiconductor layer 123 is an electron-type semiconductor layer, and so on.

[0042] Optionally, the first light emitting structure 110, the second light emitting structure 120 and the third light emitting structure 130 are sub-millimeter light emitting diodes (Mini-LED) or micro light emitting diodes (Micro-LED). The light emitting device 100 is a Mini-LED chip or Micro-LED chip with a vertical structure, which is not limited in the present application.

[0043] In the embodiment of the present application, the second light emitting structure 120 is directly disposed on the first light emitting structure 110, thereby reducing the bonding layer between the first light emitting structure 110 and the second light emitting structure 120, thereby reducing the light loss caused by the bonding layer. In addition, since the bonding layer is reduced, the number of bonding processes is reduced, thereby reducing the damage to the light emitting device 100 caused by the bonding process, thereby improving the quality and yield of the light emitting device 100.

[0044] It should be noted that the direct growth of the present application refers to a method in which the first light-emitting structure 110 and the second light-emitting structure 120 are directly combined in the direction of the film layer stacking, and the bonding layer is omitted. That is, the first light-emitting structure 110 and the second light-emitting structure 120 are bonded together without using a bonding layer. Specifically, during the preparation process, the first light-emitting structure 110 is prepared on a substrate, and the second light-emitting structure 120 is directly grown on the film layer stacking direction of the first light-emitting structure 110, without the need to set up a separate substrate to form the second light-emitting structure 120. In other words, during the preparation process, the first light-emitting structure 110 is prepared on a substrate, and the second light-emitting structure 120 is coaxially grown in a direction perpendicular to the substrate, so that the first light-emitting structure 110 and the second light-emitting structure 120 are combined together.

[0045] In this embodiment, the light emitting device 100 further includes a third light emitting structure 130, a first bonding layer 141 and a second bonding layer 142. The first bonding layer 141 is used to bond the third light emitting structure 130 to the driving substrate, the first light emitting structure 110 is bonded to the third light emitting structure 130 through the second bonding layer 142, and the second light emitting structure 120 is located above the first light emitting structure 110.

[0046] The third light emitting structure 130 includes a fifth semiconductor layer 131, a third light emitting layer 132 and a sixth semiconductor layer 133 which are sequentially stacked. The fifth semiconductor layer 131 is a hole-type semiconductor layer or an electron-type semiconductor layer, and the sixth semiconductor layer 133 is the other of the hole-type semiconductor layer or the electron-type semiconductor layer.

[0047] The first light emitting structure 110, the second light emitting structure 120 and the third light emitting structure 130 can be bonded to the driving substrate by only two bonding steps, which reduces the number of bonding processes, simplifies the preparation process of the light emitting device 100 and the display panel 1000, and reduces the production cost and time.

[0048] In this embodiment, the second bonding layer 142 is disposed on a side of the first semiconductor layer 111 away from the first light-emitting layer 112. The second bonding layer 142 includes a transparent conductive layer 1421. The first semiconductor layer 111 and the sixth semiconductor layer 133 are bonded and electrically connected through the transparent conductive layer 1421. The first semiconductor layer 111 and the sixth semiconductor layer 133 are bonded through the transparent conductive layer 1421, so that the first light-emitting structure 110 is disposed on the light-emitting surface of the third light-emitting structure 130, and the light emitted by the third light-emitting structure 130 can be emitted through the transparent conductive layer 1421 to realize front light emission. Since the transparent conductive layer 1421 is conductive, the first semiconductor layer 111 and the sixth semiconductor layer 133 are electrically connected through the transparent conductive layer 1421, and then are connected to the driving substrate through a common electrode, which simplifies the connection structure and saves the manufacturing process.

[0049] Optionally, the second bonding layer 142 is 3-4 micrometers (μm). Specifically, the second bonding layer 142 is 3 μm, 3.2 μm, 3.5 μm, 3.8 μm or 4 μm.

[0050] The second bonding layer 142 further includes a reinforcing portion 1422. The bonding strength between the reinforcing portion 1422 and the sixth semiconductor layer 133 is greater than the bonding strength between the transparent conductive layer 1421 and the sixth semiconductor layer 133. Optionally, the material of the transparent conductive layer 1421 is indium tin oxide (ITO). The material of the reinforcing portion 1422 is silicon dioxide (SiO2), silicon oxynitride (SiO x N y ) or silicon nitride (Si N ) or a mixture of one or more thereof, which is not limited in the present application. In the present application, the material of the transparent conductive layer 1421 is indium tin oxide, and the material of the reinforcement part 1422 is silicon dioxide.

[0051] Bond strength refers to the strength of the chemical bonds in a material, measured in megapascals (MPa). Specifically, it refers to the strength of the bond between two atoms, that is, the maximum value that can resist tensile force. Taking ITO and silicon dioxide as an example, the bonding of silicon dioxide refers to the process of connecting two or more silicon dioxide molecules together through covalent bonds. In this process, each silicon dioxide molecule shares its four valence electrons to form a stable network structure. The silicon-oxygen bonds formed in the network structure are formed between highly electronegative oxygen atoms and low electronegative silicon atoms, which are very strong and stable. Silicon dioxide has a higher bond strength. The chemical bonds in the ITO bond are weaker than the silicon-oxygen bonds, so the bond strength of silicon dioxide is higher than that of ITO. Generally speaking, the higher the bond strength, the higher the strength and hardness of the material.

[0052] The present application calculates the bonding strength by measuring the surface energy of the bonding layer. The method for measuring the surface energy is the crack propagation diffusion method (blade insertion method). By inserting the blade into the bonding surface, an equation is established based on the principle that the elastic force of the separated part of the bonding layer and the bonding force at the crack top are balanced, thereby obtaining the average surface energy of the bonding layer. The bonding force is calculated based on the Young's modulus of the bonding layer, the thickness of the bonding layer, the blade thickness and the crack length, and the bonding strength is determined. Among them, the crack length is characterized and determined by an ultrasonic scanning microscope, and can also be determined by other methods. In this application, it is used to test the bonding strength between the bonding layer made of the material of the reinforcement portion 1422 and the sixth semiconductor layer 133, and the bonding strength between the bonding layer made of the material of the transparent conductive layer 1421 and the sixth semiconductor layer 133. During testing in the present application, the material of the sixth semiconductor layer 133 can be set on a bonding substrate, and the first light-emitting structure 110 and the second light-emitting structure 120 can be bonded to the bonding substrate through a bonding layer made of the material of the transparent conductive layer 1421 or the reinforcement part 1422 for testing.

[0053] Please refer to Figure 2 , a groove U is provided on one side of the transparent conductive layer 1421 facing the third light emitting structure 130. The reinforcement part 1422 is arranged in the groove U, and the reinforcement part 1422 is bonded to the sixth semiconductor layer 133. By setting the reinforcement part 1422 to bond to the sixth semiconductor layer 133, the bonding strength between the second bonding layer 142 and the third light emitting structure 130 is further increased. At the same time, where the groove U is not provided, the transparent conductive layer 1421 is in contact with and bonded to the sixth semiconductor layer 133, and the sixth semiconductor layer 133 is electrically connected to the first semiconductor layer 111. The light transmittance of the interface where the transparent conductive layer 1421 contacts the sixth semiconductor layer 133 is greater, and the light emitted by the third light emitting structure 130 can be emitted from the transparent conductive layer 1421, thereby improving the light extraction efficiency.

[0054] Optionally, the shape of the groove U is circular, and the shape of the reinforcement part 1422 is circular. The diameter of the groove U is 3 to 5 μm, which can be 3 μm, 3.5 μm, 4 μm, 4.5 μm or 5 μm, etc. The distance between the centers of the grooves U is 5 to 10 μm, which can be 5 μm, 6 μm, 7 μm, 8 μm, 9 μm or 10 μm, etc. The depth of the groove U is 1 to 2 μm, which can be 1 μm, 1.2 μm, 1.5 μm, 1.8 μm or 2 μm, etc. The shape of the groove U can also be square, elliptical or hexagonal, etc. Similarly, the reinforcement part 1422 arranged in the groove U is also square, elliptical or hexagonal. The number of grooves U and reinforcement parts 1422 is multiple, and the number is equal. A reinforcement part 1422 is arranged in a groove U. The reinforcement parts 1422 are arranged in rows along the first direction and in columns along the second direction. Between rows, the reinforcement parts 1422 may be arranged in a regular array or in a staggered arrangement.

[0055] Optionally, the refractive index of the sixth semiconductor layer 133 is greater than the refractive index of the transparent conductive layer 1421, and the refractive index of the transparent conductive layer 1421 is greater than the refractive index of the reinforcement portion 1422. Since the refractive index of the sixth semiconductor layer 133 is different from the refractive index of the second bonding layer 142, the light emitted from the third light emitting structure 130 is refracted at the interface between the sixth semiconductor layer 133 and the second bonding layer 142. Since the difference between the refractive index of the sixth semiconductor layer 133 and the refractive index of the transparent conductive layer 1421 is less than the difference between the refractive index of the sixth semiconductor layer 133 and the refractive index of the reinforcement portion 1422, the light loss caused by refraction at the interface between the sixth semiconductor layer 133 and the second bonding layer 142 is reduced.

[0056] Specifically, the refractive index of the sixth semiconductor layer 133 is between 2.3 and 2.5. Optionally, the refractive index of the sixth semiconductor layer 133 may be 2.30, 2.35, 2.36, 2.40, 2.43, 2.45, 2.48 or 2.50. The refractive index of the transparent conductive layer 1421 is between 1.8 and 2.1. Optionally, the refractive index of the transparent conductive layer 1421 may be 1.80, 1.83, 1.86, 1.90, 1.95, 1.99, 2.00, 2.05, 2.06 or 2.10. The refractive index of the reinforcement portion 1422 is between 1.4 and 1.8. Optionally, the refractive index of the reinforcement portion 1422 is 1.40, 1.45, 1.59, 1.60, 1.73, 1.75 or 1.78.

[0057] The above is for Figure 1 The following is an introduction to the embodiments of the present invention.

[0058] Please refer to Figure 3 , Figure 3 This is a second structural schematic diagram of the light emitting device 100 provided in an embodiment of the present application. Figure 3 Example and Figure 1 The difference of the embodiment is that the second semiconductor layer 113 and the third semiconductor layer 121 are the same semiconductor layer. The fourth semiconductor layer 123 is of the same type as the first semiconductor layer 111 .

[0059] That is, the first semiconductor layer 111 is a hole-type semiconductor layer, the second semiconductor layer 113 is an electron-type semiconductor layer, and the fourth semiconductor layer 123 is a hole-type semiconductor layer. Alternatively, the first semiconductor layer 111 is an electron-type semiconductor layer, the second semiconductor layer 113 is a hole-type semiconductor layer, and the fourth semiconductor layer 123 is an electron-type semiconductor layer.

[0060] Optionally, the first semiconductor layer 111 includes one or more of gallium nitride (GaN), aluminum gallium nitride (AlGaN) or aluminum indium gallium nitride (AlInGaN). The second semiconductor layer 113 includes gallium nitride (GaN). The fourth semiconductor layer 123 includes one or more of gallium nitride, aluminum gallium nitride or aluminum indium gallium nitride. The fifth semiconductor layer 131 includes gallium phosphide (GaP). The sixth semiconductor layer 133 includes gallium arsenide (GaAs). The first light-emitting layer 112 and the second light-emitting layer 122 include quantum well materials of indium gallium nitride (InGaN) or gallium nitride. The third light-emitting layer 132 includes quantum well materials of aluminum indium gallium phosphide (AlInGaP) or gallium indium phosphide (GaInP).

[0061] The second semiconductor layer 113 and the third semiconductor layer 121 are the same semiconductor layer, that is, the first light-emitting structure 110 and the second light-emitting structure 120 share the second semiconductor layer 113. When forming the first light-emitting structure 110 and the second light-emitting structure 120, it is necessary to overcome the stress mismatch, lattice mismatch and thermal expansion mismatch between the film layers. Since the first light-emitting structure 110 and the second light-emitting structure 120 are both made of indium gallium nitride and gallium nitride system materials, the stress mismatch, lattice mismatch and thermal expansion mismatch that need to be overcome between the film layers are relatively small, and there are also fewer defects such as cracks and dislocations formed between the film layers. The film layer quality of the first light-emitting structure 110 and the second light-emitting structure 120 is good, and a higher light extraction efficiency can be achieved.

[0062] Please refer to Figure 4In this embodiment, in the orthographic projection of the plane where the first bonding layer 141 is located, the area of ​​the third light-emitting layer 132 is greater than the area of ​​the first light-emitting layer 112, and the area of ​​the first light-emitting layer 112 is greater than the area of ​​the second light-emitting layer 122. The third light-emitting layer 132 is a red light-emitting layer, the first light-emitting layer 112 is a green light-emitting layer, and the second light-emitting layer 122 is a blue light-emitting layer. Since the photoelectric conversion efficiencies of the red light-emitting layer, the green light-emitting layer, and the blue light-emitting layer are different, the photoelectric conversion efficiency of the blue light-emitting layer is higher than that of the green light-emitting layer, and the photoelectric conversion efficiency of the green light-emitting layer is higher than that of the red light-emitting layer. Therefore, when the areas of the light-emitting layers are equal and the input currents are the same, the luminous intensity of the second light-emitting layer 122 is greater than that of the first light-emitting layer 112, and the luminous intensity of the first light-emitting layer 112 is greater than that of the third light-emitting layer 132. By setting the area of ​​the red light-emitting layer to be greater than that of the green light-emitting layer, and the area of ​​the green light-emitting layer to be greater than that of the blue light-emitting layer, the red, green, and blue light-emitting structures can achieve the same luminous intensity and achieve a better light mixing effect.

[0063] The light emitting device 100 further includes a first electrode E1, a second electrode E2, and a third electrode E3.

[0064] The first electrode E1 is disposed on the fourth semiconductor layer 123 , and is used to electrically connect the fourth semiconductor layer 123 and the driving substrate.

[0065] In the orthographic projection of the plane where the first bonding layer 141 is located, the second semiconductor layer 113 protrudes from the edge of the second light emitting layer 122. The second electrode E2 is disposed on the protruding portion of the second semiconductor layer 113 and is used to electrically connect the second semiconductor layer 113 to the driving substrate.

[0066] In the orthographic projection of the plane where the first bonding layer 141 is located, the sixth semiconductor layer 133 protrudes from the edge of the second bonding layer 142. The third electrode E3 is disposed on the protruding portion of the sixth semiconductor layer 133 and is used to electrically connect the sixth semiconductor layer 133 with the drive substrate.

[0067] The first bonding layer 141 is used to electrically connect the fifth semiconductor layer 131 and the driving substrate.

[0068] The first light emitting structure 110 is connected to the driving substrate through the second electrode E2 and the third electrode E3, the second light emitting structure 120 is connected to the driving substrate through the first electrode E1 and the second electrode E2, and the third light emitting structure 130 is connected to the driving substrate through the third electrode E3 and the fourth electrode. Since the first light emitting structure 110 and the second light emitting structure 120 share the second semiconductor layer 113, the first light emitting structure 110 and the second light emitting structure 120 share the second electrode E2, which can save electrodes and simplify the structure. Since the second bonding layer 142 includes a transparent conductive layer 1421, the first semiconductor layer 111 and the sixth semiconductor layer 133 can be electrically connected, so the first light emitting structure 110 and the third light emitting structure 130 share the third electrode E3, which can save electrodes and simplify the structure.

[0069] Optionally, in the orthographic projection of the plane where the first bonding layer 141 is located, the transparent conductive layer 1421 protrudes from the edge of the first semiconductor layer 111. The third electrode E3 is disposed on the protruding portion of the transparent conductive layer 1421. Alternatively, the first semiconductor layer 111 protrudes from the edge of the first light-emitting layer 112, and the third electrode E3 is disposed on the protruding portion of the first semiconductor layer 111.

[0070] Optionally, the first electrode E1 is connected to the driving substrate via a first wiring. The second electrode E2 is connected to the driving substrate via a second wiring. The third electrode E3 is connected to the driving substrate via a third wiring. The side of the light-emitting device 100 is patterned into a side with a certain slope, so as to facilitate the deposition of the first wiring, the second wiring and the third wiring. An insulating layer is provided between the first wiring, the second wiring, the third wiring and the side of the light-emitting device 100 for insulation.

[0071] The first bonding layer 141 is directly bonded and electrically connected to the pad on the drive substrate as a fourth electrode. The first bonding layer 141 is a metal layer. The bonding structure between the first bonding layer 141 and the pad includes gold-gold bonding (Au Au), gold-tin bonding (Au Sn), gold-indium bonding (Au In), titanium-titanium bonding (Ti Ti) or copper-copper bonding (Cu Cu), etc. The thickness of the first bonding layer 141 is 0.1 to 3 μm. Optionally, the thickness of the first bonding layer 141 is 0.1 μm, 0.3 μm, 0.5 μm, 0.6 μm, 1 μm, 1.2 μm, 1.5 μm, 2 μm, 2.6 μm, 2.8 μm or 3 μm, etc.

[0072] Optionally, the light emitting device 100 is in the shape of a triangular pyramid, a quadrangular pyramid or a hexagonal pyramid. It should be noted that the shape of the light emitting device 100 is the shape after ignoring the electrode and the protruding portion of the electrode setting. The light emitting device 100 is set as a triangular pyramid, a quadrangular pyramid or a hexagonal pyramid, the first electrode E1 is set on an edge, and the first wiring is set on the corresponding edge surface. Similarly, the second electrode E2 is set on another edge, and the second wiring is set on the corresponding edge surface. The third electrode E3 is set on another edge, and the third wiring is set on the corresponding edge surface. In this way, the first wiring, the second wiring and the third wiring can be set separately to prevent interference between the electrodes and the wiring, causing a short circuit and causing damage to the light emitting device 100.

[0073] A transparent insulating layer is disposed on the surface of the fourth semiconductor layer 123 not covered by the first electrode E1 for insulation, and at the same time, the transparent insulating layer can pass the light emitted by the light emitting device 100 to improve the light extraction efficiency.

[0074] In this embodiment, the light emitting device 100 further includes a current diffusion layer D. At least part of the current diffusion layer D is located between the second electrode E2 and the second semiconductor layer 113. The current diffusion layer D is connected to the second electrode E2 and the second semiconductor layer 113. The current diffusion layer D is provided between the second electrode E2 and the second semiconductor layer 113, so as to improve the reaction rate and current transmission efficiency of the second electrode E2.

[0075] Optionally, the light-emitting device 100 includes a periodic stress adjustment layer. The periodic stress adjustment layer is arranged between the fourth semiconductor layer 123 and the transparent insulating layer. When preparing the first light-emitting structure 110 and the second light-emitting structure 120, the periodic stress adjustment layer is arranged on the substrate to help adjust the film layer stress, so as to facilitate the continued growth of the fourth semiconductor layer 123, the second light-emitting layer 122, the second semiconductor layer 113, the first light-emitting layer 112 and the first semiconductor layer 111 on the substrate. The periodic stress adjustment layer is arranged between the sixth semiconductor layer 133 and the second bonding layer 142. When preparing the third light-emitting structure 130, the periodic stress adjustment layer is arranged on the substrate to help adjust the film layer stress, so as to facilitate the continued growth of the sixth semiconductor layer 133, the third light-emitting layer 132 and the fifth semiconductor layer 131 on the substrate.

[0076] Optionally, the light emitting device 100 further includes a reflective layer. The reflective layer is disposed between the first semiconductor layer 111 and the second bonding layer 142, or disposed on the side of the light emitting device 100 to improve the forward light emission of the light emitting device 100 and improve the light emission efficiency. In addition, the first bonding layer 141 is a metal layer with a reflective effect, and can also be used as a reflective layer to reflect the light irradiated onto the first bonding layer 141 by the first light emitting structure 110, the second light emitting structure 120, and the third light emitting structure 130.

[0077] The above is for Figure 3The following is an introduction to the embodiments of the present invention. Figure 3 The remaining structures of the embodiment are the same as Figure 1 The embodiments are the same as those of the present invention and will not be described in detail here.

[0078] Please refer to Figure 5 , Figure 5 This is a third structural schematic diagram of the light emitting device 100 provided in an embodiment of the present application. Figure 5 Example and Figure 3 The difference between the embodiments is that the light emitting device 100 further includes an alignment layer 134 .

[0079] Specifically, the material of the aligning layer 134 is the same as that of the reinforcing portion 1422. In the present embodiment, the material of the reinforcing portion 1422 is silicon dioxide, and the material of the aligning layer 134 is also silicon dioxide. The aligning layer 134 is disposed on a side of the sixth semiconductor layer 133 away from the third light-emitting layer 132, and the aligning layer 134 corresponds to the groove U. The aligning layer 134 is bonded to the reinforcing portion 1422. Since the aligning layer 134 is made of the same material as that of the reinforcing portion 1422, the aligning layer 134 is disposed on a side of the sixth semiconductor layer 133 away from the third light-emitting layer 132, and the aligning layer 134 is more easily bonded to the reinforcing portion 1422, which can further improve the bonding efficiency and bonding strength.

[0080] Figure 5 The remaining structures of the embodiment are the same as Figure 3 The embodiments are the same as those of the present invention and will not be described in detail here.

[0081] Please refer to Figure 6 , Figure 6 This is a fourth structural schematic diagram of the light emitting device 100 provided in an embodiment of the present application. Figure 6 Example and Figure 3 The difference between the embodiments is that the third light emitting structure 130 and the first light emitting structure 110 share the first semiconductor layer 111 .

[0082] Specifically, the light emitting device 100 includes a third light emitting structure 130 and a bonding layer 140. The bonding layer 140 is used to bond the third light emitting structure 130 to the driving substrate. In this embodiment, no bonding layer is provided between the third light emitting structure 130 and the first light emitting structure 110.

[0083] The third light emitting structure 130 includes a first semiconductor layer 111, a third light emitting layer 132 and a fifth semiconductor layer 131. The third light emitting layer 132 is disposed on a side of the first semiconductor layer 111 away from the first light emitting layer 112. The fifth semiconductor layer 131 is disposed on a side of the third light emitting layer 132 away from the first semiconductor layer 111. The fifth semiconductor layer 131 is of the same type as the second semiconductor layer 113. The third light emitting structure 130 and the first light emitting structure 110 share the first semiconductor layer 111. In this embodiment, on the basis of reducing the bonding layer between the first light emitting structure 110 and the second light emitting structure 120, the bonding layer between the first light emitting structure 110 and the third light emitting structure 130 is reduced, and the first light emitting structure 110, the second light emitting structure 120 and the third light emitting structure 130 can be bonded to the driving substrate by only one bonding. The light loss due to the bonding layer is further reduced, the number of bonding processes is further reduced, and the quality and yield of the light emitting device 100 are improved.

[0084] The fifth semiconductor layer 131 is of the same type as the second semiconductor layer 113. That is, the first semiconductor layer 111 is a hole-type semiconductor layer, the second semiconductor layer 113 is an electron-type semiconductor layer, the fourth semiconductor layer 123 is a hole-type semiconductor layer, and the fifth semiconductor layer 131 is an electron-type semiconductor layer. Alternatively, the first semiconductor layer 111 is an electron-type semiconductor layer, the second semiconductor layer 113 is a hole-type semiconductor layer, the fourth semiconductor layer 123 is an electron-type semiconductor layer, and the fifth semiconductor layer 131 is a hole-type semiconductor layer.

[0085] Figure 6 The remaining structures of the embodiment are the same as Figure 3 The embodiments are the same as those of the present invention and will not be described in detail here.

[0086] Please refer to Figure 7 , Figure 7 The structure diagram of the display panel 1000 provided in the embodiment of the present application is shown in FIG. The display panel 1000 includes any of the above-mentioned light-emitting devices 100 and a driving substrate 200 . The light-emitting device 100 is disposed on the driving substrate 200 .

[0087] This application also provides Figure 3 A method for manufacturing a display panel 1000 including a light emitting device 100 according to an embodiment.

[0088] Please refer to Figure 8 , Figure 8 To prepare Figure 3 Flow chart of a display panel 1000 including a light emitting device 100. Figure 3 The method for preparing the light emitter of the embodiment comprises the following steps:

[0089] Step S1, providing a driving substrate 200;

[0090] Step S2, preparing a third light emitting structure 130 and a first bonding layer 141;

[0091] Step S3, preparing the first light emitting structure 110, the second light emitting structure 120 and the second bonding layer 142;

[0092] Step S4, the third light emitting structure 130 is bonded to the driving substrate 200 via the first bonding layer 141;

[0093] Step S5, the second light emitting structure 120, the first light emitting structure 110 and the third light emitting structure 130 are bonded via the second bonding layer 142;

[0094] Step S6 , preparing the first electrode E1 , the second electrode E2 and the third electrode E3 , and electrically connecting the first electrode E1 , the second electrode E2 and the third electrode E3 to the driving substrate 200 , respectively.

[0095] The following describes each step.

[0096] Please refer to Fig. 9 Step S1, providing a driving substrate 200. Specifically, the driving substrate 200 exposes a bonding pad. The bonding pad is used to electrically connect with the first electrode E1, the second electrode E2, the third electrode E3 and the first bonding layer 141 of the light emitting device 100.

[0097] Next, proceed to step S2.

[0098] Step S2 , preparing the third light emitting structure 130 and the first bonding layer 141 .

[0099] Specifically, a first substrate is provided, and a sixth semiconductor layer 133, a third light emitting layer 132, a fifth semiconductor layer 131 and a first bonding layer 141 are sequentially formed on the first substrate, wherein the first substrate is a gallium arsenide substrate.

[0100] Next, proceed to step S3.

[0101] Step S3 , preparing the first light emitting structure 110 , the second light emitting structure 120 , the current diffusion layer D and the second bonding layer 142 .

[0102] Specifically, a second substrate is provided. A fourth semiconductor layer 123, a second light-emitting layer 122, a second semiconductor layer 113, a first light-emitting layer 112, a first semiconductor layer 111, a current diffusion layer D and a second bonding layer 142 are sequentially formed on the second substrate. The first light-emitting structure 110 and the second light-emitting structure 120 are directly coaxially grown on the second substrate. The second substrate is a sapphire substrate or a silicon substrate. The second substrate may also be a substrate comprising one or more materials selected from gallium nitride, aluminum nitride, silicon and silicon carbide.

[0103] Taking the transparent conductive layer 1421 as an example of indium tin oxide and the reinforcement part 1422 as silicon dioxide, the formation of the second bonding layer 142 specifically includes: forming a 3 μm thick indium tin oxide film on the side of the current diffusion layer D away from the first semiconductor layer 111. Forming a circular groove U on the side of the indium tin oxide film away from the first semiconductor layer 111 by photolithography to form the transparent conductive layer 1421. Forming a 1.5-1 μm thick silicon dioxide film on the side of the transparent conductive layer 1421 away from the first semiconductor layer 111. Grinding by chemical mechanical polishing technology until the transparent conductive layer 1421 is exposed. At this point, the reinforcement part 1422 made of silicon dioxide is formed in the groove U of the transparent conductive layer 1421.

[0104] Next, step S4 is performed.

[0105] Please refer to Fig.10 , step S4 , the third light emitting structure 130 is bonded to the driving substrate 200 through the first bonding layer 141 .

[0106] Specifically, the first bonding layer 141 is formed on the third light emitting structure 130 and the first substrate, and the first bonding layer 141 is bonded and electrically connected to the pad exposed by the driving substrate 200 to complete the bonding. After the bonding is completed, the first substrate is removed to expose the sixth semiconductor layer 133.

[0107] Next, step S5 is performed.

[0108] Please refer to Fig.11 In step S5 , the second light emitting structure 120 , the first light emitting structure 110 and the third light emitting structure 130 are bonded via the second bonding layer 142 .

[0109] Specifically, the second bonding layer 142 is formed on the current diffusion layer D, the first light emitting structure 110, the second light emitting structure 120 and the second substrate. The second bonding layer 142 is bonded and electrically connected to the sixth semiconductor layer 133 of the third light emitting structure 130 to complete the bonding. After the bonding is completed, the second substrate is removed to expose the fourth semiconductor layer 123.

[0110] After step S5 and before step S6, the preparation method of this embodiment further includes the following steps:

[0111] The first light-emitting structure 110, the second light-emitting structure 120 and the third light-emitting structure 130 are patterned so that the side of the light-emitting device 100 has a certain slope, and the second semiconductor layer 113 and the current diffusion layer D protrude from the second light-emitting layer 122, and the sixth semiconductor layer 133 protrude from the second bonding layer 142. An insulating layer is prepared on the side of the light-emitting device 100, and the protruding parts of the second semiconductor layer 113 and the current diffusion layer D are not completely covered by the insulating layer, so as to set the second electrode E2. The protruding parts of the sixth semiconductor layer 133 are not completely covered by the insulating layer, so as to set the third electrode E3. A transparent insulating layer is prepared on the surface of the fourth semiconductor layer 123 away from the second light-emitting layer 122. An opening is opened in the transparent insulating layer to expose the surface of the fourth semiconductor layer 123, so as to set the first electrode E1.

[0112] Step S6 , preparing the first electrode E1 , the second electrode E2 and the third electrode E3 , and electrically connecting the first electrode E1 , the second electrode E2 and the third electrode E3 to the driving substrate 200 , respectively.

[0113] Specifically, a first electrode E1 is disposed in the opening of the transparent insulating layer, and the first electrode E1 is electrically connected to the fourth semiconductor layer 123. A second electrode E2 is formed on the protruding portion of the second semiconductor layer 113, and the second electrode E2 is electrically connected to the second semiconductor layer 113. A third electrode E3 is formed on the protruding portion of the sixth semiconductor layer 133, and the third electrode E3 is electrically connected to the sixth semiconductor layer 133.

[0114] Optionally, a first wiring is formed on the side of the light emitting device 100, and the first wiring is connected between the first electrode E1 and the driving substrate 200. A second wiring is formed on the side of the light emitting device 100, and the second wiring is connected between the second electrode E2 and the driving substrate 200. A third wiring is formed on the side of the light emitting device 100, and the third wiring is connected between the third electrode E3 and the driving substrate 200.

[0115] So far, the following has been completed: Figure 3 Preparation of a display panel 1000 including the light emitting device 100.

[0116] The light emitting device 100 and the display panel 1000 provided in the present application are introduced in detail above.

[0117] The light-emitting device provided in the embodiment of the present application includes a first light-emitting structure and a second light-emitting structure directly grown on the first light-emitting structure. The first light-emitting structure includes a first semiconductor layer, a first light-emitting layer, and a second semiconductor layer stacked in sequence. The second light-emitting structure includes a third semiconductor layer, a second light-emitting layer, and a fourth semiconductor layer stacked in sequence. By directly setting the second light-emitting structure on the first light-emitting structure, the setting of the bonding layer between the first light-emitting structure and the second light-emitting structure is reduced, thereby reducing the light loss caused by the setting of the bonding layer. And since the number of bonding processes is reduced by reducing the setting of the bonding layer, the damage to the light-emitting device caused by the bonding process is reduced, thereby improving the quality and yield of the light-emitting device. The display panel provided in the embodiment of the present application includes the above-mentioned light-emitting device.

[0118] Specific examples are used herein to illustrate the principles and implementation methods of the present application, and the description of the above embodiments is only used to help understand the core idea of ​​the present application. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application.

Claims

1. A light emitting device, characterized in that: The light emitting device comprises a first light emitting structure and a second light emitting structure directly grown on the first light emitting structure, wherein the first light emitting structure comprises a first semiconductor layer, a first light emitting layer, and a second semiconductor layer stacked in sequence, and the second light emitting structure comprises a third semiconductor layer, a second light emitting layer, and a fourth semiconductor layer stacked in sequence; In the first light emitting structure, the first semiconductor layer is one of a hole-type semiconductor layer and an electron-type semiconductor layer, and the second semiconductor layer is the other of the hole-type semiconductor layer and the electron-type semiconductor layer; In the second light emitting structure, the third semiconductor layer is one of a hole-type semiconductor layer and an electron-type semiconductor layer, and the fourth semiconductor layer is the other of the hole-type semiconductor layer and the electron-type semiconductor layer.

2. The light emitting device according to claim 1, characterized in that: The second semiconductor layer and the third semiconductor layer are the same semiconductor layer, and the fourth semiconductor layer is of the same type as the first semiconductor layer.

3. The light emitting device according to claim 2, characterized in that: The light emitting device further comprises a third light emitting structure and a bonding layer, wherein the bonding layer is used for bonding the third light emitting structure to the driving substrate; The third light-emitting structure includes the first semiconductor layer, a third light-emitting layer and a fifth semiconductor layer. The third light-emitting layer is arranged on a side of the first semiconductor layer away from the first light-emitting layer, the fifth semiconductor layer is arranged on a side of the third light-emitting layer away from the first semiconductor layer, the fifth semiconductor layer is of the same type as the second semiconductor layer, and the third light-emitting structure and the first light-emitting structure share the first semiconductor layer.

4. The light emitting device according to claim 1, characterized in that: The light emitting device further includes a third light emitting structure, a first bonding layer and a second bonding layer, wherein the first bonding layer is used to bond the third light emitting structure to the driving substrate, and the first light emitting structure is bonded and arranged on the third light emitting structure through the second bonding layer; The third light emitting structure includes a fifth semiconductor layer, a third light emitting layer and a sixth semiconductor layer which are stacked in sequence, the fifth semiconductor layer is one of a hole-type semiconductor layer or an electron-type semiconductor layer, and the sixth semiconductor layer is the other of the hole-type semiconductor layer or the electron-type semiconductor layer.

5. The light emitting device according to claim 4, characterized in that: The second bonding layer is disposed on a side of the first semiconductor layer away from the first light emitting layer, and the second bonding layer includes a transparent conductive layer, and the first semiconductor layer and the sixth semiconductor layer are bonded and electrically connected via the transparent conductive layer.

6. The light-emitting device according to claim 5, wherein the second bonding layer further comprises a reinforcement portion, and the bonding strength between the reinforcement portion and the sixth semiconductor layer is greater than the bonding strength between the transparent conductive layer and the sixth semiconductor layer; A groove is formed on a surface of the transparent conductive layer facing the third light emitting structure, the reinforcing portion is arranged in the groove, and the reinforcing portion is bonded to the sixth semiconductor layer.

7. The light emitting device according to claim 5, characterized in that: The second bonding layer further includes a reinforcement portion, and the bonding strength between the reinforcement portion and the sixth semiconductor layer is greater than the bonding strength between the transparent conductive layer and the sixth semiconductor layer; A groove is formed on a side of the transparent conductive layer facing the third light emitting structure, and the reinforcing part is arranged in the groove; The light emitting device further comprises an alignment layer, the material of the alignment layer is the same as the material of the reinforcement part, the alignment layer is arranged on a side of the sixth semiconductor layer away from the third light emitting layer, the alignment layer corresponds to the groove, and the alignment layer is bonded to the reinforcement part.

8. The light emitting device according to any one of claims 6 or 7, characterized in that: The refractive index of the sixth semiconductor layer is greater than the refractive index of the transparent conductive layer, and the refractive index of the transparent conductive layer is greater than the refractive index of the reinforcing portion.

9. The light emitting device according to claim 3 or 4, characterized in that: In the orthographic projection of the plane where the first bonding layer is located, the area of ​​the third light-emitting layer is larger than the area of ​​the first light-emitting layer, and the area of ​​the first light-emitting layer is larger than the area of ​​the second light-emitting layer; The third light-emitting layer is a red light-emitting layer, the first light-emitting layer is a green light-emitting layer, and the second light-emitting layer is a blue light-emitting layer.

10. A display panel, characterized in that: The display panel comprises the light emitting device according to any one of claims 1 to 9, and the display panel further comprises a driving substrate, and the light emitting device is arranged on the driving substrate.

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