Light emitting diode with improved luminous efficiency and method of manufacturing the same

Abstract

The present disclosure provides a light emitting diode with improved light emitting efficiency and a preparation method thereof, and belongs to the technical field of optoelectronic manufacturing. The light emitting diode comprises a first epitaxial layer, a second epitaxial layer, a connecting structure and a conductive structure; the first epitaxial layer, the connecting structure and the second epitaxial layer are sequentially stacked, the surface of the second epitaxial layer has a first groove extending to the connecting structure, the conductive structure is located at least in the surface of the connecting structure, the surface of the second epitaxial layer and the first groove, the conductive structure is electrically connected with the first epitaxial layer through the connecting structure, and the conductive structure is electrically connected with the second epitaxial layer. The present disclosure can increase the light emitting area of the light emitting diode, reduce the area loss of the high-voltage light emitting diode, realize the high-voltage light emitting diode with smaller size, and improve the light emitting efficiency.

Description

Technical Field

[0001] This disclosure relates to the field of optoelectronic manufacturing technology, and in particular to a light-emitting diode with improved luminous efficiency and a method for its fabrication. Background Technology

[0002] Light-emitting diodes (LEDs) are highly influential new products in the optoelectronics industry. They are characterized by their small size, long lifespan, rich and colorful colors, and low energy consumption. They are widely used in lighting, displays, signal lights, backlights, toys, and other fields.

[0003] In related technologies, light-emitting diodes typically include a substrate, an epitaxial layer, and electrodes stacked sequentially. To improve luminous efficiency, two epitaxial layers with the same luminous color are usually disposed on the substrate. The two epitaxial layers are usually connected in series and arranged horizontally on the substrate.

[0004] Because of the small size of light-emitting diodes (LEDs), if the two epitaxial layers are horizontally distributed and there is a gap between them, the area used for light emission in the LED will be too small, affecting the luminous efficiency. Summary of the Invention

[0005] This disclosure provides a light-emitting diode (LED) with improved luminous efficiency and its fabrication method, which can increase the light-emitting area of ​​the LED, reduce the area loss in realizing a high-voltage LED, realize a high-voltage LED in a smaller size, and improve luminous efficiency. The technical solution is as follows:

[0006] This disclosure provides a light-emitting diode (LED) comprising: a first epitaxial layer, a second epitaxial layer, a connection structure, and a conductive structure; the first epitaxial layer, the connection structure, and the second epitaxial layer are stacked sequentially, the surface of the second epitaxial layer has a first groove extending to the connection structure, the conductive structure is located at least on the surface of the connection structure, the surface of the second epitaxial layer, and within the first groove, the conductive structure is electrically connected to the first epitaxial layer through the connection structure, and the conductive structure is electrically connected to the second epitaxial layer.

[0007] In one implementation of this disclosure, the conductive structure includes a first insulating layer and a first conductive layer. The first insulating layer is located at least within the first groove and on the sidewall of the second epitaxial layer and the sidewall of the connection structure. The first conductive layer is located at least on the surface of the connection structure, the surface of the second epitaxial layer, and the surface of the first insulating layer.

[0008] In another implementation of the embodiments of this disclosure, the first conductive layer is a transparent conductive layer or a metal layer.

[0009] In another implementation of the present disclosure, the connection structure includes a second conductive layer, a bonding layer and a third conductive layer sequentially stacked on the surface of the first epitaxial layer, wherein the second conductive layer and the third conductive layer are both transparent conductive layers; the first groove exposes the second conductive layer, and the first conductive layer is located on the second conductive layer.

[0010] In another implementation of this disclosure, the surface of the second epitaxial layer has a second groove exposing the third conductive layer; the light-emitting diode further includes a first electrode and a second insulating layer, the second insulating layer being located at least on the surface of the second epitaxial layer, the surface of the conductive structure, within the first groove and within the second groove, the second insulating layer having a first through hole exposing the third conductive layer, the first electrode being located at least on the surface of the second insulating layer and within the second groove, and being connected to the third conductive layer through the first through hole.

[0011] In another implementation of the present disclosure, the light-emitting diode further includes a second electrode, the surface of the second epitaxial layer has a third groove exposing the first epitaxial layer, the second insulating layer is located in the third groove, the second insulating layer has a second through hole exposing the first epitaxial layer, the second electrode is at least partially located in the third groove, and is connected to the first epitaxial layer through the second through hole.

[0012] In another implementation of the present disclosure, the first groove, the second groove, and the third groove are all located at the edge of the second epitaxial layer.

[0013] In another implementation of the present disclosure, the light-emitting diode further includes a second electrode located on the surface of the first epitaxial layer away from the second epitaxial layer.

[0014] In another implementation of the present disclosure, the first epitaxial layer includes a first n-type layer, a first light-emitting layer, and a first p-type layer stacked sequentially, and the second epitaxial layer includes a second p-type layer, a second light-emitting layer, and a second n-type layer stacked sequentially on the connection structure.

[0015] This disclosure provides a method for fabricating a light-emitting diode (LED). The method includes: forming a first epitaxial layer and a second epitaxial layer; bonding the first epitaxial layer and the second epitaxial layer to form a connection structure between the first epitaxial layer and the second epitaxial layer; forming a first groove on the surface of the second epitaxial layer extending to the connection structure; forming a conductive structure in the first groove; the conductive structure being located at least on the surface of the connection structure, the surface of the second epitaxial layer, and in the first groove; the conductive structure being electrically connected to the first epitaxial layer through the connection structure, and the conductive structure being electrically connected to the second epitaxial layer.

[0016] The beneficial effects of the technical solutions provided in this disclosure include at least the following:

[0017] The light-emitting diode provided in this embodiment includes a first epitaxial layer and a second epitaxial layer stacked together. The surface of the second epitaxial layer has a first groove extending to the connection structure. A conductive structure is also provided in the first groove. The conductive structure is located at least on the surface of the connection structure, the surface of the second epitaxial layer and the first groove, so as to connect the first epitaxial layer and the second epitaxial layer in series. In this way, when the light-emitting diode is energized, the first epitaxial layer and the second epitaxial layer can generate electricity simultaneously, so as to greatly improve the luminous brightness.

[0018] Compared to the two horizontally arranged epitaxial layers in related technologies, the two stacked epitaxial layers do not have gaps in the horizontal direction. Therefore, the two epitaxial layers can be designed according to the maximum size of the light-emitting diode, which can maximize the area of ​​the light-emitting region in the light-emitting diode, thereby improving the luminous efficiency of the light-emitting diode. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a top view of a light-emitting diode provided in an embodiment of this disclosure;

[0021] Figure 2 yes Figure 1 Provided AA section diagram;

[0022] Figure 3 This is a cross-sectional view of a light-emitting diode provided in an embodiment of this disclosure;

[0023] Figure 4 yes Figure 1 Provided BB cross-section diagram;

[0024] Figure 5 This is a schematic diagram of another light-emitting diode structure provided in an embodiment of this disclosure;

[0025] Figure 6 This is a flowchart of a method for fabricating a light-emitting diode provided in an embodiment of this disclosure;

[0026] Figure 7 This is a fabrication state diagram of a light-emitting diode provided in an embodiment of this disclosure;

[0027] Figure 8 This is a fabrication state diagram of a light-emitting diode provided in an embodiment of this disclosure;

[0028] Figure 9 yes Figure 8 Provided CC section diagram;

[0029] Figure 10 yes Figure 8 The provided DD cross-sectional diagram.

[0030] The markings in the diagram are explained as follows:

[0031] 10. Substrate;

[0032] 21. First epitaxial layer; 211. First n-type layer; 212. First luminescent layer; 213. First p-type layer;

[0033] 22. Second epitaxial layer; 221. Second p-type layer; 222. Second luminescent layer; 223. Second n-type layer;

[0034] 201. First groove; 202. Second groove; 203. Third groove;

[0035] 30. Connection structure; 31. Second conductive layer; 32. Bonding layer; 33. Third conductive layer;

[0036] 40. Conductive structure; 41. First insulating layer; 42. First conductive layer;

[0037] 51. First electrode; 52. Second electrode; 53. First through hole; 54. Second through hole; 55. Second insulating layer. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this disclosure clearer, the embodiments of this disclosure will be described in further detail below with reference to the accompanying drawings.

[0039] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” “third,” and similar terms used in this patent application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an” or “a” and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms “comprising” or “including” and similar terms mean that the elements or objects preceding “comprising” or “including” encompass the elements or objects listed following “comprising” or “including” and their equivalents, and do not exclude other elements or objects. The terms “connected” or “linked” and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms “upper,” “lower,” “left,” “right,” “top,” and “bottom,” etc., are used only to indicate relative positional relationships, and these relative positional relationships may change accordingly when the absolute position of the described objects changes.

[0040] Figure 1 This is a top view of a light-emitting diode provided in an embodiment of this disclosure. Figure 1 As shown, the light-emitting diode includes: a first epitaxial layer 21, a second epitaxial layer 22, a connection structure 30, and a conductive structure 40.

[0041] Figure 2 yes Figure 1 The provided AA cross-sectional diagram. (For example...) Figure 2 As shown, the first epitaxial layer 21, the connecting structure 30, and the second epitaxial layer 22 are stacked sequentially. The surface of the second epitaxial layer 22 has a first groove 201 extending to the connecting structure 30. The conductive structure 40 is located at least on the surface of the connecting structure 30, the surface of the second epitaxial layer 22, and within the first groove 201. The conductive structure 40 is electrically connected to the first epitaxial layer 21 through the connecting structure 30, and is also electrically connected to the second epitaxial layer 22.

[0042] The first epitaxial layer 21 and the second epitaxial layer 22 emit the same color.

[0043] The light-emitting diode provided in this embodiment includes a first epitaxial layer 21 and a second epitaxial layer 22 stacked together. The surface of the second epitaxial layer 22 has a first groove 201 extending to the first epitaxial layer 21. A conductive structure 40 is also provided in the first groove 201. The conductive structure 40 is located at least on the surface of the first epitaxial layer 21, the surface of the second epitaxial layer 22 and in the first groove 201, so as to connect the first epitaxial layer 21 and the second epitaxial layer 22 in series. In this way, when the light-emitting diode is powered on, the first epitaxial layer 21 and the second epitaxial layer 22 can generate electricity simultaneously, so as to greatly improve the light brightness.

[0044] Compared to the two horizontally arranged epitaxial layers in related technologies, the two stacked epitaxial layers do not have gaps in the horizontal direction. Therefore, the two epitaxial layers can be designed according to the maximum size of the light-emitting diode, which can maximize the area of ​​the light-emitting region in the light-emitting diode, thereby improving the luminous efficiency of the light-emitting diode.

[0045] Optionally, such as Figure 2 As shown, the conductive structure 40 includes a first insulating layer 41 and a first conductive layer 42. The first insulating layer 41 is located at least within the first groove 201 and is located on the sidewall of the second epitaxial layer 22 and the sidewall of the connecting structure 30. The first conductive layer 42 is located at least on the surface of the connecting structure 30, the surface of the second epitaxial layer 22, and the surface of the first insulating layer 41.

[0046] In this embodiment, a first groove 201 is provided on the surface of the second epitaxial layer 22. The first groove 201 is used to allow the conductive structure 40 to extend to the first epitaxial layer 21, connecting the film structure of the first epitaxial layer 21 and the second epitaxial layer 22. After providing the first groove 201, a first insulating layer 41 is provided on the sidewall of the second epitaxial layer 22 and the sidewall of the connecting structure 30 to isolate the sidewall of the second epitaxial layer 22 and the sidewall of the connecting structure 30 from the first conductive layer 42. This effectively avoids the problem of short circuits caused by contact between the conductive structure 40 and the sidewall of the second epitaxial layer 22 and the sidewall of the connecting structure 30, thereby improving the stability of the light-emitting diode.

[0047] The first insulating layer 41 can be a film layer such as SiO2, SiN, or Al2O3.

[0048] For example, the first conductive layer 42 may be a transparent conductive layer.

[0049] For example, the transparent conductive layer can be an indium tin oxide (ITO) film. Indium tin oxide films have good transmittance and low resistivity. Using an indium tin oxide film as the transparent conductive layer allows more light to pass through, thus ensuring optimal performance. Simultaneously, due to its low resistivity, it also facilitates carrier conduction, improving injection efficiency.

[0050] When the transparent conductive layer is an ITO layer, the thickness of the transparent conductive layer can be from 50 angstroms to 5000 angstroms.

[0051] For example, the transparent conductive layer can be a NiAu layer. The NiAu layer has good light transmittance, which not only facilitates carrier conduction but also effectively prevents the light from being blocked from the epitaxial layer.

[0052] When the transparent conductive layer is a NiAu layer, the thickness of the transparent conductive layer can be no more than 20 angstroms.

[0053] For example, the first conductive layer 42 can be a metal layer. Since the first conductive layer 42 is disposed within the first groove 201 to connect the first epitaxial layer 21 and the second epitaxial layer 22, the area of ​​the first conductive layer 42 is relatively small. Therefore, the first conductive layer 42 can also be a non-transparent film structure. For example, the first conductive layer 42 can be an Au layer and a Cu layer, etc.

[0054] Figure 3 This is a cross-sectional view of a light-emitting diode provided in an embodiment of this disclosure. For example... Figure 3 As shown, the first epitaxial layer 21 includes a first n-type layer 211, a first light-emitting layer 212, and a first p-type layer 213 stacked sequentially. The second epitaxial layer 22 includes a second p-type layer 221, a second light-emitting layer 222, and a second n-type layer 223 stacked sequentially on the connecting structure 30. That is, the first p-type layer 213 of the first epitaxial layer 21 is opposite to the second p-type layer 221 of the second epitaxial layer 22.

[0055] The first epitaxial layer 21 and the second epitaxial layer 22 emit the same color. Therefore, the first epitaxial layer 21 and the second epitaxial layer 22 can be made of the same material.

[0056] For example, both the first epitaxial layer 21 and the second epitaxial layer 22 can be blue light epitaxial layers.

[0057] For example, the first p-type layer 213 and the second p-type layer 221 may be p-type AlInP layers.

[0058] For example, the first light-emitting layer 212 and the second light-emitting layer 222 may include alternately grown InGaN quantum well layers and GaN quantum barrier layers. The first light-emitting layer 212 may include 3 to 8 alternating stacked InGaN quantum well layers and GaN quantum barrier layers.

[0059] For example, the first n-type layer 211 and the second n-type layer 223 may be n-type GaN layers.

[0060] Optionally, such as Figure 2 As shown, the connection structure 30 includes a second conductive layer 31, a bonding layer 32 and a third conductive layer 33, which are sequentially stacked on the surface of the first epitaxial layer 21.

[0061] like Figure 3 As shown, the second conductive layer 31 is located on the surface of the first p-type layer 213 to be electrically connected to the first p-type layer 213.

[0062] like Figure 3 As shown, the third conductive layer 33 is located between the bonding layer 32 and the second p-type layer 221, so as to be electrically connected to the second p-type layer 221.

[0063] like Figure 2 , 3 As shown, the first groove 201 exposes the second conductive layer 31, and the first conductive layer 42 is located on the second conductive layer 31. In this way, the first conductive layer 42 can be electrically connected to the first p-type layer 213 through the second conductive layer 31. Since the first conductive layer 42 is located on the surface of the second n-type layer 223 of the second epitaxial layer 22, the first conductive layer 42 can connect the first p-type layer 213 and the second n-type layer 223, thereby realizing the series connection of the first epitaxial layer 21 and the second epitaxial layer 22.

[0064] For example, both the second conductive layer 31 and the third conductive layer 33 can be transparent conductive layers.

[0065] For example, the transparent conductive layer can be an ITO layer. ITO layers have good transmittance and low resistivity. Using an ITO layer as a transparent conductive layer allows more light to pass through, thus ensuring the desired effect. At the same time, due to its low resistivity, it also facilitates carrier conduction and improves injection efficiency.

[0066] When the transparent conductive layer is an ITO layer, the thickness of the transparent conductive layer can be from 50 angstroms to 5000 angstroms.

[0067] For example, the transparent conductive layer can be a NiAu layer. The NiAu layer has good light transmittance, which not only facilitates carrier conduction but also effectively prevents the light from being blocked from the epitaxial layer.

[0068] When the transparent conductive layer is a NiAu layer, the thickness of the transparent conductive layer can be no more than 20 angstroms.

[0069] For example, the bonding layer 32 may be made of an insulating material to block current conduction between the first epitaxial layer 21 and the second epitaxial layer 22.

[0070] The thickness of the bonding layer 32 can be from 0.5 μm to 3 μm.

[0071] Figure 4 yes Figure 1 The provided BB cross-sectional diagram. (Example) Figure 1 , 4 As shown, the surface of the second epitaxial layer 22 has a second groove 202 that exposes the third conductive layer 33.

[0072] like Figure 4As shown, the light-emitting diode also includes a first electrode 51 and a second insulating layer 55. The second insulating layer 55 is located at least on the surface of the second epitaxial layer 22, the surface of the conductive structure 40, in the first groove 201 and in the second groove 202. The second insulating layer 55 has a first through hole 53 exposing the third conductive layer 33. The first electrode 51 is located at least on the surface of the second insulating layer 55 and in the second groove 202, and is connected to the third conductive layer 33 through the first through hole 53.

[0073] Combination Figure 3 The third conductive layer 33 is electrically connected to the second p-type layer 221. The first electrode 51 is located on the second insulating layer 55 and extends into the second groove 202, and is connected to the third conductive layer 33 through the first through-hole 53. This makes the first electrode 51 located on the second epitaxial layer 22 electrically connected to the second p-type layer 221, so as to conduct electricity to the p-type layer of the two epitaxial layers connected in series through the first electrode 51.

[0074] Meanwhile, a second insulating layer 55 is provided between the second n-type layer 223 and the third conductive layer 33, which can effectively prevent the third conductive layer 33 from contacting the second n-type layer 223 and causing a short circuit, thereby improving the stability of the light-emitting diode.

[0075] The second insulating layer 55 can be a film layer such as SiO2, SiN, or Al2O3.

[0076] In some implementations disclosed herein, such as Figure 1 , 4 As shown, the light-emitting diode also includes a substrate 10 and a second electrode 52, and the first electrode 51 and the second electrode 52 are both located on the same side of the substrate 10.

[0077] like Figure 1 , 4 As shown, the substrate 10 is located on the surface of the first epitaxial layer 21 away from the second epitaxial layer 22. The surface of the second epitaxial layer 22 has a third groove 203 that exposes the first epitaxial layer 21. The second insulating layer 55 is located in the third groove 203. The second insulating layer 55 has a second through hole 54 that exposes the first epitaxial layer 21. The second electrode 52 is at least partially located in the third groove 203 and is connected to the first epitaxial layer 21 through the second through hole 54.

[0078] In this implementation method, combined with Figure 3The surface of the second epitaxial layer 22 also has a third groove 203 exposing the first n-type layer 211. This allows the second electrode 52 to be positioned on one side of the second epitaxial layer 22 and extend through the third groove 203 to the first n-type layer 211, where it is electrically connected. Since the first electrode 51 is electrically connected to the second p-type layer 221 of the second epitaxial layer 22, and the second electrode 52 is electrically connected to the first p-type layer 213 of the first epitaxial layer 21, and the first n-type layer 211 of the first epitaxial layer 21 and the second p-type layer 221 of the second epitaxial layer 22 are electrically connected through the conductive structure 40, the purpose of energizing both epitaxial layers can be achieved using only the first electrode 51 and the second electrode 52, making it convenient to use.

[0079] The substrate is a sapphire substrate 10, a silicon substrate 10, or a silicon carbide substrate 10. The substrate 10 can be a flat substrate 10 or a patterned substrate 10.

[0080] As an example, in this embodiment of the disclosure, the substrate is a sapphire substrate 10. The sapphire substrate 10 is a commonly used substrate 10, with mature technology and low cost. Specifically, it can be a patterned sapphire substrate 10 or a flat sapphire substrate 10.

[0081] Optionally, such as Figure 1 As shown, the first groove 201, the second groove 202, and the third groove 203 are all located at the edge of the first epitaxial layer 21. This avoids the need to create grooves in the central region of the epitaxial layer, which would affect the light emission effect of the epitaxial layer.

[0082] For example, such as Figure 1 As shown, the first groove 201 is located between the second groove 202 and the third groove 203, and the first groove 201 is located on the side of the epitaxial layer, while the second groove 202 and the third groove 203 are located at the corners of the epitaxial layer.

[0083] In other implementations of this disclosure, such as Figure 5 As shown, the light-emitting diode also includes a second electrode 52, and the first electrode 51 and the second electrode 52 are located on opposite sides of the epitaxial layer. That is, this type of light-emitting diode is a reverse polarity diode and does not have a substrate 10.

[0084] like Figure 5 As shown, the first electrode 51 is located on the surface of the second epitaxial layer 22 away from the first epitaxial layer 21, and the second electrode 52 is located on the surface of the first epitaxial layer 21 away from the second epitaxial layer 22.

[0085] In this implementation, the light-emitting diode does not require a substrate 10. The two electrodes are respectively disposed on opposite sides of the epitaxial layer. By energizing the first electrode 51 and the second electrode 52 on the two sides of the epitaxial layer, the purpose of controlling the two epitaxial layers to emit light can be achieved, which is convenient to use.

[0086] Figure 6 This is a flowchart illustrating a method for fabricating a light-emitting diode (LED) according to an embodiment of this disclosure. Figure 6 As shown, the preparation method includes:

[0087] S11: Form the first epitaxial layer 21 and the second epitaxial layer 22.

[0088] S12: Bond the first epitaxial layer 21 and the second epitaxial layer 22 to form a connection structure 30 between the first epitaxial layer 21 and the second epitaxial layer 22.

[0089] S13: A first groove 201 extending to the connection structure 30 is formed on the surface of the second epitaxial layer 22, and a conductive structure 40 is formed in the first groove 201.

[0090] The conductive structure 40 is located at least on the surface of the connecting structure 30, the surface of the second epitaxial layer 22, and within the first groove 201. The conductive structure 40 is electrically connected to the first epitaxial layer 21 through the connecting structure 30, and is also electrically connected to the second epitaxial layer 22.

[0091] The following is Figures 1 to 4 Taking the light-emitting diode shown as an example, the fabrication process of a light-emitting diode will be briefly explained.

[0092] In this embodiment of the disclosure, steps S11 to S13 may include the following steps:

[0093] The first step is to fabricate a first epitaxial layer and a second epitaxial layer 22 on a sapphire substrate 10 or a GaAs substrate 10, respectively.

[0094] The first epitaxial layer 21 and the second epitaxial layer 22 are epitaxial layers of the same emission color. For example, the first epitaxial layer 21 and the second epitaxial layer 22 can be blue light epitaxial layers.

[0095] The second step is to fabricate an ITO layer or a NiAu structure on the surface of the first epitaxial layer 21 and the second epitaxial layer 22.

[0096] The thickness of the ITO layer ranges from 50 angstroms to 5000 angstroms, while the thickness of the NiAu structure can be 20 angstroms.

[0097] Thirdly, an organic adhesive material with a thickness of 0.5 μm to 3 μm is spin-coated onto the surface of the first epitaxial layer 21 away from the substrate 10, and an organic adhesive material with a thickness of 0.5 μm to 3 μm is spin-coated onto the surface of the second epitaxial layer 22 away from the substrate 10. The second epitaxial layer 22 is then bonded to the first epitaxial layer 21 to form a bonding layer 32 between the first epitaxial layer 21 and the second epitaxial layer 22.

[0098] During the bonding process, the bonding pressure is 2000 kg to 8000 kg, and the temperature is 200 °C to 300 °C. Then, the sapphire substrate 10 or GaAs substrate 10 on the surface of the second epitaxial layer 22 is removed using laser lift-off, resulting in the following... Figure 7 The light-emitting diode shown.

[0099] Figure 8 This is a fabrication state diagram of a light-emitting diode provided in an embodiment of this disclosure. Figure 9 yes Figure 8 The provided CC cross-section diagram. Figure 10 yes Figure 8 The provided DD cross-sectional diagram.

[0100] The fourth step involves etching the two epitaxial layers onto the sapphire layer using photolithography and etching, according to the pre-designed pattern, to complete the segmentation of the light-emitting unit.

[0101] Fifth step, as Figure 8 , 9 As shown, the first groove 201 is formed by photolithography and etching according to the preset design; as Figure 8 , 10 As shown, etching forms the second groove 202 and the third groove 203.

[0102] The first groove 201 is etched to the second conductive layer 31, the second groove 202 is etched to the third conductive layer 33, and the third groove 203 is etched to the first n-type layer 211 of the first epitaxial layer 21.

[0103] Step 6, as follows Figure 1 , 2 As shown, a first insulating layer 41 is covered in a portion of the area covered in the first groove 201 and the sidewall of the second epitaxial layer 22, and a first conductive layer 42 is formed on the surface of the first insulating layer 41. The first conductive layer 42 is located at least on the surface of the second epitaxial layer 22 and the surface of the second conductive layer 31.

[0104] Step 7, as Figure 1 , 4 As shown, the second insulating layer 55 covers the entire surface of the second epitaxial layer 22, and a first through hole 53 is formed on the second insulating layer 55 of the second groove 202, and a second through hole 54 is formed on the third insulating layer of the third groove 203.

[0105] The eighth step involves fabricating and bonding the first electrode 51 and the second electrode 52 on the second insulating layer 55 using photolithography and evaporation. The first electrode 51 is connected to the second p-type layer 221 of the second epitaxial layer 22 through the second groove 202 and the first through hole 53. The second electrode 52 is connected to the first n-type layer 211 of the first epitaxial layer 21 through the third groove 203 and the second through hole 54, thereby completing the fabrication of the light-emitting diode.

[0106] In this embodiment of the disclosure, when fabricating a reverse polarity light-emitting diode, i.e., when the two electrodes are located on opposite sides of the epitaxial layer, the difference compared to fabricating a vertical structure light-emitting diode is that no third groove is provided on the second epitaxial layer. Before fabricating the second electrode, the substrate on the first epitaxial layer is removed first, and then the second electrode is formed in the area of ​​the first n-type layer exposed on the first epitaxial layer.

[0107] The light-emitting diode fabricated by this method includes a first epitaxial layer and a second epitaxial layer stacked together. The surface of the second epitaxial layer has a first groove extending to the first epitaxial layer. A conductive structure is also provided in the first groove. The conductive structure is located at least on the surface of the first epitaxial layer, the surface of the second epitaxial layer, and in the first groove, so as to connect the first epitaxial layer and the second epitaxial layer in series. In this way, when the light-emitting diode is energized, the first epitaxial layer and the second epitaxial layer can generate electricity simultaneously, thereby greatly improving the luminous brightness.

[0108] Compared to the two horizontally arranged epitaxial layers in related technologies, the two stacked epitaxial layers do not have gaps in the horizontal direction. Therefore, the two epitaxial layers can be designed according to the maximum size of the light-emitting diode, which can maximize the area of ​​the light-emitting region in the light-emitting diode, thereby improving the luminous efficiency of the light-emitting diode.

[0109] The above is not intended to limit this disclosure in any way. Although this disclosure has been disclosed above through embodiments, it is not intended to limit this disclosure. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the technical solution of this disclosure. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of this disclosure without departing from the content of the technical solution of this disclosure shall still fall within the scope of the technical solution of this disclosure.

Claims

1. A light-emitting diode, characterized in that, The light-emitting diode includes: a first epitaxial layer (21), a second epitaxial layer (22), a connection structure (30), and a conductive structure (40). The first epitaxial layer (21), the connection structure (30), and the second epitaxial layer (22) are stacked sequentially. The first epitaxial layer (21) and the second epitaxial layer (22) emit the same light color. The surface of the second epitaxial layer (22) has a first groove (201) extending to the connection structure (30). The connection structure (30) includes a second conductive layer (31), a bonding layer (32), and a third conductive layer (33) stacked sequentially on the surface of the first epitaxial layer (21). The bonding layer (32) is an insulating material layer. The first groove (201) exposes the second conductive layer (31). The conductive structure (40) is located at least on the surface of the connection structure (30), the surface of the second epitaxial layer (22), and within the first groove (201). The conductive structure (40) is electrically connected to the first epitaxial layer (21) through the second conductive layer (31), and the conductive structure (40) is electrically connected to the second epitaxial layer (22).

2. The light-emitting diode according to claim 1, characterized in that, The conductive structure (40) includes a first insulating layer (41) and a first conductive layer (42). The first insulating layer (41) is located at least within the first groove (201) and on the sidewall of the second epitaxial layer (22) and the sidewall of the connecting structure (30). The first conductive layer (42) is located at least on the surface of the connecting structure (30), the surface of the second epitaxial layer (22), and the surface of the first insulating layer (41).

3. The light-emitting diode according to claim 2, characterized in that, The first conductive layer (42) is a transparent conductive layer or a metal layer.

4. The light-emitting diode according to claim 2, characterized in that, The second conductive layer (31) and the third conductive layer (33) are both transparent conductive layers, and the first conductive layer (42) is located on the second conductive layer (31).

5. The light-emitting diode according to claim 4, characterized in that, The surface of the second epitaxial layer (22) has a second groove (202) that exposes the third conductive layer (33); The light-emitting diode further includes a first electrode (51) and a second insulating layer (55). The second insulating layer (55) is located at least on the surface of the second epitaxial layer (22), the surface of the conductive structure (40), in the first groove (201), and in the second groove (202). The second insulating layer (55) has a first through hole (53) exposing the third conductive layer (33). The first electrode (51) is located at least on the surface of the second insulating layer (55) and in the second groove (202), and is connected to the third conductive layer (33) through the first through hole (53).

6. The light-emitting diode according to claim 5, characterized in that, The light-emitting diode further includes a second electrode (52), the surface of the second epitaxial layer (22) has a third groove (203) exposing the first epitaxial layer (21), the second insulating layer (55) is located in the third groove (203), the second insulating layer (55) has a second through hole (54) exposing the first epitaxial layer (21), the second electrode (52) is at least partially located in the third groove (203), and is connected to the first epitaxial layer (21) through the second through hole (54).

7. The light-emitting diode according to claim 6, characterized in that, The first groove (201), the second groove (202) and the third groove (203) are all located at the edge of the second epitaxial layer (22).

8. The light-emitting diode according to claim 5, characterized in that, The light-emitting diode further includes a second electrode (52), which is located on the surface of the first epitaxial layer (21) away from the second epitaxial layer (22).

9. The light-emitting diode according to any one of claims 1 to 8, characterized in that, The first epitaxial layer (21) includes a first n-type layer (211), a first light-emitting layer (212) and a first p-type layer (213) stacked in sequence, and the second epitaxial layer (22) includes a second p-type layer (221), a second light-emitting layer (222) and a second n-type layer (223) stacked in sequence on the connection structure (30).

10. A method for fabricating a light-emitting diode, characterized in that, The preparation method includes: A first epitaxial layer and a second epitaxial layer are formed, and the first epitaxial layer and the second epitaxial layer emit the same color. The first epitaxial layer and the second epitaxial layer are bonded together to form a connection structure between the first epitaxial layer and the second epitaxial layer. The connection structure includes a second conductive layer, a bonding layer and a third conductive layer sequentially stacked on the surface of the first epitaxial layer. The bonding layer is an insulating material layer. A first groove extending to the connection structure is formed on the surface of the second epitaxial layer. The first groove exposes the second conductive layer. A conductive structure is formed in the first groove. The conductive structure is located at least on the surface of the connection structure, the surface of the second epitaxial layer, and in the first groove. The conductive structure is electrically connected to the first epitaxial layer through the second conductive layer and is also electrically connected to the second epitaxial layer.

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