An LED light emitting device

Abstract

The application discloses an LED light-emitting device, and belongs to the technical field of light-emitting diodes. In the LED light-emitting device, an etching edge is arranged on a first current diffusion layer close to a first electrode layer; when the LED light-emitting device is normally operated, the length of lateral current diffusion in the first current diffusion layer is smaller than the shortest distance between the edge of the first electrode layer and the etching edge, so that the working current in the first current diffusion layer cannot diffuse to the etching edge, the etching edge becomes a non-effective light-emitting area, and problems such as electric leakage, reliability reduction and yield reduction caused by device damage at the etching edge are avoided, and meanwhile, the light-emitting efficiency is improved.

Description

Technical Field

[0001] This application relates to the field of light-emitting diode technology, and in particular to an LED light-emitting device. Background Technology

[0002] Micro-LED technology miniaturizes and matrixes traditional LEDs. It first miniaturizes large-size LED chips to micrometer-scale Micro-LED chips, then matrixes them into a high-density integrated LED array. This allows each light-emitting unit in a Micro-LED display to be independently positioned and illuminated, enabling precise control of each Micro-LED chip and thus achieving display functionality. In existing technologies, etching processes are typically used to control chip size to obtain Micro-LED chips. However, etching at the chip edges damages the chip structure, causing leakage, decreased reliability, and reduced yield, negatively impacting light extraction efficiency. Summary of the Invention

[0003] The main technical problem addressed by this application is to provide an LED light-emitting device that can improve the photoelectric performance of the LED light-emitting device.

[0004] To solve the above-mentioned technical problems, one technical solution adopted in this application is: to provide an LED light-emitting device, the LED light-emitting device comprising a light-emitting epitaxial wafer, the light-emitting epitaxial wafer comprising:

[0005] Active layer;

[0006] The first current diffusion layer and the second current diffusion layer are respectively disposed on opposite sides of the active layer;

[0007] A first electrode layer and a second electrode layer, wherein the first electrode layer is disposed on the side of the first current diffusion layer opposite to the active layer, and the second electrode layer is disposed on the side of the second current diffusion layer opposite to the active layer;

[0008] The first current diffusion layer has etched edges, and its thickness and resistivity are set such that, when the LED light-emitting device is operating normally, the lateral current diffusion length of the first current diffusion layer satisfies... Where Ls is the lateral current diffusion length of the first current diffusion layer, and D1 is the shortest distance between the edge of the first electrode layer and the etched edge.

[0009] The first electrode layer includes a plurality of sub-electrodes arranged in an array, and an etched region is formed between the sub-electrodes. The etched region divides the light-emitting epitaxial wafer into a plurality of light-emitting units corresponding to the plurality of sub-electrodes, and D1 is the shortest distance between the edge of the sub-electrode and the edge of the etched region.

[0010] The etched area penetrates at least the first current diffusion layer.

[0011] The lateral current diffusion length Ls of the first current diffusion layer is calculated using the following formula:

[0012]

[0013] Where k is the Boltzmann constant, T is the thermodynamic temperature, e is the electron charge, and t is the thickness of the first current diffusion layer. The resistivity of the first current diffusion layer. The current density within the first current diffusion layer covered by the sub-electrode when the LED light-emitting device is operating normally.

[0014] The resistivity of the first current diffusion layer is greater than or equal to 0.1 Ω·cm.

[0015] The thickness of the first current diffusion layer is less than or equal to 1 μm.

[0016] Wherein, the resistivity of the first current diffusion layer is greater than or equal to 0.5 Ω·cm, and the thickness of the first current diffusion layer is less than or equal to 0.5 μm.

[0017] Wherein, the resistivity of the first current diffusion layer is greater than or equal to 1 Ω·cm, and the thickness of the first current diffusion layer is less than or equal to 0.1 μm.

[0018] in, .

[0019] in, Where D2 is the longest distance between the edge of the sub-electrode and the edge of the etched area.

[0020] The LED light-emitting device further includes a driving backplate, which includes a backplate body and a plurality of switching devices arranged in an array on the backplate body. Each of the sub-electrodes is electrically connected to the corresponding switching device so that the connected switching device provides a driving signal.

[0021] The driving backplate is bonded and fixed to the light-emitting epitaxial wafer;

[0022] The first electrode layer is formed on the backplate body and forms a conductive contact with the first current diffusion layer when the driving backplate is bonded and fixed to the light-emitting epitaxial wafer; or...

[0023] The first electrode layer is formed on the first current diffusion layer, and the driving backplane further includes a plurality of bonding electrodes arranged in an array on the backplane body. Each of the bonding electrodes is electrically connected to the corresponding switching device and is aligned and bonded to the corresponding sub-electrode.

[0024] The driving backplate is formed on one side of the light-emitting epitaxial wafer by growth.

[0025] The first electrode layer is formed on the first current diffusion layer. When the driving backplate is formed by growth, the switching device is grown and formed corresponding to the position of the sub-electrode.

[0026] The LED light-emitting device further includes a backplate substrate located on the side of the backplate body away from the first electrode layer and bonded to the backplate body.

[0027] In this configuration, one of the first current diffusion layer and the second current diffusion layer is an N-type semiconductor layer, and the other is a P-type semiconductor layer. The second electrode layer is a common electrode layer.

[0028] The beneficial effects of this application are as follows: Unlike the prior art, in the LED light-emitting device of this application, the first current diffusion layer near the first electrode layer has an etched edge. When the LED light-emitting device is working normally, the lateral current diffusion length in the first current diffusion layer is less than the shortest distance between the edge of the first electrode layer and the etched edge, so that the working current in the first current diffusion layer will not diffuse to the etched edge, making the etched edge a non-effective light-emitting area, thereby avoiding problems such as leakage, decreased reliability and decreased yield caused by device damage at the etched edge, and at the same time improving the light extraction efficiency. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Among them:

[0030] Figure 1 This is a schematic diagram of the structure of an embodiment of the LED light-emitting device of this application;

[0031] Figure 2 This is a schematic diagram of another embodiment of the LED light-emitting device of this application;

[0032] Figure 3 A schematic diagram of one embodiment of the drive backplate;

[0033] Figure 4 This is a schematic diagram of one embodiment of the extensional structure;

[0034] Figure 5 A schematic diagram of a temporary bonding implementation of an epitaxial structure;

[0035] Figure 6 A schematic diagram of one embodiment for forming the etched region;

[0036] Figure 7 A schematic diagram of a structure in which the epitaxial structure and the driving backplate are bonded together;

[0037] Figure 8 This is a schematic diagram of another embodiment of the extensional structure;

[0038] Figure 9 A schematic diagram of another embodiment of bonding the epitaxial structure to the drive backplate;

[0039] Figure 10 This is a schematic diagram of another embodiment of the LED light-emitting device of this application;

[0040] Figure 11 A schematic diagram of another embodiment for forming the etched region;

[0041] Figure 12 A schematic diagram of a structure for one embodiment of a growth-driven backplate;

[0042] Figure 13 This is a schematic diagram of another embodiment of the LED light-emitting device of this application. Detailed Implementation

[0043] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0044] Please see Figure 1 , Figure 1This is a schematic diagram of the structure of an embodiment of the LED light-emitting device of this application. The LED light-emitting device includes a light-emitting epitaxial wafer 100, which further includes an active layer 11, a first current diffusion layer 12, a second current diffusion layer 13, a first electrode layer 14, and a second electrode layer 15. The first current diffusion layer 12 and the second current diffusion layer 13 are respectively disposed on opposite sides of the active layer 11. The first electrode layer 14 is disposed on the side of the first current diffusion layer 12 facing away from the active layer 11, and the second electrode layer 15 is disposed on the side of the second current diffusion layer 13 facing away from the active layer 11. The first electrode layer 14 is used for electrical connection with a driving backplane (not shown), receiving driving signals from the driving backplane, and controlling the corresponding active layer 11 to emit light.

[0045] In this design, one of the first current diffusion layer 12 and the second current diffusion layer 13 is an N-type semiconductor layer, and the other is a P-type semiconductor layer, formed by doping semiconductor materials such as AlN, AlGaN, GaN, InGaN, AlInGaN, GaAs, GaP, GaAsP, AlGaAs, and AlGaInP. For example, the first current diffusion layer 12 is an N-type semiconductor layer, and the second current diffusion layer 13 is a P-type semiconductor layer; or, the first current diffusion layer 12 is a P-type semiconductor layer, and the second current diffusion layer 13 is an N-type semiconductor layer. The fabrication process for the LED light-emitting device of this application differs depending on the two different structures, as will be described below. The active layer 11, the first current diffusion layer 12, and the second current diffusion layer 13 can all be formed by epitaxial growth processes.

[0046] The second electrode layer 15 is a common electrode layer, such as a common electrode layer formed of materials like Al, Cr, or ITO. Preferably, the second electrode layer 15 is a transparent layer and serves as the light-emitting surface of the light-emitting epitaxial wafer 100. When the first electrode layer 14 and the second electrode layer 15 are connected to a working voltage, holes from the P-type semiconductor layer and electrons from the N-type semiconductor layer recombine in the active layer 11 to emit light. The emission wavelength is determined by the energy band structure of the semiconductor material. Figure 1 The curved arrows in the diagram represent the current diffusion inside the LED light-emitting device when the first electrode layer 14 and the second electrode layer 15 are connected to the working voltage.

[0047] The first current diffusion layer 12 has etched edges, and its thickness and resistivity are set such that, when the LED light-emitting device is operating normally, the lateral current diffusion length of the first current diffusion layer 12 satisfies... Where Ls is the lateral current diffusion length of the first current diffusion layer 12, and D1 is the shortest distance between the edge of the first electrode layer and the etched edge. This prevents the working current in the first current diffusion layer 12 from spreading to the etched edge, making the etched edge a non-effective light-emitting area. This avoids problems such as leakage, decreased reliability, and decreased yield caused by device damage at the etched edge, while also improving light extraction efficiency.

[0048] In one implementation, please refer to Figure 2 , Figure 2 This is a schematic diagram of another embodiment of the LED light-emitting device of this application. Unlike the embodiments described above, in this embodiment, the first electrode layer 14 includes a plurality of sub-electrodes 141 arranged in an array. An etched region S is formed between the sub-electrodes 141, dividing the light-emitting epitaxial wafer 100 into a plurality of light-emitting units corresponding to the plurality of sub-electrodes 141. The sub-electrodes 141 are electrically connected to the driving backplane 200, receive driving signals from the driving backplane 200, and control the active layer 11 in the corresponding light-emitting unit to emit light. Figure 2 The hollow arrows in the diagram indicate that each individual light-emitting unit emits light.

[0049] In this embodiment, the lateral current diffusion length of the first current diffusion layer 12 satisfies D1 is the shortest distance between the edge of the sub-electrode 141 and the edge of the etched region S (i.e., the etch edge). This ensures that the operating current does not diffuse to the boundary (etch edge) between the first current diffusion layer 12 and the etched region S, i.e., the edge of the first current diffusion layer 12 with etch damage becomes an ineffective light-emitting area. This avoids problems such as leakage, decreased reliability, and decreased yield caused by device damage at the etch edge, while also improving light extraction efficiency.

[0050] The etched region S penetrates at least the first current diffusion layer 12, and may also penetrate the active layer 11 and the second current diffusion layer 13. Figure 2 The etched region S is schematically shown in the case where it only penetrates the first current diffusion layer 12.

[0051] In one implementation, please refer to [link / reference needed]. Figure 1 and Figure 2 The transverse current diffusion length Ls of the first current diffusion layer 12 is calculated by the following formula (1):

[0052] ...(1);

[0053] Where k is Boltzmann's constant, T is the thermodynamic temperature, e is the electron charge, and t is the thickness of the first current diffusion layer 12. The resistivity of the first current diffusion layer 12, For the first electrode layer 14 ( when the LED light-emitting device is working normally) Figure 1 ) or sub-electrode 141 ( Figure 2 The current density within the first current diffusion layer 12 covered by the first current diffusion layer 12 is shown. It can be seen that the lateral current diffusion length Ls decreases with decreasing thickness t of the first current diffusion layer 12, and decreases with decreasing resistivity of the first current diffusion layer 12. As the current increases, the lateral current diffusion length Ls needs to be reduced in order to prevent the working current in the first current diffusion layer 12 from spreading to the etched edge.

[0054] This embodiment limits the resistivity of the first current diffusion layer 12. To achieve this, greater than or equal to 0.1 Ω·cm For example, resistivity The values ​​are 0.1Ω·cm, 0.3Ω·cm, 0.5Ω·cm, 0.7Ω·cm, 1Ω·cm, etc., which can be achieved by adjusting the parameters of the epitaxial growth process.

[0055] In one embodiment, this can also be achieved by limiting the thickness t of the first current diffusion layer 12 to be less than or equal to 1 μm. For example, the thickness t can be 1μm, 0.8μm, 0.6μm, 0.4μm, 0.2μm, 0.1μm, etc., which can be achieved by adjusting the parameters of the epitaxial growth process.

[0056] In one embodiment, the resistivity of the first current diffusion layer 12 can also be defined simultaneously. This is achieved by ensuring that the current diffusion layer 12 has a current density greater than or equal to 0.5 Ω·cm and a thickness t less than or equal to 0.5 μm. For example, resistivity The Ω·cm, 0.8Ω·cm, 1.2Ω·cm, 1.5Ω·cm, and 1.8Ω·cm are respectively, while the thickness t is 0.5μm, 0.4μm, 0.3μm, 0.2μm, and 0.1μm respectively. The specific values ​​can be achieved by adjusting the parameters of the epitaxial growth process.

[0057] In one embodiment, the resistivity of the first current diffusion layer 12 can also be defined simultaneously. To achieve a current diffusion layer 12 thickness t of less than or equal to 0.1 μm, the thickness must be greater than or equal to 1 Ω·cm. For example, resistivity The values ​​are 1Ω·cm, 1.2Ω·cm, 1.4Ω·cm, 1.6Ω·cm, 2Ω·cm, etc., while the thickness t is 0.1μm, 0.08μm, 0.06μm, 0.04μm, etc., which can be achieved by adjusting the parameters of the epitaxial growth process.

[0058] It is worth noting that the resistivity of a semiconductor layer is generally controlled by the doping rate. Generally, the higher the doping rate, the lower the resistivity (and thus the higher the conductivity). In the above embodiment, the resistivity of the first current diffusion layer 12 is much higher than that of the semiconductor used in conventional LEDs, meaning a lower doping rate is required. This does not increase the manufacturing difficulty of the LED; on the contrary, it reduces it. Furthermore, the thickness of the first current diffusion layer 12 is also much smaller than that of the semiconductor used in conventional LEDs, thereby reducing material costs.

[0059] In one embodiment, the shortest distance between the edge of the first electrode layer 14 or the sub-electrode 141 and the etch edge is... For example, 10μm, 8μm, 6μm, 4μm, 2μm, 1μm, etc. This prevents D1 from being too large, which would cause an excessive difference in size between the first electrode layer 14 and the first current diffusion layer 12 in a single light-emitting unit, making it difficult for the LED light-emitting device to work properly.

[0060] In one implementation, please refer to [link / reference needed]. Figure 2 The LED light-emitting device of this application also meets the following requirements: Where D2 is the longest distance between the edge of the sub-electrode 141 and the edge of the etched area S. This ensures that the size of the etched area S is not too small to achieve the insulating spacing between adjacent light-emitting units, and also ensures that the size of the etched area S is not too large to result in an excessively low arrangement density of light-emitting units, thus affecting the light-emitting effect of the LED light-emitting device.

[0061] In one implementation, please refer to [link / reference needed]. Figure 2 The LED light-emitting device of this application further includes a driving backplate 200, which includes a backplate body 21 and a plurality of switching devices (not shown) arranged in an array on the backplate body 21. The driving backplate 200 is bonded and fixed to the light-emitting epitaxial wafer 100, and each sub-electrode 141 is electrically connected to the corresponding switching device so that the connected switching device provides a driving signal. That is, there is a one-to-one correspondence between the switching device and the sub-electrode 141.

[0062] In the process of fabricating LED light-emitting devices, a first electrode layer 14 composed of multiple sub-electrodes 141 can be formed on the backplate body 21 corresponding to the switching device. When the driving backplate 200 is bonded to the light-emitting epitaxial wafer 100, it forms a conductive contact with the first current diffusion layer 12, i.e., the sub-electrodes 141 and the first current diffusion layer 12 are bonded together. The driving signal is directly transmitted from the switching device to the corresponding sub-electrode 141, thereby controlling the active layer 11 covered by the sub-electrode 141 to emit light, while satisfying the requirements... Based on this, the working current of the light-emitting unit will not diffuse to the etched edge, thus improving the photoelectric performance of the LED light-emitting device.

[0063] In other embodiments, the first electrode layer 14, composed of multiple sub-electrodes 141, can also be directly formed on the first current diffusion layer 12. In this case, the driving backplane 200 further includes multiple bonding electrodes (not shown) arranged in an array on the backplane body 21. Each bonding electrode is electrically connected to a corresponding switching device and is aligned and bonded to a corresponding sub-electrode 141. The driving signal is transmitted from the switching device through the bonding electrode to the corresponding sub-electrode 141, thereby controlling the active layer 11 covered by the sub-electrode 141 to emit light, while satisfying the requirements... Based on this, the working current of the light-emitting unit will not diffuse to the etched edge, thus improving the photoelectric performance of the LED light-emitting device.

[0064] The following describes the fabrication process of the LED light-emitting device of this application in two cases: when the first current diffusion layer 12 is an N-type semiconductor layer or a P-type semiconductor layer. Figure 2 Taking the LED light-emitting device shown as an example, in both cases, the switching device corresponding to the sub-electrode 141 is formed on the back plate body 21, and the driving back plate 200 and the light-emitting epitaxial sheet 100 are fixed by bonding.

[0065] First, a driver backplane is required for all of them. Please refer to the following: Figure 2 See Figure 3 , Figure 3 This is a schematic diagram of one embodiment of the driving backplate. The driving backplate 200 includes a backplate body 21 and a plurality of switching devices (not shown) arranged in an array on the backplate body 21. The plurality of sub-electrodes 141 arranged in an array in the first electrode layer 14 are also pre-connected to the corresponding switching devices. The backplate contact metal on the surface of the backplate body 21 facing the light-emitting epitaxial wafer 100 is preferably made of materials or alloys such as AlGe, Cr, Ti, Pt, Ni, Au, and Sn, with AlGe being the most suitable material due to its high reflectivity. This metal is used to reflect light from the light-emitting epitaxial wafer 100 toward the backplate body 21 to the light-emitting surface.

[0066] Additionally, the extensional structure also needs to be provided; please refer to... Figure 2 and Figure 3 See Figure 4 , Figure 4This is a schematic diagram of one embodiment of the epitaxial structure 300. The epitaxial structure 300 includes a substrate 31, a buffer layer 32, a first current diffusion layer 12, an active layer 11, and a second current diffusion layer 13. The first current diffusion layer 12 is an N-type semiconductor layer, and the second current diffusion layer 13 is a P-type semiconductor layer. Specifically, the buffer layer 32, the first current diffusion layer 12, the active layer 11, and the second current diffusion layer 13 are sequentially formed on the substrate 31 using an epitaxial process. The buffer layer 32 is used to reduce the adverse effects caused by lattice mismatch between the substrate 31 and the N-type semiconductor layer. When forming the first current diffusion layer 12, the size of the etched region S needs to be designed based on the size information of the driving backplate 200 and the sub-electrode 141, thereby designing the thickness t and resistivity of the first current diffusion layer 12. This ensures that the lateral current diffusion length of the first current diffusion layer 12 satisfies .

[0067] Next, a second electrode layer 15, such as a transparent electrode ITO, is formed on one side surface of the second current diffusion layer 13 of the epitaxial structure 300. (See [link to documentation]). Figure 5 , Figure 5 This is a schematic diagram of an embodiment of temporary bonding of the epitaxial structure. The epitaxial structure 300 is then transferred from the second electrode layer 15 side to the temporary substrate 42 via the temporary bonding layer 41. The temporary bonding layer 41 can be formed of a thermoplastic material and can be removed subsequently by high-temperature pyrolysis. Next, the substrate 31 is removed by grinding, chemical etching, laser lift-off, etc., and the buffer layer 32 is removed by dry or wet etching.

[0068] Furthermore, please combine Figure 2 and Figure 5 See Figure 6 , Figure 6 A schematic diagram of one embodiment for forming the etched region shows that the epitaxial structure 300, with the substrate 31 and buffer layer 32 removed, is etched from one side of the first current diffusion layer 12 to form an etched region S, which isolates multiple light-emitting units. The etched region S at least penetrates the first current diffusion layer 12.

[0069] Furthermore, please combine Figure 2 and Figure 6 See Figure 7 , Figure 7 This is a schematic diagram of an embodiment of bonding an epitaxial structure to a driving backplate. After forming the etched region S, the epitaxial structure 300, with the substrate 31 and buffer layer 32 removed, is bonded to the driving backplate 200 from the side of the first current diffusion layer 12. Specifically, it is bonded to the sub-electrode 141 formed on the switching device, and an ohmic contact is formed by high-temperature annealing. Then, the temporary substrate 42 and temporary bonding layer 41 are removed by high-temperature pyrolysis to obtain... Figure 2The LED light-emitting device shown in this application is an example of this application.

[0070] In another case, please refer to Figure 8 , Figure 8 This is a schematic diagram of another embodiment of the epitaxial structure. The epitaxial structure 300 includes a substrate 31, a buffer layer 32, the aforementioned second current diffusion layer 13, an active layer 11, and a first current diffusion layer 12, wherein the second current diffusion layer 13 is an N-type semiconductor layer and the first current diffusion layer 12 is a P-type semiconductor layer.

[0071] Then, an etched region S is formed on one side of the P-type semiconductor layer (i.e., the first current diffusion layer 12). The epitaxial structure 300 is then bonded from the first current diffusion layer 12 side to the driving backplate 200, specifically to the sub-electrode 141 formed on the switching device, and an ohmic contact is formed using high-temperature annealing. See details in [link to documentation]. Figure 9 , Figure 9 This is a schematic diagram of another embodiment of the bonding of the epitaxial structure to the drive backplane.

[0072] Next, the substrate 31 and the buffer layer 32 are removed sequentially, and a second electrode layer 15, such as a transparent electrode ITO, is formed on one side of the second current diffusion layer 13. To form an ohmic contact, an Al or Cr conductive layer with a thickness of less than 5 nm can be formed between the ITO and the N-type semiconductor layer (i.e., the second current diffusion layer 13), thereby obtaining the LED light-emitting device of this application. For details, please refer to the relevant reference. Figure 2 and Figure 9 .

[0073] In one implementation, please refer to Figure 10 , Figure 10 This is a schematic diagram of another embodiment of the LED light-emitting device of this application, and... Figure 2 Similar to the LED light-emitting device shown, in this embodiment, the LED light-emitting device includes a light-emitting epitaxial wafer 100, which further includes an active layer 11, a first current diffusion layer 12, a second current diffusion layer 13, a first electrode layer 14, and a second electrode layer 15. The first electrode layer 14 includes a plurality of sub-electrodes 141 arranged in an array, and an etched region S is formed between the sub-electrodes 141. The etched region S divides the light-emitting epitaxial wafer 100 into a plurality of light-emitting units corresponding to the plurality of sub-electrodes 141. The etched region S penetrates the first current diffusion layer 12 and the active layer 11. Figure 10 The hollow arrows in the diagram indicate that each individual light-emitting unit emits light.

[0074] Similar to the above embodiments, the thickness and resistivity of the first current diffusion layer 12 are set such that, when the LED light-emitting device is working normally, the lateral current diffusion length of the first current diffusion layer 12 satisfies Where Ls is the lateral current diffusion length of the first current diffusion layer 12, and D1 is the shortest distance between the edge of the sub-electrode 141 and the edge of the etched region S (i.e., the etch edge). This ensures that the operating current does not diffuse to the boundary (etch edge) between the first current diffusion layer 12 and the etched region S, i.e., the edge of the first current diffusion layer 12 with etch damage becomes an ineffective light-emitting area. This avoids problems such as leakage, decreased reliability, and decreased yield caused by device damage at the etch edge, while also improving light extraction efficiency.

[0075] The LED light-emitting device can have the above-mentioned characteristics by controlling the thickness and resistivity of the first current diffusion layer 12. For details, please refer to the above-described embodiments, which will not be repeated here.

[0076] In one implementation, please refer to [link / reference needed]. Figure 10 The LED light-emitting device further includes a driving backplate 200, which includes a backplate body 21 and a plurality of switching devices 22 arranged in an array on the backplate body 21. The driving backplate 200 is formed on one side of the light-emitting epitaxial wafer 100 by growth, and each sub-electrode 141 is electrically connected to the corresponding switching device 22 so that the connected switching device 22 provides a driving signal. That is, there is a one-to-one correspondence between the switching device 22 and the sub-electrode 141.

[0077] A first electrode layer 14, consisting of multiple sub-electrodes 141, is formed on a first current diffusion layer 12. When the drive backplate 200 is formed by growth, the switching device 22 is grown and formed corresponding to the position of the sub-electrodes 141.

[0078] In this embodiment, the LED light-emitting device further includes a backplate substrate 201 and a bonding material layer 202. The backplate substrate 201 is located on the side of the backplate body 21 away from the first electrode layer 14 and is bonded and fixed to the backplate body 21, that is, it is disposed on the side of the backplate body 21 away from the first electrode layer 14 by the bonding material layer 202.

[0079] The following explanation uses the first current diffusion layer 12 as an example, which is a P-type semiconductor layer. Figure 10 The fabrication process of the LED light-emitting device is shown.

[0080] First, provide, such as Figure 8The epitaxial structure 300 shown includes a substrate 31, a buffer layer 32, a second current diffusion layer 13, an active layer 11, and a first current diffusion layer 12. The second current diffusion layer 13 is an N-type semiconductor layer, and the first current diffusion layer 12 is a P-type semiconductor layer. Specifically, the buffer layer 32, the second current diffusion layer 13, the active layer 11, and the first current diffusion layer 12 are epitaxially grown sequentially on the substrate 31. Then, an array of sub-electrodes 141 are formed on the first current diffusion layer 12, and an etched region S is formed on the first current diffusion layer 12 to define multiple light-emitting units. The sub-electrodes 141 form an ohmic contact with the first current diffusion layer 12 and include a highly reflective surface to reflect light from the active layer 11 towards the sub-electrodes 141 in the light-emitting direction. The sub-electrodes 141 can be designed as a two-layer stacked structure using the lower insulating layer 211a to increase the flexibility of the spatial redistribution of the sub-electrodes 141. For details, please refer to [reference needed]. Figure 11 , Figure 11 A schematic diagram of another embodiment for forming the etched region.

[0081] Then, please combine Figure 11 See Figure 12 , Figure 12 This is a schematic diagram of one embodiment of the growth and formation of a driving backplate. A backplate body 21 and a switching device 22 of the driving backplate 200 are grown and formed on one side of the sub-electrode 141, wherein the switching device 22 corresponds to the position of the sub-electrode 141. The backplate body 21 includes an insulating layer 211 and a polysilicon layer 212. The insulating layer 211 includes a lower insulating layer 211a (i.e.,...) that fills the etched region S. Figure 11 The lower insulating layer 211a and the upper insulating layer 211b, which are already formed in the middle, are used to isolate the multiple sub-electrodes 141 and to isolate the first current diffusion layer 12 from the polysilicon layer 212. The polysilicon layer 212 includes the functional layers forming the TFT, as is the case in the prior art, and will not be described again here. A bonding material layer 202 is used to bond and fix the driving backplate 200 to the backplate substrate 201 on one side of the driving backplate 200, thereby supporting the other layers and improving the strength and lifespan of the LED light-emitting device.

[0082] Then, please combine Figure 12 Continue reading Figure 10 ,Will Figure 12 The structure is flipped, and the substrate 31 is removed by grinding, chemical etching, laser lift-off, etc., and the buffer layer 32 is removed by dry or wet etching. Next, a second electrode layer 15, such as a transparent electrode ITO, is formed on the surface of the second current diffusion layer 13, resulting in... Figure 10 The LED light-emitting device shown.

[0083] Of course, the first current diffusion layer 12 can also be an N-type semiconductor layer. The preparation process can be found in the above embodiments, and will not be illustrated in detail here.

[0084] In one implementation, please refer to Figure 13 , Figure 13 This is a schematic diagram of another embodiment of the LED light-emitting device of this application. Figure 2 Based on the structure shown, this embodiment of the LED light-emitting device also includes a light-blocking member 500, located between adjacent sub-electrodes 141. As mentioned earlier, the light emission of each light-emitting unit corresponding to each sub-electrode 141 can be independently controlled; however, light crosstalk may occur between adjacent light-emitting units, affecting the display effect. The light-blocking member 500 has a highly reflective surface, which can reflect light that is about to enter the area of ​​an adjacent light-emitting unit back into the area of ​​the current light-emitting unit, thereby improving the light crosstalk phenomenon and enhancing the display effect.

[0085] The light-blocking component 500 can be made directly from a highly reflective metal, or an insulating transparent dielectric layer can be formed first, and then a highly reflective metal can be plated to cover the surface of the dielectric layer. The shape of the light-blocking component 500 can be rectangular, trapezoidal, triangular, etc., which can improve light crosstalk while also adjusting the light emission angle. Figure 13 Draw one of the scenarios schematically.

[0086] For further information, please refer to [link / reference]. Figure 13 The LED light-emitting device of this application also includes an adjustment element 600, which is located between adjacent light-blocking elements 500, that is, it is set for each light-emitting unit. Specifically, it can be formed by using SU8 material (a negative epoxy photoresist) to form a lens, which can improve the light emission angle of each pixel and increase the light emission efficiency.

[0087] Of course, the aforementioned light-blocking component 500 and / or adjusting component 600 can also be provided in... Figure 1 and Figure 10 The LED light-emitting device shown achieves the purpose of improving light crosstalk, enhancing display effect, improving light emission angle, and increasing light emission efficiency. Further illustrations are not provided here.

[0088] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. An LED light emitting device, characterized by, The LED light-emitting device includes a light-emitting epitaxial wafer, which comprises: Active layer; The first current diffusion layer and the second current diffusion layer are respectively disposed on opposite sides of the active layer; A first electrode layer and a second electrode layer, wherein the first electrode layer is disposed on the side of the first current diffusion layer opposite to the active layer, and the second electrode layer is disposed on the side of the second current diffusion layer opposite to the active layer; The first current diffusion layer has an etching edge, and the thickness and resistivity of the first current diffusion layer are set so that, when the LED light emitting device is normally working, the lateral current diffusion length of the first current diffusion layer satisfies wherein Ls is the lateral current diffusion length of the first current diffusion layer, and D1 is the shortest distance between the edge of the first electrode layer and the etching edge. The lateral current diffusion length Ls of the first current diffusion layer is calculated using the following formula: wherein k is the Boltzmann constant, T is the thermodynamic temperature, e is the electronic charge, t is the thickness of the first current spreading layer, and is the resistivity of the first current spreading layer, and is the current density in the first current spreading layer covered by the first electrode layer when the LED light emitting device is working normally.

2. The LED light emitting device of claim 1, wherein, The first electrode layer includes a plurality of sub-electrodes arranged in an array, and an etched region is formed between the sub-electrodes. The etched region divides the light-emitting epitaxial wafer into a plurality of light-emitting units corresponding to the plurality of sub-electrodes, and D1 is the shortest distance between the edge of the sub-electrode and the edge of the etched region.

3. The LED light emitting device of claim 2, wherein, The etched area extends at least through the first current diffusion layer.

4. The LED light emitting device of claim 2, wherein, The is the current density in the first current spreading layer covered by the sub-electrode when the LED light emitting device is working normally.

5. The LED light emitting device of claim 2, wherein, The resistivity of the first current diffusion layer is greater than or equal to 0.1 Ω·cm.

6. The LED light emitting device of claim 5, wherein, The thickness of the first current diffusion layer is less than or equal to 1 μm.

7. The LED light emitting device of claim 6, wherein, The resistivity of the first current diffusion layer is greater than or equal to 0.5 Ω·cm, and the thickness of the first current diffusion layer is less than or equal to 0.5 μm.

8. The LED light emitting device of claim 6, wherein, The resistivity of the first current diffusion layer is greater than or equal to 1 Ω·cm, and the thickness of the first current diffusion layer is less than or equal to 0.1 μm.

9. The LED light emitting device of claim 1 or 2, wherein, 。 10. The LED light emitting device of claim 2, wherein, where D2 is the longest distance between the edge of the sub-electrode to the edge of the etched region.

11. The LED light emitting device of claim 2, wherein, The LED light-emitting device further includes a driving backplate, which includes a backplate body and a plurality of switching devices arranged in an array on the backplate body, wherein each of the sub-electrodes is electrically connected to the corresponding switching device so that the connected switching device provides a driving signal.

12. The LED light emitting device of claim 11, wherein, The driving backplate is bonded and fixed to the light-emitting epitaxial sheet; The first electrode layer is formed on the backplate body and forms a conductive contact with the first current diffusion layer when the driving backplate is bonded and fixed to the light-emitting epitaxial wafer. or, The first electrode layer is formed on the first current diffusion layer, and the driving backplane further includes a plurality of bonding electrodes arranged in an array on the backplane body. Each of the bonding electrodes is electrically connected to the corresponding switching device and is aligned and bonded to the corresponding sub-electrode.

13. The LED light emitting device of claim 11, wherein, The driving backplate is formed on one side of the light-emitting epitaxial wafer by growth. The first electrode layer is formed on the first current diffusion layer. When the driving backplate is formed by growth, the switching device is grown and formed corresponding to the position of the sub-electrode. The LED light-emitting device further includes a backplate substrate located on the side of the backplate body away from the first electrode layer and bonded to the backplate body.

14. The LED light emitting device of claim 1, wherein, One of the first current diffusion layer and the second current diffusion layer is an N-type semiconductor layer and the other is a P-type semiconductor layer, and the second electrode layer is a common electrode layer.

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