Light-emitting diode and light-emitting diode preparation method

Abstract

The invention provides a light emitting diode and a light emitting diode preparation method. The light-emitting diode comprises an epitaxial structure, a transparent conductive layer, a first electrode and a second electrode, the epitaxial structure is provided with a step structure, the first electrode is located on the step bottom surface of the step structure, the transparent conductive layer is located on the step top surface of the step structure, and the second electrode is located on the transparent conductive layer; the distance from the edge of the transparent conductive layer to the edge of the step top surface of the step structure is larger than 0 and smaller than a first threshold value, and the first threshold value is in positive correlation with the total area of the step top surface and the step bottom surface of the step structure. Light shielding of the edge of the transparent conducting layer is reduced, and light transmission of the light-emitting diode is facilitated. Meanwhile, the current concentration of the transparent conducting layer is increased, and light emitting is increased.

Description

Technical Field

[0001] The present disclosure relates to the field of light-emitting devices, and in particular to a light-emitting diode and a method for preparing the light-emitting diode. Background Art

[0002] Light Emitting Diode (LED) is a semiconductor device that can emit light. It is widely used in lighting, display technology, medical equipment, plant growth lamps and other fields.

[0003] The related art provides a light emitting diode, wherein the light emitting diode structure includes an epitaxial structure, a transparent conductive layer, a first electrode and a second electrode.

[0004] In the related art, the transparent conductive layer area is too large and the current density is too low. The transparent conductive layer at the edge cannot play the role of current expansion and affects the light transmission and the brightness of the product. Summary of the invention

[0005] The embodiments of the present disclosure provide a light emitting diode and a method for manufacturing the light emitting diode, which are beneficial to improving the brightness of the light emitting diode. The technical solution is as follows:

[0006] In one aspect, an embodiment of the present disclosure provides a light emitting diode, the light emitting diode comprising:

[0007] An epitaxial structure, a transparent conductive layer, a first electrode and a second electrode;

[0008] The epitaxial structure is provided with a step structure, the step structure includes a step bottom surface and a step top surface, the first electrode is located on the step bottom surface of the step structure, the transparent conductive layer is located on the step top surface of the step structure, and the second electrode is located on the transparent conductive layer;

[0009] The distance from the edge of the transparent conductive layer to the edge of the step top surface of the step structure is greater than 0 and less than a first threshold value, and the first threshold value is positively correlated with the total area of ​​the step top surface and the step bottom surface of the step structure.

[0010] Optionally, the first threshold is no greater than 1.5% of the total area of ​​the step top surface and the step bottom surface of the step structure.

[0011] Optionally, the total area of ​​the step top surface and the step bottom surface of the step structure is less than or equal to 400 μm 2 , the distance from the edge of the transparent conductive layer to the edge of the top surface of the step structure is 3 to 5 μm;

[0012] The total area of ​​the step top and step bottom of the step structure is greater than 400 μm 2 And less than or equal to 600μm2 , the distance from the edge of the transparent conductive layer to the edge of the top surface of the step structure is 4 to 6 μm;

[0013] The total area of ​​the step top and step bottom of the step structure is greater than 600 μm 2 And less than or equal to 800μm 2 , the distance from the edge of the transparent conductive layer to the edge of the top surface of the step structure is 5 to 7 μm;

[0014] The total area of ​​the step top surface and the step bottom surface of the step structure is greater than 800 μm 2 And less than or equal to 1000μm 2 , the distance from the edge of the transparent conductive layer to the edge of the top surface of the step structure is 7 to 9 μm;

[0015] The total area of ​​the step top and step bottom of the step structure is greater than 1000 μm 2 The distance from the edge of the transparent conductive layer to the edge of the top surface of the step structure is 9 to 11 μm.

[0016] Optionally, four corners of the transparent conductive layer are arc-shaped.

[0017] Optionally, the radius of the arc is positively correlated with the total area of ​​the step top surface and the step bottom surface of the step structure.

[0018] Optionally, the total area of ​​the step top surface and the step bottom surface of the step structure is less than or equal to 400 μm 2 , the radius of the arc is 20 to 30 μm;

[0019] The total area of ​​the step top and step bottom of the step structure is greater than 400 μm 2 And less than or equal to 600μm 2 , the radius of the arc is 20 to 30 μm;

[0020] The total area of ​​the step top surface and the step bottom surface of the step structure is greater than 600 and less than or equal to 800 μm 2 , the radius of the arc is 20 to 40 μm;

[0021] The total area of ​​the step top surface and the step bottom surface of the step structure is greater than 800 and less than or equal to 1000 μm 2 , the radius of the arc is 20 to 40 μm;

[0022] The total area of ​​the step top and step bottom of the step structure is greater than 1000 μm 2 , the radius of the arc is 30 to 50 μm.

[0023] In another aspect, an embodiment of the present disclosure provides a method for preparing a light emitting diode, the method comprising:

[0024] Manufacturing an epitaxial structure, wherein the epitaxial structure is provided with a step structure, wherein the step structure comprises a step bottom surface and a step top surface;

[0025] Manufacturing a transparent conductive layer, wherein the transparent conductive layer is located on the top surface of the step of the step structure, and the distance from the edge of the transparent conductive layer to the edge of the top surface of the step of the step structure is greater than 0 and less than a first threshold value, and the first threshold value is positively correlated with the total area of ​​the top surface and the bottom surface of the step of the step structure;

[0026] A first electrode and a second electrode are manufactured, wherein the first electrode is located on the bottom surface of the step structure, and the second electrode is located on the transparent conductive layer.

[0027] Optionally, the step of preparing the transparent conductive layer includes:

[0028] Sputtering a layer of ITO film;

[0029] forming a mask pattern on the ITO film;

[0030] Under the shielding of the mask pattern, the ITO film is patterned to obtain the transparent conductive layer.

[0031] Optionally, the first threshold is no greater than 1.5% of the total area of ​​the step top surface and the step bottom surface of the step structure.

[0032] Optionally, four corners of the transparent conductive layer are arc-shaped.

[0033] The technical solution provided by the embodiments of the present disclosure has the following beneficial effects:

[0034] In the disclosed embodiment, a transparent conductive layer is arranged on the top surface of the step structure for current expansion, and the distance from the edge of the transparent conductive layer to the edge of the top surface of the step structure is greater than 0, that is, the edge area of ​​the transparent conductive layer is reduced, and the light is avoided from being blocked by the edge area of ​​the transparent conductive layer, which is conducive to the light transmission of the light-emitting diode. At the same time, the distance from the edge of the transparent conductive layer to the edge of the top surface of the step structure is less than the first threshold, and the first threshold value is positively correlated with the total area of ​​the top surface of the step and the bottom surface of the step, that is, appropriately reducing the area of ​​the transparent conductive layer can increase the current concentration of the transparent conductive layer and increase the light extraction efficiency. In addition, the distance from the edge of the transparent conductive layer to the edge of the top surface of the step structure is less than the threshold, which avoids the area of ​​the transparent conductive layer being too small to affect the current expansion effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, 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 disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0036] Figure 1 is a structural schematic diagram of a light emitting diode provided by an embodiment of the present disclosure;

[0037] Figure 2 is a top view of a light emitting diode provided by an embodiment of the present disclosure;

[0038] Figure 3 is a flow chart of a method for preparing a light emitting diode provided by an embodiment of the present disclosure;

[0039] Figure 4 A flow chart of another method for preparing a light emitting diode provided in an embodiment of the present disclosure.

[0040] The reference numerals are as follows:

[0041] 100: substrate; 101: epitaxial structure; 102: transparent conductive layer; 103: first electrode; 104: second electrode; 105: current blocking layer; 106: passivation layer;

[0042] 201: first semiconductor layer; 202: active layer; 203: second semiconductor layer;

[0043] 1011: Step structure. DETAILED DESCRIPTION

[0044] In order to make the objectives, technical solutions and advantages of the present disclosure more clear, the embodiments of the present disclosure will be further described in detail below with reference to the accompanying drawings.

[0045] Figure 1 A schematic diagram of the structure of a light emitting diode provided by an embodiment of the present disclosure. Figure 1 The light emitting diode includes: an epitaxial structure 101 , a transparent conductive layer 102 , a first electrode 103 and a second electrode 104 .

[0046] The epitaxial structure 101 is provided with a step structure 1011 , which includes a step bottom surface and a step top surface. The first electrode 103 is located at the step bottom surface of the step structure 1011 , the transparent conductive layer 102 is located at the step top surface of the step structure 1011 , and the second electrode 104 is located on the transparent conductive layer 102 .

[0047] Figure 2 is a top view of a light emitting diode provided by an embodiment of the present disclosure, see Figure 2, the distance from the edge of the transparent conductive layer 102 to the edge of the step top surface of the step structure 1011 is greater than 0 and less than a first threshold, and the first threshold is positively correlated with the total area of ​​the step top surface and the step surface of the step structure 1011.

[0048] In the disclosed embodiment, a transparent conductive layer is arranged on the top surface of the step structure for current expansion, and the distance from the edge of the transparent conductive layer to the edge of the top surface of the step structure is greater than 0, that is, the edge area of ​​the transparent conductive layer is reduced, and the light is avoided from being blocked by the edge area of ​​the transparent conductive layer, which is conducive to the light transmission of the light-emitting diode. At the same time, the distance from the edge of the transparent conductive layer to the edge of the top surface of the step structure is less than the first threshold, and the first threshold value is positively correlated with the total area of ​​the top surface of the step and the bottom surface of the step, that is, appropriately reducing the area of ​​the transparent conductive layer can increase the current concentration of the transparent conductive layer and increase the light extraction efficiency. In addition, the distance from the edge of the transparent conductive layer to the edge of the top surface of the step structure is less than the threshold, which avoids the area of ​​the transparent conductive layer being too small to affect the current expansion effect.

[0049] In the embodiment of the present disclosure, the transparent conductive layer 102 may be an indium tin oxide (ITO) layer. ITO has good transparency and conductivity and can conduct current to form an electrical connection while allowing light to pass through.

[0050] In the embodiment of the present disclosure, the first threshold is no greater than 1.5% of the total area of ​​the step top surface and the step surface of the step structure 1011, which can avoid blocking the light in the edge area of ​​the transparent conductive layer and facilitate the light from the light emitting diode to pass through.

[0051] Here, “not greater than” means that the first threshold is not greater than 1.5% of the total area value, and does not involve units. For example, if the first threshold is x μm, the total area is y μm. 2 , x is not greater than 1.5% of y.

[0052] In a possible implementation of the present disclosure, the transparent conductive layer 102 may be a rounded rectangle, and a notch corresponding to the step surface is formed on the rounded rectangle.

[0053] That is, the four corners of the transparent conductive layer 102 are arc-shaped. Arc-shaped four corners of the transparent conductive layer can reduce the light shielding area, which can effectively improve the brightness of the light-emitting diode, and the arc shape can also make the current spread more uniform.

[0054] In other possible implementations, the transparent conductive layer 102 may also be in other shapes, such as a rectangle without rounded corners, or other polygons with rounded corners.

[0055] In the embodiment of the present disclosure, the radius of the arc of the transparent conductive layer 102 is positively correlated with the total area of ​​the step top surface and the step surface of the step structure 1011 .

[0056] In the embodiment of the present disclosure, the larger the radius of the arc is, the more the area of ​​the transparent conductive layer 102 is reduced. Therefore, the radius of the arc of the transparent conductive layer 102 is positively correlated with the top surface of the step structure 1011 and the total area of ​​the step surface, so that the larger the transparent conductive layer 102 is, the more edge areas can be transparent to ensure light extraction.

[0057] In the embodiment of the present disclosure, the total area of ​​the step top surface and the step bottom surface of the step structure 1011 is less than or equal to 400 μm 2 The distance from the edge of the transparent conductive layer 102 to the edge of the step top surface of the step structure 1011 is 3-5 μm, and the radius of the arc is 20-30 μm. By adopting the above distance and arc radius design, the step top surface of the step structure 1011 and the total area of ​​the step top surface can be within 400 μm. 2 And below, the brightness is good and the voltage is not too large.

[0058] Exemplarily, the total area of ​​the step top surface and the step bottom surface of the step structure 1011 is less than or equal to 400 μm 2 The distance from the edge of the transparent conductive layer 102 to the edge of the top surface of the step structure 1011 is 4 μm, and the radius of the arc is 20 μm.

[0059] Table 1 below shows a light emitting diode step structure provided by an embodiment of the present disclosure, wherein the total area of ​​the step top surface and the step surface is less than or equal to 400 μm 2 Brightness comparison table of different transparent conductive layer designs. Wherein, VF is voltage, unit V; lv is brightness, unit mW; △lv is brightness difference, △Vf is voltage difference.

[0060] It can be seen from Table 1 below that when the distance from the edge of the transparent conductive layer to the edge of the epitaxial structure is 4 μm and the radius of the four corner arcs is 20 μm, the brightness is greater than that of other control groups and the voltage is relatively low.

[0061] Table 1

[0062]

[0063] In the embodiment of the present disclosure, the total area of ​​the step top surface and the step bottom surface of the step structure 1011 is greater than 400 μm 2 And less than or equal to 600μm 2The distance from the edge of the transparent conductive layer 102 to the edge of the step top surface of the step structure 1011 is 4-6 μm, and the radius of the arc is 20-30 μm. By adopting the above distance and arc radius design, the total area of ​​the step top surface and the step bottom surface of the step structure 1011 can be greater than 400 μm. 2 And less than or equal to 600μm 2 When the brightness is good, the voltage will not be too large.

[0064] Exemplarily, the step top surface of the step structure 1011 and the total area of ​​the step top surface are greater than 400 μm 2 And less than or equal to 600μm 2 The distance from the edge of the transparent conductive layer 102 to the edge of the top surface of the step structure 1011 is 5 μm, and the radius of the arc is 20 μm.

[0065] Table 2 below shows a total area of ​​the top and bottom surfaces of a step structure of a light-emitting diode provided by an embodiment of the present disclosure, which is greater than 400 μm 2 And less than or equal to 600μm 2 Brightness comparison table of different transparent conductive layer designs. Wherein, VF is voltage, unit V; lv is brightness, unit mW; △lv is brightness difference, △Vf is voltage difference.

[0066] It can be seen from Table 2 below that the distance from the edge of the transparent conductive layer to the edge of the epitaxial structure is 5 μm. When the radius of the four corner arcs is 20 μm, the brightness is greater than that of other control groups and the voltage is relatively low.

[0067] Table 2

[0068]

[0069] In the embodiment of the present disclosure, the total area of ​​the step top surface and the step bottom surface of the step structure 1011 is greater than 600 μm 2 And less than or equal to 800μm 2 The distance from the edge of the transparent conductive layer 102 to the edge of the step top surface of the step structure 1011 is 5 to 7 μm, and the radius of the arc is 20 to 40 μm. By adopting the above distance and arc radius design, the total area of ​​the step top surface and the step bottom surface of the step structure 1011 can be greater than 600 μm. 2 And less than or equal to 800μm 2 When the brightness is good, the voltage will not be too large.

[0070] Exemplarily, the step top surface of the step structure 1011 and the total area of ​​the step top surface are greater than 600 μm 2 And less than or equal to 800μm 2The distance from the edge of the transparent conductive layer 102 to the edge of the top surface of the step structure 1011 is 6 μm, and the radius of the arc is 30 μm.

[0071] Table 3 below shows a total area of ​​the top and bottom surfaces of a step structure 1011 of a light emitting diode provided by an embodiment of the present disclosure. 2 And less than or equal to 800μm 2 Brightness comparison table of different transparent conductive layer designs. Wherein, VF is voltage, unit V; lv is brightness, unit mW; △lv is brightness difference, △Vf is voltage difference.

[0072] It can be seen from Table 3 below that the distance from the edge of the transparent conductive layer to the edge of the epitaxial structure is 6 μm. When the radius of the four corner arcs is 30 μm, the brightness is greater than that of other control groups and the voltage is relatively low.

[0073] Table 3

[0074]

[0075] In the embodiment of the present disclosure, the total area of ​​the step top surface and the step bottom surface of the step structure 1011 is greater than 800 μm 2 And less than or equal to 1000μm 2 The distance from the edge of the transparent conductive layer 102 to the edge of the step top surface of the step structure 1011 is 7-9 μm, and the radius of the arc is 20-40 μm. By adopting the above distance and arc radius design, the total area of ​​the step top surface and the step bottom surface of the step structure 1011 can be greater than 800 μm. 2 And less than or equal to 1000μm 2 When the brightness is good, the voltage will not be too large.

[0076] Exemplarily, the step top surface of the step structure 1011 and the total area of ​​the step top surface are greater than 800 μm 2 And less than or equal to 1000μm 2 The distance from the edge of the transparent conductive layer 102 to the edge of the top surface of the step structure 1011 is 8 μm, and the radius of the arc is 30 μm.

[0077] Table 4 below shows a total area of ​​the top and bottom surfaces of a step structure of a light-emitting diode provided by an embodiment of the present disclosure, which is greater than 800 μm 2 And less than or equal to 1000μm 2 Brightness comparison table of different transparent conductive layer designs. Wherein, VF is voltage, unit V; lv is brightness, unit mW; △lv is brightness difference, △Vf is voltage difference.

[0078] It can be seen from Table 4 below that the distance from the edge of the transparent conductive layer to the edge of the epitaxial structure is 8 μm. When the radius of the four corner arcs is 30 μm, the brightness is greater than that of other control groups and the voltage is relatively low.

[0079] Table 4

[0080]

[0081]

[0082] In the embodiment of the present disclosure, the total area of ​​the step top surface and the step bottom surface of the step structure 1011 is greater than or equal to 1000 μm 2 The distance from the edge of the transparent conductive layer 102 to the edge of the step top surface of the step structure 1011 is 9-11 μm, and the radius of the arc is 30-50 μm. By adopting the above distance and arc radius design, the total area of ​​the step top surface and the step bottom surface of the step structure 1011 can be greater than or equal to 1000 μm. 2 When the brightness is good, the voltage will not be too large.

[0083] Exemplarily, the top surface of the step structure 1011 and the total area of ​​the top surface of the step are greater than or equal to 1000 μm 2 The distance from the edge of the transparent conductive layer 102 to the edge of the top surface of the step structure 1011 is 10 μm, and the radius of the arc is 40 μm.

[0084] Table 5 below shows a total area of ​​the top and bottom surfaces of a step structure of a light-emitting diode provided by an embodiment of the present disclosure, which is greater than 1000 μm 2 The brightness comparison table of the above transparent conductive layer with different designs is shown in the figure. Among them, VF is the voltage, unit is V; lv is the brightness, unit is mW; △lv is the brightness difference, and △Vf is the voltage difference.

[0085] It can be seen from Table 5 below that the distance from the edge of the transparent conductive layer to the edge of the epitaxial structure is 10 μm, and the radius of the four corner arcs is 40 μm.

[0086] Table 5

[0087]

[0088] See also Figure 1 , the light emitting diode may further include a substrate 100 .

[0089] In the embodiment of the present disclosure, the epitaxial structure 101 includes a first semiconductor layer 201 , an active layer 202 and a second semiconductor layer 203 .

[0090] The first semiconductor layer 201 , the active layer 202 and the second semiconductor layer 203 are sequentially stacked on the substrate 100 . The step surface of the step structure 1011 is located in the first semiconductor layer 201 .

[0091] In the embodiment of the present disclosure, the first semiconductor layer 201 may be an N-type semiconductor layer, and the second semiconductor layer 203 may be a P-type semiconductor layer.

[0092] In the embodiment of the present disclosure, the active layer 202 may be a multi-quantum well layer, such as an InGaN / GaN multi-quantum well layer.

[0093] For example, the first semiconductor layer 201 may be an N-type GaN layer, and the second semiconductor layer 203 may be a P-type GaN layer.

[0094] In other embodiments, the first semiconductor layer 201 may be a P-type semiconductor layer, and the second semiconductor layer 203 may be an N-type semiconductor layer.

[0095] In the embodiment of the present disclosure, the first electrode 103 and the second electrode 104 may be AuGe / Au electrodes or AuBe / Au electrodes.

[0096] Exemplarily, the first electrode 103 is an AuBe / Au electrode, and the second electrode 104 is an AuGe / Au electrode.

[0097] like Figure 1 As shown, the light emitting diode may further include a current blocking layer 105 , and the current blocking layer 105 is located between the epitaxial structure 101 and the transparent conductive layer 102 .

[0098] In the embodiment of the present disclosure, the current blocking layer 105 may be an AlGaN layer or a SiO 2 layer.

[0099] Exemplarily, the current blocking layer 105 is an AlGaN layer.

[0100] like Figure 1 As shown, the light emitting diode may further include a passivation layer 106 , and the passivation layer 106 covers the substrate 100 , the epitaxial structure 101 and the transparent conductive layer 102 .

[0101] In the embodiment of the present disclosure, the passivation layer 106 may be a SiO 2 layer.

[0102] like Figure 2 As shown, in the embodiment of the present disclosure, the first electrode 103 and the second electrode 104 may include an electrode body and an extension portion connected to the electrode body.

[0103] It is worth noting that in the embodiments of the present disclosure, structures may be selectively increased or decreased based on the structure of the above-mentioned light emitting diode, and the present disclosure does not impose any limitation on this.

[0104] Figure 3 is a flow chart of a method for preparing a light emitting diode provided by an embodiment of the present disclosure. Figure 3 The method steps include:

[0105] S11, manufacturing an epitaxial structure, wherein the epitaxial structure is provided with a step structure, and the step structure comprises a step bottom surface and a step top surface.

[0106] S12. Produce a transparent conductive layer, wherein the transparent conductive layer is located on the top surface of the step of the step structure, and the distance from the edge of the transparent conductive layer to the edge of the top surface of the step of the step structure is greater than 0 and less than a first threshold value, and the first threshold value is positively correlated with the total area of ​​the top surface and the bottom surface of the step of the step structure.

[0107] S13, manufacturing a first electrode and a second electrode, wherein the first electrode is located on a bottom surface of the step structure, and the second electrode is located on the transparent conductive layer.

[0108] In the disclosed embodiment, a transparent conductive layer is arranged on the top surface of the step structure for current expansion, and the distance from the edge of the transparent conductive layer to the edge of the top surface of the step structure is greater than 0, that is, the edge area of ​​the transparent conductive layer is reduced, and the light is avoided from being blocked by the edge area of ​​the transparent conductive layer, which is conducive to the light transmission of the light-emitting diode. At the same time, the distance from the edge of the transparent conductive layer to the edge of the top surface of the step structure is less than the first threshold, and the first threshold value is positively correlated with the total area of ​​the top surface of the step and the bottom surface of the step, that is, appropriately reducing the area of ​​the transparent conductive layer can increase the current concentration of the transparent conductive layer and increase the light extraction efficiency. In addition, the distance from the edge of the transparent conductive layer to the edge of the top surface of the step structure is less than the threshold, which avoids the area of ​​the transparent conductive layer being too small to affect the current expansion effect.

[0109] Figure 4 Another light emitting diode manufacturing method provided by the present disclosure is a flow chart. Figure 4 The method steps include:

[0110] S21. Forming a first semiconductor layer, an active layer, and a second semiconductor layer in sequence on a substrate, wherein the first semiconductor layer, the active layer, and the second semiconductor layer constitute an epitaxial structure.

[0111] In the embodiment of the present disclosure, the first semiconductor layer may be an N-type semiconductor layer, and the second semiconductor layer may be a P-type semiconductor layer.

[0112] In the embodiment of the present disclosure, the active layer may be a multi-quantum well layer.

[0113] For example, the first semiconductor layer may be an N-type GaN layer, and the second semiconductor layer may be a P-type GaN layer.

[0114] In other embodiments, the first semiconductor layer may be a P-type semiconductor layer, and the second semiconductor layer may be an N-type semiconductor layer.

[0115] S22, performing graphic processing on the epitaxial structure to form a step structure, wherein the step structure includes a step bottom surface and a step top surface.

[0116] In one example, step S22 includes:

[0117] In the embodiment of the present disclosure, an etching technology is used to pattern the first semiconductor layer, the active layer, and the second semiconductor layer stacked in sequence to form a step structure.

[0118] S23, making a current blocking layer on the top surface of the step.

[0119] In the embodiment of the present disclosure, the current blocking layer may be an AlGaN or SiO2 layer.

[0120] Exemplarily, the current blocking layer is an AlGaN current blocking layer.

[0121] S24, making a transparent conductive layer on the top surface of the step, wherein the transparent conductive layer covers the current blocking layer.

[0122] Step S24 may include:

[0123] Sputtering a layer of ITO film;

[0124] forming a mask pattern on the ITO film;

[0125] Under the protection of the mask pattern, the ITO film is patterned to obtain a transparent conductive layer.

[0126] The mask pattern can be obtained by coating a photoresist and then exposing and developing the same.

[0127] In this implementation, the distance from the edge of the transparent conductive layer to the edge of the step top surface of the step structure is greater than 0, that is, the edge area of ​​the transparent conductive layer is reduced, and the light is blocked by the edge area of ​​the transparent conductive layer, which is conducive to the light transmission of the light emitting diode. At the same time, the distance from the edge of the transparent conductive layer to the edge of the step top surface of the step structure is less than the first threshold, and the first threshold value is positively correlated with the total area of ​​the step top surface and the step bottom surface, that is, appropriately reducing the area of ​​the transparent conductive layer can increase the current concentration of the transparent conductive layer and increase the light extraction efficiency. In addition, the distance from the edge of the transparent conductive layer to the edge of the step top surface of the step structure is less than the threshold, which avoids the area of ​​the transparent conductive layer being too small and affecting the current expansion effect. Among them, the four corners of the transparent conductive layer are arc-shaped, and the arc shape can reduce the shading area, which can effectively improve the brightness of the light emitting diode, and the arc shape can also make the current expansion more uniform.

[0128] In the embodiment of the present disclosure, the first threshold is no greater than 1.5% of the total area of ​​the step top surface and the step surface of the step structure 1011, which can avoid blocking the light in the edge area of ​​the transparent conductive layer and facilitate the light from the light emitting diode to pass through.

[0129] Here, “not greater than” means that the first threshold is not greater than 1.5% of the total area value, and does not involve units. For example, if the first threshold is x μm, the total area is y μm. 2 , x is not greater than 1.5% of y.

[0130] In a possible implementation of the present disclosure, the transparent conductive layer 102 may be a rounded rectangle, and a notch corresponding to the step surface is formed on the rounded rectangle.

[0131] That is, the four corners of the transparent conductive layer 102 are arc-shaped. Arc-shaped four corners of the transparent conductive layer can reduce the light shielding area, which can effectively improve the brightness of the light-emitting diode, and the arc shape can also make the current spread more uniform.

[0132] In other possible implementations, the transparent conductive layer 102 may also be in other shapes, such as a rectangle without rounded corners, or other polygons with rounded corners.

[0133] In the embodiment of the present disclosure, the radius of the arc of the transparent conductive layer 102 is positively correlated with the total area of ​​the step top surface and the step surface of the step structure 1011 .

[0134] In the embodiment of the present disclosure, the larger the radius of the arc is, the more the area of ​​the transparent conductive layer 102 is reduced. Therefore, the radius of the arc of the transparent conductive layer 102 is positively correlated with the top surface of the step structure 1011 and the total area of ​​the step surface, so that the larger the transparent conductive layer 102 is, the more edge areas can be transparent to ensure light extraction.

[0135] In the embodiment of the present disclosure, the total area of ​​the step top surface and the step surface of the step structure is less than or equal to 400 μm 2 The distance from the edge of the transparent conductive layer to the edge of the step top surface of the step structure is 3 to 5 μm, and the radius of the arc is 20 to 30 μm.

[0136] In the embodiment of the present disclosure, the total area of ​​the step top surface and the step surface of the step structure is greater than 400 μm 2 And less than or equal to 600μm 2 The distance from the edge of the transparent conductive layer to the edge of the step top surface of the step structure is 4 to 6 μm, and the radius of the arc is 20 to 30 μm.

[0137] In the embodiment of the present disclosure, the total area of ​​the step top surface and the step surface of the step structure is greater than 600 μm2 And less than or equal to 800μm 2 The distance from the edge of the transparent conductive layer to the edge of the step top surface of the step structure is 5 to 7 μm, and the radius of the arc is 20 to 40 μm.

[0138] In the embodiment of the present disclosure, the total area of ​​the step top surface and the step surface of the step structure is greater than 800 μm 2 And less than or equal to 1000μm 2 The distance from the edge of the transparent conductive layer to the edge of the step top surface of the step structure is 7 to 9 μm, and the radius of the arc is 20 to 40 μm.

[0139] In the embodiment of the present disclosure, the total area of ​​the step top surface and the step surface of the step structure is greater than 1000 μm 2 In the above, the distance from the edge of the transparent conductive layer to the edge of the step top surface of the step structure is 9-11 μm, and the radius of the arc is 30-50 μm.

[0140] S25, manufacturing a first electrode and a second electrode, wherein the first electrode is located on a step surface of the step structure, and the second electrode is located on the transparent conductive layer.

[0141] In the embodiment of the present disclosure, the first electrode and the second electrode may be AuGe / Au electrodes or AuBe / Au electrodes.

[0142] Exemplarily, the first electrode is an AuBe / Au electrode, and the second electrode is an AuGe / Au electrode.

[0143] S26. Making a passivation layer.

[0144] The passivation layer covers the epitaxial structure, the transparent conductive layer, the first electrode and the second electrode.

[0145] In the embodiment of the present disclosure, the passivation layer may be a SiO2 passivation layer.

[0146] The above description is only an optional embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. A light emitting diode, characterized in that: The light emitting diode comprises: an epitaxial structure (101), a transparent conductive layer (102), a first electrode (103) and a second electrode (104); The epitaxial structure (101) is provided with a step structure (1011), the step structure (1011) comprises a step bottom surface and a step top surface, the first electrode (103) is located on the step bottom surface of the step structure (1011), the transparent conductive layer (102) is located on the step top surface of the step structure (1011), and the second electrode (104) is located on the transparent conductive layer (102); The distance from the edge of the transparent conductive layer (102) to the edge of the step top surface of the step structure (1011) is greater than 0 and less than a first threshold value, and the first threshold value is positively correlated with the total area of ​​the step top surface and the step bottom surface of the step structure (1011).

2. The light emitting diode according to claim 1, characterized in that: The first threshold is no greater than 1.5% of the total area of ​​the step top surface and the step bottom surface of the step structure (1011).

3. The light emitting diode according to claim 2, characterized in that: The total area of ​​the step top surface and the step bottom surface of the step structure (1011) is less than or equal to 400 μm 2 , the distance from the edge of the transparent conductive layer (102) to the edge of the top surface of the step of the step structure (1011) is 3 to 5 μm; The total area of ​​the step top surface and the step bottom surface of the step structure (1011) is greater than 400 μm 2 And less than or equal to 600μm 2 , the distance from the edge of the transparent conductive layer (102) to the edge of the step top surface of the step structure (1011) is 4 to 6 μm; The total area of ​​the step top surface and the step bottom surface of the step structure (1011) is greater than 600 μm 2 And less than or equal to 800μm 2 , the distance from the edge of the transparent conductive layer (102) to the edge of the top surface of the step of the step structure (1011) is 5 to 7 μm; The total area of ​​the step top surface and the step bottom surface of the step structure (1011) is greater than 800 μm 2 And less than or equal to 1000μm 2 , the distance from the edge of the transparent conductive layer (102) to the edge of the top surface of the step of the step structure (1011) is 7 to 9 μm; The total area of ​​the step top surface and the step bottom surface of the step structure (1011) is greater than 1000 μm 2 The distance from the edge of the transparent conductive layer (102) to the edge of the top surface of the step of the step structure (1011) is 9 to 11 μm.

4. The light emitting diode according to any one of claims 1 to 3, characterized in that: The four corners of the transparent conductive layer (102) are arc-shaped.

5. The light emitting diode according to claim 4, characterized in that: The radius of the arc is positively correlated with the total area of ​​the step top surface and the step bottom surface of the step structure (1011).

6. The light emitting diode according to claim 5, characterized in that: The total area of ​​the step top surface and the step bottom surface of the step structure (1011) is less than or equal to 400 μm 2 , the radius of the arc is 20 to 30 μm; The total area of ​​the step top surface and the step bottom surface of the step structure (1011) is greater than 400 μm 2 And less than or equal to 600μm 2 , the radius of the arc is 20 to 30 μm; The total area of ​​the step top surface and the step bottom surface of the step structure (1011) is greater than 600 and less than or equal to 800 μm 2 , the radius of the arc is 20 to 40 μm; The total area of ​​the step top surface and the step bottom surface of the step structure (1011) is greater than 800 and less than or equal to 1000 μm 2 , the radius of the arc is 20 to 40 μm; The total area of ​​the step top surface and the step bottom surface of the step structure (1011) is greater than 1000 μm 2 , the radius of the arc is 30 to 50 μm.

7. A method for preparing a light emitting diode, characterized in that: The method comprises: Manufacturing an epitaxial structure, wherein the epitaxial structure is provided with a step structure, wherein the step structure comprises a step bottom surface and a step top surface; Manufacturing a transparent conductive layer, wherein the transparent conductive layer is located on the top surface of the step of the step structure, and the distance from the edge of the transparent conductive layer to the edge of the top surface of the step of the step structure is greater than 0 and less than a first threshold value, and the first threshold value is positively correlated with the total area of ​​the top surface and the bottom surface of the step of the step structure; A first electrode and a second electrode are manufactured, wherein the first electrode is located on the bottom surface of the step structure, and the second electrode is located on the transparent conductive layer.

8. The method for preparing a light emitting diode according to claim 7, characterized in that: The manufacturing of the transparent conductive layer comprises: Sputtering a layer of ITO film; forming a mask pattern on the ITO film; Under the shielding of the mask pattern, the ITO film is patterned to obtain the transparent conductive layer.

9. The method for preparing a light emitting diode according to claim 7 or 8, characterized in that: The first threshold is no greater than 1.5% of the total area of ​​the step top surface and the step bottom surface of the step structure.

10. The method for preparing a light emitting diode according to claim 7 or 8, characterized in that: The four corners of the transparent conductive layer are arc-shaped.

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