A light-emitting diode

Abstract

The present invention discloses a light-emitting diode, which includes: a substrate, a first semiconductor layer arranged on the surface of the substrate, a protrusion arranged on the surface of the first semiconductor layer, and a first reflective structure, wherein the surface of the first semiconductor layer includes a first conductive area and a second conductive area; the protrusion is arranged in the first conductive area of the first semiconductor layer, and the protrusion includes an active layer and a second semiconductor layer in sequence on the surface of the first semiconductor layer; the first reflective structure is arranged in each protrusion and penetrates the second semiconductor layer, the active layer and at least a portion of the first semiconductor layer, and the material of the first semiconductor layer includes Al x Ga 1‑x N, where X is between 0 and 1, and the wavelength of the light radiated by the light emitting diode is between 200 and 320 nm. As described above, the present invention can effectively shorten the propagation path of light within the epitaxial layer, reduce the absorption of light by the epitaxial layer, especially the first semiconductor layer, and improve the light extraction efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor devices, and in particular to a light emitting diode. Background Art

[0002] Ultraviolet (UV) light-emitting diodes (LEDs), which emit light with wavelengths between 100nm and 365nm, have significant applications in areas such as stationary lighting, sterilization, medical treatment, biochemical testing, and secure communications. Compared to UV light sources like mercury, deep UV LEDs based on aluminum gallium nitride (AlGaN) offer advantages such as robustness, energy efficiency, long lifespan, and mercury-free environmental protection. These diodes are gradually penetrating traditional applications such as mercury lamps.

[0003] Currently, deep ultraviolet (DUV) LEDs primarily use AlInGaN (aluminum gallium indium oxide) as the primary growth material for their epitaxial layers. Due to the high Al content of AlInGaN in the DUV LED epilayer, the light output is primarily in the transverse magnetic (TM) polarization mode, with the emission primarily propagating laterally within the epilayer. However, the materials in the epilayer absorb UV light, preventing it from being effectively emitted from the epilayer, thus impacting the LED's light extraction efficiency. Summary of the Invention

[0004] In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide a light emitting diode that can effectively reduce the absorption of light by the epitaxial layer and improve the luminous efficiency.

[0005] In order to achieve the above-mentioned and other related objects, the present invention provides a light emitting diode, comprising:

[0006] substrate;

[0007] A first semiconductor layer is provided on the surface of the substrate, wherein the surface of the first semiconductor layer includes a first conductive region and a second conductive region, and the material of the first semiconductor layer includes AlxGa1-xN, where X is a value between 0 and 1;

[0008] The protrusion is provided in the first conductive region of the first semiconductor layer, and the protrusion includes an active layer and a second semiconductor layer in sequence on the surface of the first semiconductor layer;

[0009] Wherein, the wavelength of the radiated light of the light emitting diode is between 200 and 320 nm;

[0010] The first reflective structure is arranged in each protrusion and penetrates the second semiconductor layer, the active layer and at least a portion of the first semiconductor layer.

[0011] Optionally, the value of X in the material of the first semiconductor layer is between 0.5 and 0.8.

[0012] Optionally, the protrusion extends in a direction parallel to the substrate and forms a plurality of spaced apart extensions. On each extension, there are a plurality of first reflective structures, and the plurality of first reflective structures are arranged in sequence along the extension direction of the extension.

[0013] Optionally, on each extension portion, the intervals between adjacent first reflective structures are equal.

[0014] Optionally, a distance between adjacent first reflective structures is less than 110 μm.

[0015] Optionally, the area of the vertical projection of all the first reflective structures on the substrate surface occupies more than 30% of the area of the vertical projection of the source layer on the substrate surface.

[0016] Optionally, the area of the vertical projection of all the first reflective structures on the substrate surface occupies 40% to 60% of the area of the vertical projection of the source layer on the substrate surface.

[0017] Optionally, a reflective hole is provided in the extension portion, the reflective hole passes through the second semiconductor layer, the active layer and at least a portion of the first semiconductor layer, the first reflective structure is formed as a reflective column, and the reflective column is filled in the reflective hole.

[0018] Optionally, a reflective hole is provided in the extension portion, the reflective hole passes through the second semiconductor layer, the active layer and at least a portion of the first semiconductor layer, the first reflective structure is formed as a reflective layer, and the reflective layer is formed on the surface of the reflective hole.

[0019] Optionally, the reflective layer is formed as a metal reflective layer or a Bragg reflective layer, and the reflective column is formed as a metal reflective column.

[0020] Optionally, the diameter of the reflective hole is between 3 μm and 10 μm.

[0021] Optionally, an angle between a sidewall of the reflective column or reflective layer disposed in the reflective hole and a plane where the substrate is located is between 20° and 60°.

[0022] Optionally, an insulating layer is provided on the inner wall of the reflective hole, and the reflective layer or the reflective column is formed on the insulating layer on the inner wall of the reflective hole.

[0023] Optionally, the light emitting diode radiates ultraviolet light, and the wavelength of the light radiated by the light emitting diode is between 200 nm and 285 nm.

[0024] Optionally, it also includes:

[0025] The second reflective structure covers the surface of the second semiconductor layer in the first conductive region.

[0026] Optionally, the second reflective structure is formed as a second electrode or a second electrode pad, and the second electrode or the second electrode pad is electrically connected to the second semiconductor layer.

[0027] Optionally, it also includes:

[0028] The first electrode is arranged on the surface of the first semiconductor layer in the second conductive region and forms an electrical connection with the first semiconductor layer. The area of the second conductive region accounts for more than 20% of the area of the entire surface of the first semiconductor layer, and the area of the second electrode in the second conductive region accounts for more than 80%.

[0029] Optionally, along the extension direction of the vertical extension portion, at least 70% of the extension portions have a width less than 110 μm.

[0030] Optionally, the thickness of the substrate is between 200 μm and 400 μm, or between 400 μm and 1000 μm.

[0031] Compared with the prior art, the light emitting diode of the present invention has at least the following beneficial effects:

[0032] The surface of the first semiconductor layer of the light-emitting diode of the present invention includes a first conductive area and a second conductive area, wherein the surface of the first semiconductor layer in the first conductive area includes a protrusion composed of an active layer and a second semiconductor layer, and the protrusion and the first semiconductor layer constitute an epitaxial layer of the light-emitting diode, and the first reflective structure is arranged in each protrusion and penetrates the second semiconductor layer, the active layer and at least a portion of the first semiconductor layer, wherein the material of the first semiconductor layer is Al x Ga 1- x The wavelength of the light radiated by the light emitting diode is between 200 and 320 nm. The present invention provides a first reflective structure within the epitaxial layer, which can effectively reduce the light absorption of the epitaxial layer, especially the first semiconductor layer, shortening the light propagation path and improving the light extraction efficiency of the LED.

[0033] Furthermore, the protrusion extends along a first direction (X direction) parallel to the substrate and forms a plurality of spaced extensions. The spacing between the extensions can partially cut off the epitaxial layer along a second direction (Y direction) perpendicular to the first direction, thereby shortening the propagation path of light emitted by the epitaxial layer along the second direction. At the same time, a first reflective structure is provided in each extension. The first reflective structure passes through the second semiconductor layer, the active layer and at least part of the first semiconductor layer, thereby shortening the propagation path of light in the epitaxial layer along the first direction, further reducing the amount of light absorbed by the epitaxial layer, and improving the light extraction efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a schematic cross-sectional structural diagram of a light emitting diode according to an embodiment of the present invention;

[0035] Figure 2 is a schematic cross-sectional structural diagram of a light emitting diode according to an embodiment of the present invention;

[0036] Figure 3 For the present invention Figure 1 or a schematic structural diagram of a projection of a partial structure of the light-emitting diode in 2 on a substrate surface;

[0037] Figure 4 Schematic diagram of the structure of a projection of a part of the structure of a light emitting diode on the surface of a substrate in one embodiment of the present invention;

[0038] Figure 5 is a schematic diagram of the cross-sectional structure of a light emitting diode in one embodiment of the present invention;

[0039] Figure 6 is a schematic diagram of the cross-sectional structure of a light emitting diode in one embodiment of the present invention;

[0040] Figure 7 is a schematic diagram of the cross-sectional structure of a light emitting diode in one embodiment of the present invention;

[0041] Figure 8 FIG. 4 is a flow chart of a method for preparing a light emitting diode according to an embodiment of the present invention.

[0042] List of reference numerals:

[0043] 100 substrate

[0044] 200 epitaxial layer

[0045] 210 first conductive area

[0046] 2100 protrusion

[0047] 2101 Extension

[0048] 211 first semiconductor layer

[0049] 212 active layer

[0050] 213 Second semiconductor layer

[0051] 220 second conductive area

[0052] 300 reflective hole

[0053] 400 insulation layer

[0054] 501 First Reflection Structure

[0055] 502 Second reflection structure

[0056] 601 first electrode contact layer

[0057] 602 second electrode contact layer

[0058] 701 first electrode

[0059] 702 second electrode

[0060] 801 first electrode pad

[0061] 802 second electrode pad DETAILED DESCRIPTION

[0062] The following specific embodiments illustrate the embodiments of the present invention. Those skilled in the art will readily appreciate the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different perspectives and applications without departing from the spirit of the present application. It should be noted that the following embodiments and features of the embodiments may be combined with each other unless they conflict.

[0063] It should be noted that the diagrams provided in the embodiments of the present invention are only schematic illustrations of the basic concept of the present invention. Although the diagrams only show components related to the present invention and are not drawn according to the number, shape, and size of components in actual implementation, the form, quantity, and proportion of each component in actual implementation can be changed at will, and the component layout form may also be more complex. The structures, proportions, sizes, etc. illustrated in the drawings of the specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the conditions for the implementation of this application. Therefore, they have no technical significance. Any structural modification, change in proportional relationship, or adjustment of size should still fall within the scope of the technical content disclosed in this application without affecting the efficacy and purpose of the present invention.

[0064] This embodiment provides a light-emitting diode, which includes a substrate, a first semiconductor layer disposed on a surface of the substrate, a protrusion disposed on a surface of the first semiconductor layer, and a first reflective structure, wherein the surface of the first semiconductor layer includes a first conductive region and a second conductive region; the protrusion is disposed in the first conductive region of the first semiconductor layer, and the surface of the first semiconductor layer includes an active layer and a second semiconductor layer in sequence; the first reflective structure is disposed in each protrusion and penetrates the second semiconductor layer, the active layer, and at least a portion of the first semiconductor layer; the material of the first semiconductor layer includes Al x Ga 1- x N, wherein X is between 0 and 1, and the wavelength of the radiated light of the light emitting diode is between 200 nm and 320 nm.

[0065] In one embodiment, referring to Figure 1 、 2In steps 5-7, the substrate 100 may be a sapphire substrate, a Si substrate, a SiC substrate, or a GaN substrate. In this embodiment, the substrate is a light-transmitting material, such as sapphire. The thickness of the sapphire substrate is between 200 μm and 400 μm, or between 400 μm and 1000 μm.

[0066] The epitaxial layer 200 is disposed on the surface of the substrate 100. The epitaxial layer 200 includes a first semiconductor layer 211, an active layer 212, and a second semiconductor layer 213 in the thickness direction of the substrate 100. Figure 1 、 2 or 5-7, refer to Figure 3 The surface of the first semiconductor layer 211 is formed with a first conductive region 210 and a second conductive region 220. The surface of the first semiconductor layer 211 in the first conductive region 210 includes a protrusion 2100 composed of an active layer 212 and a second semiconductor layer 213. The protrusion 2100 and the first semiconductor layer 211 form an epitaxial layer 200. In this embodiment, the first semiconductor layer 211 is an N-type semiconductor layer. The material of the first semiconductor layer 211 includes Al x Ga 1-x N, where X is between 0 and 1; optionally, the value of X in the material of the first semiconductor layer is between 0.5 and 0.8, the material of the second semiconductor layer 213 is P-GaN, the active layer 212 is a periodic structure composed of AlGaN quantum wells and AlGaN quantum barriers, and the epitaxial layer 200 is capable of radiating ultraviolet light, and the wavelength of the radiated light is less than 285 nm, preferably between 200 nm and 285 nm, for example, 280 nm, 265 nm or 220 nm.

[0067] Optionally, the light emitting diode includes a first electrode 701 and a second electrode 702. The first electrode 701 is formed on the surface of the first semiconductor layer 211 exposed in the second conductive region 220 and is electrically connected to the first semiconductor layer 211. The second electrode 702 is formed on the surface of the second semiconductor layer 213 and is electrically connected to the second semiconductor layer 213. Optionally, a first electrode contact layer 601 is provided between the first electrode 701 and the first semiconductor layer 211, and a second electrode contact layer 602 is provided between the second electrode 702 and the second semiconductor layer 213. In this embodiment, referring to Figure 1 、 2In embodiments 5-7, a first electrode contact layer 601 is formed on the surface of the first semiconductor layer 211 exposed in the second conductive region 220, and a first electrode 701 is formed above and covers the first electrode contact layer 601. Optionally, the first electrode contact layer 601 or the second electrode contact layer 602 is formed of a mixed alloy of multiple metals, such as an alloy of Ti, Au, Al, Ni, Cr, or Pt. The material of the first electrode 701 is a single metal layer. Optionally, the material of the first electrode 701 or the second electrode 702 is one of Ti, Au, Al, Ni, Cr, or Pt.

[0068] In one embodiment, referring to Figure 1 、 2 or 5-7, refer to Figure 3 The area of the first semiconductor layer 211 in the second conductive region 220 accounts for more than 20% of the area of the entire first semiconductor layer 211. The second electrode 702 is formed on the surface of the exposed first semiconductor layer 211 and accounts for more than 80% of the area of the exposed first semiconductor layer 211. Therefore, since the contact area between the second electrode 702 and the exposed first semiconductor layer 211 is large, it is more conducive to current expansion and avoids the adverse effects caused by current congestion.

[0069] In one embodiment, an insulating layer 400 is further provided over the electrode structures of the first conductive region 210 and the second conductive region 220 to protect the surface of the light emitting diode.

[0070] The first reflective structure 501 is disposed within the protrusion 2100 and extends through the second semiconductor layer 213, the active layer 212, and at least a portion of the first semiconductor layer 211. Optionally, the first reflective structure 501 may be made of a metallic reflective material, such as rhodium, aluminum, or silver. Optionally, the first reflective structure 501 may be formed as a DBR reflective layer, i.e., a Bragg reflector. The DBR reflective layer is formed by repeatedly overlapping dielectric layers with different refractive indices. For example, the dielectric layers may include TiO2, SiO2, HfO2, ZrO2, Nb2O5, MgF2, or the like. In this embodiment, the first reflective structure 501 is made of metallic aluminum.

[0071] In one embodiment, referring to Figure 3The protrusion 2100 extends in a direction parallel to the substrate 100 and forms a plurality of spaced extensions 2101, and the plurality of extensions 2101 are an integral structure. On each extension 2101, there are a plurality of first reflective structures 501, and the plurality of first reflective structures 501 are arranged in sequence along the extension direction of the extension 2101. Optionally, the spacing between adjacent first reflective structures 501 is equal to ensure uniformity of light output. Optionally, the spacing D1 between adjacent first reflective structures 501 is less than 110 μm, for example, between 20 μm and 110 μm. Optionally, along the extension direction perpendicular to the extension 2101, the width D2 of at least 70% of the extensions 2101 is less than 110 μm. The spacing between the extensions 2101 can cut off the epitaxial layer 200 along the Y direction (the X direction is perpendicular to the Y direction), thereby shortening the propagation path of the light emitted from the epitaxial layer 200 along the Y direction. A first reflective structure 501 is provided in each extension portion 2101 , which can shorten the light propagation path of the epitaxial layer along the X direction, further reduce the amount of light absorbed by the epitaxial layer, and improve the light extraction efficiency.

[0072] In one embodiment, referring to Figure 1 、 2 Or 7, a reflective hole 300 is provided in the extension portion 2101, and the reflective hole 300 passes through the second semiconductor layer 213, the active layer 212 and at least a portion of the first semiconductor layer 211. The first reflective structure 501 is formed as a reflective column, which is filled in the reflective hole 300. Optionally, the diameter of the reflective hole is between 3μm and 10μm. Optionally, the angle between the side wall of the reflective hole and the plane where the substrate is located is between 20° and 60°, so that the angle α between the side wall of the reflective column or reflective layer formed in the reflective hole and the plane where the substrate is located is also between 20° and 60°, so as to ensure that as much light emitted by the epitaxial layer as possible is reflected to the light-emitting surface, thereby improving the luminous efficiency. When the material of the first reflective structure 501 is a metal reflective material, an insulating layer 400 is also coated in the reflective hole 300, and the insulating layer 400 is used to form an electrical insulation between the epitaxial layer 200 and the first reflective structure 501. In an optional embodiment, refer to Figure 5 Or 6, the first reflective structure 501 is formed as a reflective layer, which is formed on the inner wall of the reflective hole 300. Similarly, when the material of the first reflective structure 501 is a metal reflective material, an insulating layer 400 is further provided in the reflective hole 300, and the reflective layer is formed on the surface of the insulating layer 400.

[0073] In one embodiment of the present invention, referring to Figure 1 、 2Or 5-7, the light-emitting diode further includes a second reflective structure 502, which covers the surface of the second semiconductor layer 213 and is used to reflect the light emitted by the second semiconductor layer 213 to the light-emitting surface in the direction of the first semiconductor layer 211 to increase the amount of light emitted. Optionally, the second reflective structure 502 is formed as an integral structure with at least one first reflective structure 501, or it can be separated from the first reflective structure 502 by an insulating layer 400. Optionally, the material of the second reflective structure 502 is a metal reflective material. In this case, the second reflective structure 502 can be used as an electrode or an electrode pad. In one embodiment, as Figure 1 As shown in FIG5 , the second reflective structure 502 and at least two first reflective structures 501 form an integral structure, and the second reflective structure 502 is used as the second electrode 702. In one embodiment, as shown in FIG5 , the second reflective structure 502 and the at least two first reflective structures 501 form an integral structure. Figure 2 As shown in FIG. 7 , the second reflective structure 502 and at least two first reflective structures 501 form an integral structure, and in this embodiment,

[0074] The second reflective structure 502 is used as the second electrode pad 702. In one embodiment, Figure 6 As shown, the second reflective structure 502 is separated from the first reflective structure 501 by the insulating layer 400 and serves as the second electrode 702 .

[0075] The proportion of the first reflective structure 501 provided in the first conductive region 210 in the epitaxial layer 200, especially the proportion of the active layer 212, will seriously affect the light output of the LED. In this embodiment, the area of the vertical projection of the first reflective structure 501 on the surface of the substrate 100 occupies more than 30% of the area of the vertical projection of the active layer 212 on the surface of the substrate 100. It should be noted that the proportion of the area of the vertical projection of the first reflective structure 501 on the surface of the substrate 100 to the area of the vertical projection of the active layer 212 on the surface of the substrate 100 needs to be less than 60% to avoid the voltage increase problem caused by the small area of the active area. Preferably, the area of the vertical projection of the first reflective structure 501 on the surface of the substrate 100 occupies 40% to 60% of the area of the vertical projection of the active layer 212 on the surface of the substrate 100, which can effectively improve the light output of the LED. Optionally, the vertical projection area of each first reflective structure 501 on the surface of the substrate 100 occupies less than 10% of the vertical projection area of the active layer 212 on the surface of the substrate 100, and optionally, between 2% and 8%. Thus, this embodiment can effectively improve light extraction efficiency by controlling the proportion of the first reflective structure within the active layer, reducing the impact of the first reflective structure occupying a certain amount of light-emitting area on the light output of the LED.

[0076] In another embodiment of the present invention, a method for preparing a light emitting diode is provided. Figure 8 , the steps include:

[0077] S101: providing a substrate;

[0078] Reference Figure 1 、 2 In steps 5 to 7, a substrate 100 is provided. In this embodiment, the substrate 100 is a sapphire substrate 100 .

[0079] S102: forming an epitaxial layer consisting of a first semiconductor layer, an active layer, and a second semiconductor layer in sequence on a surface of the substrate, etching and exposing a portion of the first semiconductor layer in a direction from the second semiconductor layer to the first semiconductor layer, the exposed first semiconductor layer forming a second conductive region of the first semiconductor layer, and the unexposed first semiconductor layer forming a first conductive region of the first semiconductor layer; forming a protrusion consisting of the active layer and the second semiconductor layer on a surface of the first semiconductor layer within the first conductive region, the protrusion extending in a direction parallel to the substrate and forming a plurality of spaced-apart extensions;

[0080] In one embodiment, referring to Figure 1 、 2 or 5-7, refer to Figure 3 A first semiconductor layer 211, an active layer 212, and a second semiconductor layer 213 are sequentially formed on the surface of the substrate 100 by chemical vapor deposition. A portion of the first semiconductor layer 211 is etched and exposed along the direction from the second semiconductor layer 213 to the first semiconductor layer 211 to form a second conductive region 220. Optionally, the area of the exposed first semiconductor layer 211 is controlled to account for more than 20% of the area of the entire first semiconductor layer 211. The unexposed first semiconductor layer 211 forms a first conductive region 210. The surface of the first semiconductor layer 211 in the first conductive region 210 includes a protrusion 2100 composed of the active layer 212 and the second semiconductor layer 213. The protrusion 2100 extends in a direction parallel to the substrate 100 and forms a plurality of spaced extensions 2101. In this embodiment, as shown in FIG. Figure 3 or Figure 4 , the first conductive region 210 or the protrusion 2100 is in an “E” shape.

[0081] S103: forming a first reflective structure in the extension portion, wherein the first reflective structure penetrates the second semiconductor layer, the active layer, and at least a portion of the first semiconductor layer.

[0082] In one embodiment, referring to Figure 1 、 56, a second electrode contact layer 602 is deposited on the surface of the second semiconductor layer 213, and the second semiconductor layer 213, the active layer 212, and the first semiconductor layer 211 are sequentially etched on the surface of the second electrode contact layer 602 to form a reflective hole 300, so that the reflective hole 300 sequentially passes through the second electrode contact layer 602, the second semiconductor layer 213, the active layer 212, and at least a portion of the first semiconductor layer 211. An insulating material is deposited on the sidewalls of the reflective hole 300 to form an insulating layer 400, and a metal reflective material is deposited on the surface of the insulating layer 400 to form a reflective layer or a reflective column. A second electrode 702 is formed above the second electrode contact layer 602. When the material of the second electrode 702 is a metal reflective material, the second electrode 702 can serve as a second reflective structure 502 to reflect light emitted from the epitaxial layer 200. In this embodiment, referring to Figure 1 、 5 Alternatively, in step 6, a metal material is deposited over the second electrode contact layer 602 to form a second electrode 702. The at least two first reflective structures 501 are integrated with the second electrode 702. The first electrode contact layer 601 is formed on the surface of the exposed first semiconductor layer 211, and the first electrode 701 is formed on the surface of the first electrode contact layer 601. Optionally, the first electrode 701 occupies more than 80% of the area of the exposed first semiconductor layer 211.

[0083] Optionally, an insulating layer 400 is formed over the structure formed above, the insulating layer 400 is etched to expose portions of the first electrode 701 and the second electrode 702 , and first electrode pads 801 and second electrode pads 802 are formed on the exposed first electrode 701 and second electrode 702 .

[0084] In one embodiment, referring to Figure 2 Or 7, a second electrode contact layer 602 and a second electrode 702 are sequentially deposited on the surface of the second semiconductor layer 213 in the second conductive region 220, and the second electrode contact layer 602, the second semiconductor layer 213, the active layer 212 and the first semiconductor layer 211 are sequentially etched on the surface of the second electrode 702 to form a reflective hole 300, which sequentially passes through the second electrode 702, the second electrode contact layer 602, the second semiconductor layer 213, the active layer 212 and at least a portion of the first semiconductor layer 211. An insulating layer 400 is formed on the inner wall of the reflective hole 300 and the surface of the second electrode 702, and the excess insulating layer 400 is etched away. A metal reflective material is deposited in the reflective hole 300 to form a first reflective structure 501. A metal material is deposited on the surface of the second electrode 702 to form a second electrode pad 802. In this embodiment, referring to Figure 2Or 7, the material of the second electrode pad 802 is a metal reflective material, such as Al or Ag, and the second electrode pad 802 can serve as the second reflective structure 502 to reflect light emitted from the epitaxial layer 200. Optionally, at least two first reflective structures 501 and the second electrode pad 802 form an integrated structure.

[0085] Alternatively, as Figure 3 As shown in FIG4 , on the surface of the protrusion 2100 in the first conductive region 210 , the first reflective structure 501 is arranged along the extension direction of the extension portion 2101 . Optionally, the number of the first reflective structures 501 arranged on each extension portion 2101 is at least 3, preferably 5.

[0086] In summary, the surface of the first semiconductor layer of the light-emitting diode of the present invention includes a first conductive region and a second conductive region, wherein the surface of the first semiconductor layer in the first conductive region includes a protrusion composed of an active layer and a second semiconductor layer, and the protrusion and the first semiconductor layer constitute an epitaxial layer of the light-emitting diode, and the first reflective structure is arranged in each protrusion and penetrates the second semiconductor layer, the active layer and at least the first semiconductor layer, wherein the material of the first semiconductor layer includes Al x Ga 1-x The wavelength of the light radiated by the light emitting diode is between 200 and 320 nm. The present invention provides a first reflective structure within the epitaxial layer, which can effectively reduce the light absorption of the epitaxial layer, especially the first semiconductor layer, shortening the light propagation path and improving the light extraction efficiency of the LED.

[0087] Furthermore, the protrusion extends along a first direction (X direction) parallel to the substrate and forms a plurality of spaced extensions. The spacing between the extensions can partially cut off the epitaxial layer along a second direction (Y direction) perpendicular to the first direction, thereby shortening the propagation path of light emitted by the epitaxial layer along the second direction. At the same time, a first reflective structure is provided in each extension. The first reflective structure passes through the second semiconductor layer, the active layer and at least part of the first semiconductor layer, thereby shortening the propagation path of light in the epitaxial layer along the first direction, further reducing the amount of light absorbed by the epitaxial layer, and improving the light extraction efficiency.

[0088] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A light emitting diode, characterized in that: include: substrate; The first semiconductor layer is provided on the surface of the substrate, and the surface of the first semiconductor layer includes a first conductive area and a second conductive area; the material of the first semiconductor layer includes Al x Ga 1-x N, where X ranges from 0 to 1; a protrusion disposed in the first conductive region of the first semiconductor layer, wherein the protrusion sequentially includes an active layer and a second semiconductor layer on a surface of the first semiconductor layer, and the protrusion extends in a direction parallel to the substrate to form a plurality of extensions spaced apart from each other; a first reflective structure disposed in each of the protruding portions and penetrating the second semiconductor layer, the active layer, and at least a portion of the first semiconductor layer; and a plurality of first reflective structures are disposed on each of the extending portions, and the plurality of first reflective structures are sequentially arranged along an extending direction of the extending portion; The wavelength of the radiated light of the light emitting diode is between 200 nm and 320 nm.

2. The light emitting diode according to claim 1, characterized in that The value of X in the material of the first semiconductor layer is between 0.5 and 0.

8.

3. The light emitting diode according to claim 1, characterized in that On each of the extending portions, the intervals between adjacent first reflective structures are equal.

4. The light emitting diode according to claim 3, characterized in that The distance between adjacent first reflective structures is less than 110 μm.

5. The light emitting diode according to claim 1, characterized in that The area of the vertical projection of all the first reflective structures on the surface of the substrate accounts for more than 30% of the area of the vertical projection of the active layer on the surface of the substrate.

6. The light emitting diode according to claim 1, characterized in that The area of the vertical projection of all the first reflective structures on the surface of the substrate accounts for 40% to 60% of the area of the vertical projection of the active layer on the surface of the substrate.

7. The light emitting diode according to claim 1, characterized in that A reflective hole is provided in the extension portion, and the reflective hole passes through the second semiconductor layer, the active layer and at least a portion of the first semiconductor layer. The first reflective structure is formed as a reflective column, and the reflective column is filled in the reflective hole.

8. The light emitting diode according to claim 1, characterized in that A reflective hole is provided in the extension portion, and the reflective hole passes through the second semiconductor layer, the active layer and at least a portion of the first semiconductor layer. The first reflective structure is formed as a reflective layer, and the reflective layer is formed on a surface of the reflective hole.

9. The light emitting diode according to claim 7 or 8, characterized in that: When the first reflective structure is a reflective layer, the reflective layer is formed as a metal reflective layer or a Bragg reflective layer; when the first reflective structure is a reflective column, the reflective column is formed as a metal reflective column.

10. The light emitting diode according to claim 7 or 8, characterized in that: The diameter of the reflective hole is between 3 μm and 10 μm.

11. The light emitting diode according to claim 7 or 8, characterized in that: An included angle between a sidewall of the first reflective structure disposed in the reflective hole and a plane where the substrate is located is between 20° and 60°.

12. The light emitting diode according to claim 7 or 8, characterized in that: An insulating layer is provided on the inner wall of the reflective hole, and the first reflective structure is formed on the insulating layer on the inner wall of the reflective hole.

13. The light emitting diode according to claim 1, characterized in that The light emitting diode radiates ultraviolet light, and the radiation wavelength of the light emitting diode is between 200 nm and 285 nm.

14. The light emitting diode according to claim 1, characterized in that Also includes: The second reflective structure covers the surface of the second semiconductor layer in the first conductive region.

15. The light emitting diode according to claim 14, characterized in that The second reflective structure is formed as a second electrode or a second electrode pad, and the second electrode or the second electrode pad is electrically connected to the second semiconductor layer.

16. The light emitting diode according to claim 1, characterized in that Also includes: The first electrode is arranged on the surface of the first semiconductor layer in the second conductive region and is electrically connected to the first semiconductor layer. The area of the second conductive region accounts for more than 20% of the area of the entire first semiconductor layer, and the area of the first electrode in the second conductive region accounts for more than 80%.

17. The light emitting diode according to claim 1, characterized in that Along an extending direction perpendicular to the extending portion, at least 70% of the extending portion has a width less than 110 μm.

18. The light emitting diode according to claim 1, characterized in that The thickness of the substrate is between 200 μm and 400 μm, or between 400 μm and 1000 μm.

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