Light emitting diode and light emitting panel

Abstract

The embodiment of the utility model provides a light-emitting diode and a light-emitting panel, and belongs to the technical field of semiconductors. The light-emitting diode comprises a light-emitting structure, a first insulating layer and a metal reflecting layer, wherein the light-emitting structure comprises a first semiconductor layer, a light-emitting layer and a second semiconductor layer which are stacked in sequence; the first insulating layer is located on the surface, away from the light-emitting layer, of the second semiconductor layer and provided with a plurality of through holes; the metal reflecting layer is located on the surface, away from the light-emitting structure, of the first insulating layer and electrically connected with the second semiconductor layer through a plurality of through holes, and the orthographic projection of the metal reflecting layer on the first semiconductor layer is located in the outer contour of the orthographic projection of the first insulating layer on the first semiconductor layer; the first semiconductor layer includes an orthographic projection of the second semiconductor layer on the first semiconductor layer. According to the embodiment of the invention, the luminous efficiency of the LED can be improved.

Description

Technical Field

[0001] The present disclosure relates to the field of semiconductor technology, and in particular to a light emitting diode and a light emitting panel. Background Art

[0002] Light emitting diodes (LEDs) have been widely used in various light source fields such as backlighting, lighting, landscaping, and display screens due to their small size, long service life, rich colors, and low energy consumption.

[0003] In related art, an LED includes a light-emitting structure, an insulating layer, and a metal reflective layer. The light-emitting structure includes a first semiconductor layer, a light-emitting layer, and a second semiconductor layer stacked in sequence. The insulating layer is located on the surface of the second semiconductor layer away from the light-emitting layer and has multiple through-holes. The metal reflective layer is located on the surface of the insulating layer away from the light-emitting structure and is electrically connected to the second semiconductor layer through multiple through-holes. The orthographic projection of the metal reflective layer on the first semiconductor layer is located within the outer contour of the orthographic projection of the insulating layer on the first semiconductor layer, and is also located within the orthographic projection of the second semiconductor layer on the first semiconductor layer. The light-emitting surface of the LED is the side where the first semiconductor layer is located.

[0004] However, the metal reflective layer has a small coverage area, and part of the light emitted by the light-emitting structure and directed toward the side where the second semiconductor layer is located may be emitted from the area not covered by the metal reflective layer, that is, from the side opposite to the light-emitting surface of the LED, thereby affecting the luminous efficiency of the LED. Utility Model Content

[0005] The embodiments of the present disclosure provide a light-emitting diode and a light-emitting panel, which can improve the luminous efficiency of the LED. The technical solution is as follows:

[0006] On the one hand, a light-emitting diode is provided, comprising a light-emitting structure, a first insulating layer and a metal reflective layer, wherein the light-emitting structure comprises a first semiconductor layer, a light-emitting layer, and a second semiconductor layer stacked in sequence; the first insulating layer is located on a surface of the second semiconductor layer away from the light-emitting layer, and the first insulating layer has a plurality of through holes; the metal reflective layer is located on a surface of the first insulating layer away from the light-emitting structure and is electrically connected to the second semiconductor layer through the plurality of through holes, the orthographic projection of the metal reflective layer on the first semiconductor layer being located within an outer contour of the orthographic projection of the first insulating layer on the first semiconductor layer, and containing the orthographic projection of the second semiconductor layer on the first semiconductor layer.

[0007] Optionally, the light emitting structure has a first sidewall, the first insulating layer has a first portion, the first portion is located on a surface of the first sidewall, and a portion of the metal reflective layer is located on a surface of the first portion away from the first sidewall.

[0008] Optionally, the light-emitting structure has a groove extending from the surface of the second semiconductor layer away from the light-emitting layer toward the first semiconductor layer, the sidewall of the groove is the first sidewall, and the angle between the surface of the metal reflective layer on the first part and the bottom surface of the groove is 30° to 60°.

[0009] Optionally, the orthographic projection of the light-emitting layer on the first semiconductor layer is located inside the orthographic projection of the metal reflective layer on the first semiconductor layer.

[0010] Optionally, the through hole is a tapered hole, and a large end of the tapered hole is away from a surface of the second semiconductor layer.

[0011] Optionally, the first insulating layer includes a current blocking layer and an insulating reflective layer stacked in sequence in a direction away from the light emitting structure.

[0012] Optionally, the light emitting diode further includes a protective layer, wherein the protective layer is located on a surface of the metal reflective layer away from the first insulating layer and on a side wall of the metal reflective layer.

[0013] Optionally, the protective layer includes an Al2O3 layer and a SiO2 layer stacked in sequence in a direction away from the metal reflective layer.

[0014] Optionally, the light-emitting diode further includes a substrate, a transparent conductive layer, a connecting electrode layer, a second insulating layer and a pad electrode layer, wherein the substrate is located on the surface of the light-emitting structure away from the first insulating layer; the transparent conductive layer is located between the second semiconductor layer and the first insulating layer, and the metal reflective layer is connected to the transparent conductive layer through the multiple through holes; the connecting electrode layer is located on the surface of the protective layer away from the substrate, and the connecting electrode layer includes a first connecting electrode and a second connecting electrode, the first connecting electrode passes through the first insulating layer and the protective layer and is connected to the first semiconductor layer, and the second connecting electrode passes through the protective layer and is connected to the metal reflective layer; the second insulating layer is located on the surface of the connecting electrode layer away from the light-emitting structure and the surface of the protective layer away from the light-emitting structure; the pad electrode layer includes a first pad electrode and a second pad electrode, the first pad electrode passes through the second insulating layer and is connected to the first connecting electrode, and the second pad electrode passes through the second insulating layer and is connected to the second connecting electrode.

[0015] On the other hand, a light-emitting panel is provided, comprising a light-emitting functional layer and a driving backplane, wherein the light-emitting functional layer is located on the surface of the driving backplane and is electrically connected to the driving backplane, and the light-emitting functional layer comprises a plurality of any of the aforementioned light-emitting diodes.

[0016] The technical solutions provided by the embodiments of the present disclosure have the following beneficial effects:

[0017] In the disclosed embodiments, the metal reflective layer is located on a surface of the first insulating layer away from the light-emitting structure and is electrically connected to the second semiconductor layer via multiple through-holes in the first insulating layer. The orthographic projection of the metal reflective layer on the first semiconductor layer is located within the outer contour of the orthographic projection of the first insulating layer on the first semiconductor layer and includes the orthographic projection of the second semiconductor layer on the first semiconductor layer. The metal reflective layer has a large coverage area, so it can reflect more light emitted by the light-emitting structure and directed toward the side where the second semiconductor layer is located back to the light-emitting structure, thereby allowing more light to be emitted from the light-emitting surface of the LED, thereby improving the luminous efficiency of the LED. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the following briefly introduces the drawings required for use in the description of the embodiments. 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 any creative work.

[0019] Figure 1 This is a schematic structural diagram of an LED provided by an embodiment of the present disclosure;

[0020] Figure 2 is a top view of an LED provided by an embodiment of the present disclosure;

[0021] Figure 3 This is a flow chart of a method for preparing an LED provided by an embodiment of the present disclosure;

[0022] Figure 4 This is a flow chart of another method for preparing an LED provided in an embodiment of the present disclosure.

[0023] Reference numerals:

[0024] x: first direction; y: second direction; 10: light-emitting structure; 101: first side wall; 11: first semiconductor layer; 12: light-emitting layer; 13: second semiconductor layer; 14: groove; 141: bottom surface; 20: first insulating layer; 201: first part; 21: through hole; 22: current blocking layer; 23: insulating reflective layer; 30: metal reflective layer; 40: protective layer; 50: transparent conductive layer; 60: substrate; 70: first connecting electrode; 701: first sub-electrode; 702: second sub-electrode; 71: second connecting electrode; 711: connecting portion; 712: strip portion; 72: anti-top-pin electrode; 80: second insulating layer; 81: first opening; 82: second opening; 90: first pad electrode; 91: second pad electrode. DETAILED DESCRIPTION

[0025] 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.

[0026] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning understood by persons of ordinary skill in the field to which the present disclosure belongs. The words “first”, “second”, “third” and similar terms used in the patent application specification and claims of the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as “one” or “a” do not indicate a quantity limitation, but rather indicate the existence of at least one. Words such as “include” and similar terms mean that the elements or objects appearing before “include” include the elements or objects listed after “include” and their equivalents, and do not exclude other elements or objects. Words such as “connect” and similar terms are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. “Up”, “down”, “left”, “right”, “top”, “bottom” and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0027] Figure 1 This is a schematic diagram of the structure of an LED provided by an embodiment of the present disclosure. Figure 1As shown, the LED includes a light-emitting structure 10, a first insulating layer 20, and a metal reflective layer 30. The light-emitting structure 10 includes a first semiconductor layer 11, a light-emitting layer 12, and a second semiconductor layer 13 stacked in sequence. The first insulating layer 20 is located on the surface of the second semiconductor layer 13 away from the light-emitting layer 12 and has a plurality of through-holes 21. The metal reflective layer 30 is located on the surface of the first insulating layer 20 away from the light-emitting structure 10 and is electrically connected to the second semiconductor layer 13 through the plurality of through-holes 21. The orthographic projection of the metal reflective layer 30 on the first semiconductor layer 11 is located within the outer contour of the orthographic projection of the first insulating layer 20 on the first semiconductor layer 11 and includes the orthographic projection of the second semiconductor layer 13 on the first semiconductor layer 11. Here, electrical connection includes both direct and indirect electrical connection. The orthographic projection of the metal reflective layer 30 on the first semiconductor layer 11 includes the orthographic projection of the second semiconductor layer 13 on the first semiconductor layer 11, that is, the orthographic projection of the second semiconductor layer 13 on the first semiconductor layer 11 is located within the orthographic projection of the metal reflective layer 30 on the first semiconductor layer 11.

[0028] Figure 1 The arrows in the figure indicate the propagation path of the light near the metal reflective layer 30. In the embodiment of the present disclosure, the coverage area of ​​the metal reflective layer 30 is large. Therefore, the metal reflective layer 30 can reflect more light emitted by the light-emitting structure 10 and directed toward the side where the second semiconductor layer 13 is located back to the light-emitting structure 10, thereby allowing more light to be emitted from the light-emitting surface of the LED, thereby improving the luminous efficiency of the LED.

[0029] In the embodiment of the present disclosure, the LED may be a flip-chip LED.

[0030] like Figure 1 As shown, the light-emitting structure 10 has a first sidewall 101, and the first insulating layer 20 has a first portion 201. The first portion 201 is located on the surface of the first sidewall 101, and a portion of the metal reflective layer 30 is located on the surface of the first portion 201 away from the first sidewall 101. In other words, the metal reflective layer 30 is partially disposed in the upper region of the first sidewall 101 of the light-emitting structure 10. This ensures that the metal reflective layer 30 effectively reflects light in the upper region of the first sidewall 101, thereby allowing more light emitted from the first sidewall 101 of the light-emitting structure 10 toward the metal reflective layer 30 to be reflected back to the light-emitting structure 10 and emitted from the light-emitting surface of the LED.

[0031] In other embodiments, the metal reflective layer 30 may also be located only on the first insulating layer 20 in the area above the second semiconductor layer 13, and electrically connected to the second semiconductor layer 13 through multiple through holes, but not arranged on the surface of the first portion 201 away from the first side wall 101, so as to ensure that the orthographic projection of the metal reflective layer 30 on the first semiconductor layer 11 includes the orthographic projection of the second semiconductor layer 13 on the first semiconductor layer 11.

[0032] Exemplarily, the thickness of the metal reflective layer 30 on the first portion 201 is uniform.

[0033] Figure 2 This is a top view of an LED provided by an embodiment of the present disclosure. Figure 2 The metal reflective layer and the plurality of through holes in the first insulating layer are not shown. Figure 1 Can be Figure 2 Schematic diagram of the cross-section structure at the AA line, see Figure 1 and Figure 2 The light-emitting structure 10 has a plurality of grooves 14 arranged in an array, extending from the surface of the second semiconductor layer 13 away from the light-emitting layer 12 toward the first semiconductor layer 11. The sidewalls of the grooves 14 are first sidewalls 101. The angle α between the surface of the metal reflective layer 30 on the first portion 201 and the bottom surface 141 of the grooves 14 is 30° to 60°. If α is too small, the light-emitting area of ​​the LED will be affected; if α is too large, the metal reflective layer 30 may break and fall off on the first portion 201, causing a short circuit failure and affecting the reliability of the LED. When α is within this range, the surface angle of the metal reflective layer 30 on the first portion 201 can be ensured to be more gentle, which ensures a more reliable connection between the metal reflective layer 30 and the first portion 201 without affecting the light-emitting area of ​​the LED, thereby reducing the probability of the metal reflective layer 30 breaking and falling off, causing a short circuit failure, and improving the reliability of the LED.

[0034] Optionally, the orthographic projection of the light-emitting layer 12 on the first semiconductor layer 11 is located inside the orthographic projection of the metal reflective layer 30 on the first semiconductor layer 11. Since the principle of LED light emission is the radiative recombination of holes and electrons in the light-emitting layer 12 to generate photons, this can further ensure that the metal reflective layer 30 on the side where the second semiconductor layer 13 is located more effectively covers the possible light emission area, thereby further improving the luminous efficiency of the LED.

[0035] Optionally, the metal reflective layer 30 includes an Ag layer. Due to its high reflectivity, the Ag layer can effectively reflect the light emitted by the light-emitting layer 12 back toward the light-emitting structure 10, thereby effectively improving the luminous efficiency of the LED. In addition, Ag has good conductivity and low resistance, which is conducive to carrier injection.

[0036] Illustratively, the metal reflective layer 30 may include an Ag layer, a Ni layer, a Ti layer, and a TiW layer sequentially stacked in a direction away from the first insulating layer 20 .

[0037] Optionally, the LED further includes a protective layer 40, which is located on the surface of the metal reflective layer 30 away from the first insulating layer 20 and on the sidewalls of the metal reflective layer 30. Part of the protective layer 40 is located on the surface of the first insulating layer 20 and connected to the first insulating layer 20. Ag in the metal reflective layer 30 is highly active but relatively unstable, and Ag is prone to migration, leading to short circuit failure within the LED. The protective layer 40 protects the metal reflective layer 30, thereby improving the reliability of the LED.

[0038] Optionally, the protective layer 40 includes an Al2O3 layer and a SiO2 layer stacked sequentially in a direction away from the metal reflective layer 30. The Al2O3 layer has good density and can effectively reduce the probability of migration of the metal reflective layer 30. The SiO2 layer is relatively low in cost. Therefore, the protective layer 40 can reduce production costs while effectively improving the reliability of the LED.

[0039] In other embodiments, the protective layer 40 may also be an Al 2 O 3 layer, which is not limited in the present disclosure.

[0040] Optionally, the LED further includes a transparent conductive layer 50, which is located between the second semiconductor layer 13 and the first insulating layer 20. The metal reflective layer 30 is connected to the transparent conductive layer 50 via a plurality of through-holes 21. The transparent conductive layer 50 may also be referred to as a current spreading layer. The transparent conductive layer 50 can laterally spread the current to various regions of the second semiconductor layer 13, thereby ensuring a high internal quantum efficiency of the LED.

[0041] Optionally, the transparent conductive layer 50 may be an indium tin oxide (ITO) layer. ITO has good transmittance and low resistivity, thus ensuring the light output effect of the LED, and also facilitating carrier conduction and improving carrier injection efficiency.

[0042] Optionally, the through hole 21 is a tapered hole, with the large end of the tapered hole away from the surface of the second semiconductor layer 13. Since the metal reflective layer 30 is connected to the transparent conductive layer 50 through multiple tapered holes, the metal reflective layer 30 can be reliably connected to the sidewalls of the tapered holes and to the transparent conductive layer 50 at the small end of the tapered hole. This can reduce the probability of the metal reflective layer 30 and the first insulating layer 30 falling off, thereby improving the reliability of the LED.

[0043] Optionally, the first insulating layer 20 includes a current blocking layer 22 and an insulating reflective layer 23 stacked sequentially in a direction away from the light-emitting structure 10. Thus, the current blocking layer 22 can cooperate with the metal reflective layer 30 to prevent current from concentrating in a large area directly below the metal reflective layer 30, thereby improving the current spreading capability and allowing the current to better spread laterally to various areas of the second semiconductor layer 13. The insulating reflective layer 23 can also increase the reflectivity of the first insulating layer 20 to light, thereby improving the luminous efficiency of the LED.

[0044] Optionally, the current blocking layer 22 may be at least one of a SiO 2 layer, an Al 2 O 3 layer, a SiN layer, or a SiON layer. For example, the current blocking layer 22 may be a SiO 2 layer.

[0045] Optionally, the insulating reflective layer 23 may be a distributed Bragg reflector (DBR) layer. The DBR layer has a high reflectivity for light, which can reduce the absorption of light by the first insulating layer 20. The DBR layer and the metal reflective layer 30 can form an omni-directional reflector (ODR) structure. The ODR structure has a better light reflection effect, which is conducive to improving the luminous efficiency of the LED.

[0046] Exemplarily, the DBR layer includes a plurality of SiO2 layers and a plurality of Ti3O5 layers that are periodically alternately stacked. The number of periods of the DBR layer may be 20 to 50. For example, the DBR layer may include 30 SiO2 layers and 30 Ti3O5 layers that are periodically alternately stacked.

[0047] Optionally, the LED further includes a substrate 60, which is located on a surface of the light emitting structure 10 away from the first insulating layer 20. The substrate 60 can provide support for the light emitting structure 10, thereby ensuring better reliability of the LED.

[0048] Optionally, substrate 60 may be a sapphire substrate. Sapphire substrates are transparent substrates with good light transmittance, high mechanical strength, and easy to handle and clean. In other embodiments, substrate 60 may also be a Si substrate or a SiC substrate, which is not limited in this disclosure.

[0049] Optionally, the LED may further include a buffer layer, which is located between the substrate 60 and the light emitting structure 10 .

[0050] Exemplarily, the buffer layer may be a GaN buffer layer.

[0051] Optionally, the first semiconductor layer 11 may be an N-type GaN layer, and the second semiconductor layer 13 may be a P-type GaN layer.

[0052] Exemplarily, the first semiconductor layer 11 is a Si-doped GaN layer, and the second semiconductor layer 13 is a Mg-doped GaN layer.

[0053] Optionally, the light-emitting layer 12 is a multi-quantum well layer, comprising multiple pairs of alternately stacked InGaN layers and GaN layers. Depending on the wavelength range of the LED, different materials can be used for the light-emitting layer 12. For example, the light-emitting layer 12 of a blue-green LED can be made of multiple pairs of alternately stacked InGaN layers and GaN layers; the light-emitting layer 12 of a red LED can be made of multiple pairs of alternately stacked AlGaInP quantum barrier layers and AlGaInP quantum well layers, wherein the Al content of the AlGaInP quantum barrier layers is greater than that of the AlGaInP quantum well layers.

[0054] Exemplarily, the light emitting layer 12 includes 3 to 8 pairs of alternately stacked InGaN layers and GaN layers, for example, 5 pairs of alternately stacked InGaN layers and GaN layers, and other numbers of pairs are also possible, which is not limited in the present disclosure.

[0055] Optionally, the LED further includes a connecting electrode layer, which is located on a surface of the protective layer 40 away from the substrate 60. The connecting electrode layer includes a first connecting electrode 70 and a second connecting electrode 71. The first connecting electrode 70 and the second connecting electrode 71 are insulated from each other. The first connecting electrode 70 penetrates the protective layer 40 and the first insulating layer 20 in the groove 14 and is connected to the first semiconductor layer 11 at the bottom surface 141 of the groove 14. The second connecting electrode 71 penetrates the protective layer 40 and is connected to the metal reflective layer 30. The connecting electrode layer can improve the lateral expansion capability of the current, allowing the current to spread more evenly laterally to various regions of the light-emitting structure 10, thereby improving the radiative recombination efficiency of the carriers and improving the luminous efficiency of the LED.

[0056] like Figure 2 As shown, the first connection electrode 70 includes a block-shaped first sub-electrode 701 and at least two strip-shaped second sub-electrodes 702. The at least two second sub-electrodes 702 are arranged in a first direction x, with the length direction of the second sub-electrode 702 being parallel to the second direction y. One end of the second sub-electrode 702 is connected to the first sub-electrode 701. The second connection electrode 71 includes a connecting portion 711 and at least two strip-shaped portions 712. The at least two strip-shaped portions 712 are arranged in a first direction x, with the length direction of the strip-shaped portions 712 being parallel to the second direction y. One end of the strip-shaped portion 712 is connected to the connecting portion 711.

[0057] Exemplarily, the first direction x is perpendicular to the second direction y.

[0058] For example, the second sub-electrodes 702 and the strip portions 712 are alternately arranged along the first direction x. Thus, when the LED is forward-conducting, the second sub-electrodes 702 and the strip portions 712 are respectively used to electrically connect to external power supplies of different polarities, thereby increasing the uniformity of the LED current distribution.

[0059] In the embodiment of the present disclosure, the first connecting electrode 70 includes a block-shaped first sub-electrode 701 and five strip-shaped second sub-electrodes 702, the second connecting electrode 71 includes a connecting portion 711 and six strip-shaped portions 712, and the five strip-shaped second sub-electrodes 702 and the six strip-shaped portions 712 are alternately arranged along the first direction x.

[0060] In other embodiments, the first connecting electrode 70 may include fewer or more strip-shaped second sub-electrodes 702; or, the second connecting electrode 71 may include fewer or more strip-shaped portions 712; or, the strip-shaped second sub-electrodes 702 and the strip-shaped portions 712 may also be arranged in other ways, etc., and the present disclosure does not limit this.

[0061] Exemplarily, the orthographic projection of the block-shaped first sub-electrode 701 on the first semiconductor layer 11 can be a rounded rectangle, the orthographic projection of the strip-shaped second sub-electrode 702 on the first semiconductor layer 11 can be a finger-shaped, and the orthographic projection of the strip-shaped portion 712 on the first semiconductor layer 11 can be a finger-shaped.

[0062] In other embodiments, the first connection electrode 70 and the second connection electrode 71 may also be in other shapes, which is not limited in the present disclosure.

[0063] Optionally, the connecting electrode layer further includes an anti-thrust electrode 72 , which is insulated from the first connecting electrode 70 and the second connecting electrode 71 . The orthographic projection of the anti-thrust electrode 72 on the first semiconductor layer 11 is located at the geometric center of the surface of the first semiconductor layer 11 .

[0064] Exemplarily, the anti-ejection electrode 72 is truncated cone-shaped and has an annular groove around it. The annular groove insulates the anti-ejection electrode 72 from the second sub-electrode 702. Thus, when the LED is conducting in the forward direction, the anti-ejection electrode 72 does not participate in the conduction and is non-polar. During the LED die bonding process, a pin is used to apply pressure to the LED to secure it, and the location where the pin applies pressure is the geometric center of the LED surface. The non-polarity of the anti-ejection electrode 72 reduces the chance of leakage from the connecting electrode layer caused by the pin breaking through the insulating film layer at the center during die bonding, thereby ensuring LED reliability.

[0065] In other embodiments, the anti-thrust electrode 72 may also be in other shapes, such as cylindrical, rectangular, etc., which is not limited in the present disclosure.

[0066] See also Figure 1 and Figure 2 The LED further includes a second insulating layer 80, which is located on a surface of the connection electrode layer away from the light-emitting structure 10 and a surface of the protective layer 40 away from the light-emitting structure 10. The second insulating layer 80 has a first opening 81 exposing the first connection electrode 70 and a second opening 82 exposing the second connection electrode 71. The first connection electrode 70 and the second connection electrode 71 are insulated by the second insulating layer 80. The second insulating layer 80 protects the connection electrode layer and improves the reliability of the LED.

[0067] Alternatively, the second insulating layer 80 may be a DBR layer. Exemplarily, the DBR layer includes a plurality of SiO2 layers and a plurality of Ti3O5 layers periodically and alternately stacked. The number of periods in the DBR layer may be 20 to 50. For example, the DBR layer may include 30 SiO2 layers and 30 Ti3O5 layers periodically and alternately stacked.

[0068] In other embodiments, the second insulating layer 80 may be at least one of a SiO 2 layer, an Al 2 O 3 layer, a SiN layer, or a SiON layer. For example, the second insulating layer 80 may be a SiO 2 layer.

[0069] Optionally, the LED further includes a pad electrode layer, the pad electrode layer including a first pad electrode 90 and a second pad electrode 91. The first pad electrode 90 is located in the first opening 81 and connected to the first connection electrode 70, and the second pad electrode 91 is located in the second opening 82 and connected to the second connection electrode 71. The pad electrode layer is used to connect to an external electrical signal, which facilitates the injection of carriers into the light-emitting structure 10 through the pad electrode layer and the connection electrode layer.

[0070] Exemplarily, the outer contour of the orthographic projection of the first pad electrode 90 on the first semiconductor layer 11 is the same as the shape of the outer contour of the orthographic projection of the first opening 81 on the first semiconductor layer 11, and the outer contour of the orthographic projection of the second pad electrode 91 on the first semiconductor layer 11 is the same as the shape of the outer contour of the orthographic projection of the second opening 82 on the first semiconductor layer 11.

[0071] Optionally, the pad electrode layer is made of at least one of Cr, Al, Ti, Ni, Pt, Au, AlCu alloy and AuSn alloy.

[0072] Figure 3 This is a flow chart of a method for preparing an LED provided by an embodiment of the present disclosure. Figure 3 As shown, the preparation method comprises:

[0073] In step S1001 , a light-emitting structure is provided.

[0074] The light emitting structure includes a first semiconductor layer, a light emitting layer, and a second semiconductor layer stacked in sequence.

[0075] In step S1002 , a first insulating layer is formed on the second semiconductor layer.

[0076] The first insulating layer has a plurality of through holes.

[0077] In step S1003 , a metal reflective layer is formed on the first insulating layer.

[0078] The metal reflective layer is located on the surface of the first insulating layer away from the light-emitting structure and is electrically connected to the second semiconductor layer through multiple through holes. The orthographic projection of the metal reflective layer on the first semiconductor layer is located inside the outer contour of the orthographic projection of the first insulating layer on the first semiconductor layer and includes the orthographic projection of the second semiconductor layer on the first semiconductor layer.

[0079] The beneficial effects of the embodiment of the present disclosure are the same as those of the structural embodiment and will not be repeated here.

[0080] Figure 4 This is a flow chart of another method for preparing LEDs provided by the embodiment of the present disclosure. Figure 4 As shown, the preparation method comprises:

[0081] In step S2001 , a light emitting structure is formed on a substrate.

[0082] Optionally, the substrate may be a sapphire substrate.

[0083] For example, the sapphire substrate may be pre-treated first, placed in a metal-organic chemical vapor deposition (MOCVD) reaction chamber, and baked for 12 to 18 minutes to clean the sapphire substrate.

[0084] Exemplarily, the light-emitting structure includes a first semiconductor layer, a light-emitting layer, and a second semiconductor layer stacked in sequence. A photoresist structure can be obtained on the surface of the second semiconductor layer away from the light-emitting layer by processes such as photoresist coating, exposure, and development, and the surface of the second semiconductor layer away from the light-emitting layer is etched using the photoresist structure as a mask by methods such as inductively coupled plasma (ICP) etching. The etching depth extends from the surface of the second semiconductor layer away from the light-emitting layer to the first semiconductor layer. After removing the photoresist structure, multiple grooves exposing the first semiconductor layer are formed.

[0085] Optionally, before forming the light-emitting structure, a buffer layer may be formed on the substrate.

[0086] In step S2002 , a transparent conductive layer is formed on the second semiconductor layer.

[0087] For example, an initial ITO layer can be deposited on the entire surface of the second semiconductor layer, and a photoresist structure can be obtained on the initial ITO layer through processes such as photoresist coating, exposure, and development. The initial ITO layer is etched by ITO etching solution using the photoresist structure as a mask, and a transparent conductive layer is formed after removing the photoresist structure.

[0088] In step S2003 , a first insulating layer is formed on the transparent conductive layer.

[0089] For example, an initial current blocking layer and an initial insulating reflective layer can be deposited on the entire surface of the transparent conductive layer, and a photoresist structure is obtained on the initial insulating reflective layer through processes such as photoresist coating, exposure, and development. The initial insulating reflective layer and the initial current blocking layer are etched using the photoresist structure as a mask. After removing the photoresist structure, a stacked current blocking layer and an insulating reflective layer are formed to obtain a first insulating layer, and the first insulating layer has multiple through holes.

[0090] It should be noted that, when no transparent conductive layer is provided, the above steps S2002 and S2003 are to provide a first insulating layer on the second semiconductor layer.

[0091] In step S2004 , a metal reflective layer is formed on the first insulating layer.

[0092] For example, a photoresist structure can be obtained on the first insulating layer through processes such as photoresist coating, exposure, and development, and a metal reflective layer can be formed through a sputtering process and a stripping process using the photoresist structure as a mask. The metal reflective layer is connected to the transparent conductive layer through multiple through holes.

[0093] In step S2005 , a protective layer is formed on the metal reflective layer.

[0094] For example, an initial Al2O3 layer can be deposited entirely on the metal reflective layer using atomic layer deposition (ALD) technology, and then an initial SiO2 layer can be deposited entirely on the initial Al2O3 layer using plasma enhanced chemical vapor deposition (PECVD) technology. A photoresist structure is formed on the initial SiO2 layer through processes such as photoresist coating, exposure, and development. The initial SiO2 layer and the initial Al2O3 layer are etched using the photoresist structure as a mask. After removing the photoresist structure, a protective layer is formed. The protective layer is located on the surface of the metal reflective layer away from the first insulating layer and on the sidewalls of the metal reflective layer. Part of the protective layer is located on the surface of the first insulating layer and connected to the first insulating layer.

[0095] In step S2006 , a connection electrode layer is formed on the protection layer.

[0096] Illustratively, a photoresist structure can be obtained on the protective layer through processes such as photoresist coating, exposure, and development, and a connecting electrode layer is formed by using the photoresist structure as a mask through an electron beam evaporation process and a stripping and degumming process. The connecting electrode layer includes a first connecting electrode and a second connecting electrode, and the first connecting electrode and the second connecting electrode are insulated. The first connecting electrode penetrates the protective layer and the first insulating layer in the groove and is connected to the first semiconductor layer at the bottom surface of the groove, and the second connecting electrode penetrates the protective layer and is connected to the metal reflective layer.

[0097] In step S2007 , a second insulating layer is formed on the connection electrode layer.

[0098] Exemplarily, an initial insulating layer can be deposited on the entire surface of the connecting electrode layer and the protective layer, and a photoresist structure is obtained on the initial insulating layer through processes such as photoresist coating, exposure, and development. The initial insulating layer is etched using the photoresist structure as a mask, and a second insulating layer is formed after removing the photoresist structure. The second insulating layer has a first opening exposing the first connecting electrode and a second opening exposing the second connecting electrode, and the first connecting electrode and the second connecting electrode are insulated by the second insulating layer.

[0099] In step S2008 , a pad electrode layer is formed.

[0100] Illustratively, a photoresist structure can be obtained on the surface of the product obtained in step S2007 through processes such as photoresist coating, exposure, and development, and a pad electrode layer is formed by an electron beam evaporation process and a stripping process using the photoresist structure as a mask. The pad electrode layer includes a first pad electrode and a second pad electrode. The first pad electrode is located in the first opening and is connected to the first connecting electrode, and the second pad electrode is located in the second opening and is connected to the second connecting electrode.

[0101] Optionally, the structure, material and shape of each layer can be found in Figure 1 and Figure 2 Detailed description of the related embodiments is omitted here.

[0102] The embodiment of the present disclosure also provides a light-emitting panel, which includes a light-emitting functional layer and a driving backplane. The light-emitting functional layer is located on the surface of the driving backplane and is electrically connected to the driving backplane. The light-emitting functional layer includes a plurality of the aforementioned LEDs.

[0103] Optionally, the light-emitting panel can be an organic light-emitting diode (OLED) panel, a quantum dot light-emitting diode (QLED) panel, a micro light-emitting diode (Micro LED) panel or a liquid crystal (LC) panel, etc., which have light-emitting functions.

[0104] The above description does not limit the present disclosure in any form. Although the present disclosure has been disclosed as above through the embodiments, it is not intended to limit the present disclosure. Any technician familiar with the profession can make some changes or modifications to equivalent embodiments with equivalent changes using the technical content disclosed above without departing from the scope of the technical solution of the present disclosure. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present disclosure without departing from the content of the technical solution of the present disclosure are still within the scope of the technical solution of the present disclosure.

Claims

1. A light emitting diode, characterized in that: It comprises a light emitting structure (10), a first insulating layer (20) and a metal reflective layer (30), The light emitting structure (10) comprises a first semiconductor layer (11), a light emitting layer (12), and a second semiconductor layer (13) stacked in sequence; The first insulating layer (20) is located on a surface of the second semiconductor layer (13) away from the light-emitting layer (12), and the first insulating layer (20) has a plurality of through holes (21); The metal reflective layer (30) is located on a surface of the first insulating layer (20) away from the light emitting structure (10), and is electrically connected to the second semiconductor layer (13) through the plurality of through holes (21); the orthographic projection of the metal reflective layer (30) on the first semiconductor layer (11) is located inside the outer contour of the orthographic projection of the first insulating layer (20) on the first semiconductor layer (11), and includes the orthographic projection of the second semiconductor layer (13) on the first semiconductor layer (11).

2. The light emitting diode according to claim 1, characterized in that The light emitting structure (10) has a first side wall (101), the first insulating layer (20) has a first portion (201), the first portion (201) is located on a surface of the first side wall (101), and a portion of the metal reflective layer (30) is located on a surface of the first portion (201) away from the first side wall (101).

3. The light emitting diode according to claim 2, characterized in that The light emitting structure (10) has a plurality of grooves (14) extending from a surface of the second semiconductor layer (13) away from the light emitting layer (12) toward the first semiconductor layer (11), the sidewalls of the grooves (14) being the first sidewalls (101), and an angle between a surface of the metal reflective layer (30) on the first portion (201) and a bottom surface (141) of the grooves (14) being 30° to 60°.

4. The light emitting diode according to claim 3, characterized in that The orthographic projection of the light-emitting layer (12) on the first semiconductor layer (11) is located inside the orthographic projection of the metal reflective layer (30) on the first semiconductor layer (11).

5. The light emitting diode according to any one of claims 1 to 4, characterized in that: The through hole (21) is a tapered hole, and the large end of the tapered hole is away from the surface of the second semiconductor layer (13).

6. The light emitting diode according to any one of claims 1 to 4, characterized in that: The first insulating layer (20) comprises a current blocking layer (22) and an insulating reflective layer (23) which are sequentially stacked in a direction away from the light emitting structure (10).

7. The light emitting diode according to any one of claims 1 to 4, characterized in that: The light emitting diode further comprises a protective layer (40), wherein the protective layer (40) is located on a surface of the metal reflective layer (30) away from the first insulating layer (20) and on a side wall of the metal reflective layer (30).

8. The light emitting diode according to claim 7, characterized in that The protective layer (40) comprises an Al2O3 layer and a SiO2 layer stacked in sequence in a direction away from the metal reflective layer (30).

9. The light emitting diode according to claim 7, characterized in that The light emitting diode further comprises a substrate (60), a transparent conductive layer (50), a connecting electrode layer, a second insulating layer (80) and a pad electrode layer. The substrate (60) is located on a surface of the light-emitting structure (10) away from the first insulating layer (20); The transparent conductive layer (50) is located between the second semiconductor layer (13) and the first insulating layer (20), and the metal reflective layer (30) is connected to the transparent conductive layer (50) through the plurality of through holes (21); The connecting electrode layer is located on a surface of the protective layer (40) away from the substrate (60), and comprises a first connecting electrode (70) and a second connecting electrode (71), wherein the first connecting electrode (70) penetrates the first insulating layer (20) and the protective layer (40) and is connected to the first semiconductor layer (11), and the second connecting electrode (71) penetrates the protective layer (40) and is connected to the metal reflective layer (30); The second insulating layer (80) is located on a surface of the connecting electrode layer away from the light emitting structure (10) and a surface of the protective layer (40) away from the light emitting structure (10); The pad electrode layer includes a first pad electrode (90) and a second pad electrode (91), wherein the first pad electrode (90) passes through the second insulating layer (80) and is connected to the first connecting electrode (70), and the second pad electrode (91) passes through the second insulating layer (80) and is connected to the second connecting electrode (71).

10. A light-emitting panel, characterized in that: It comprises a light-emitting functional layer and a driving backplane, wherein the light-emitting functional layer is located on the surface of the driving backplane and is electrically connected to the driving backplane, and the light-emitting functional layer comprises a plurality of light-emitting diodes according to any one of claims 1 to 9.

Images