Micro light-emitting diode and preparation method thereof, display panel and display device

Abstract

The invention discloses a micro light-emitting diode and a preparation method thereof, a display panel and a display device, and relates to the technical field of display, a plurality of concave parts are arranged on the light-emitting surface of the micro light-emitting diode, the light-emitting surface is made to be a roughened surface, the light-emitting efficiency and the light-emitting uniformity of the micro light-emitting diode are improved, and meanwhile the light-emitting efficiency of the micro light-emitting diode is improved. A convex part is arranged on the light-emitting surface of the micro light-emitting diode, and when the convex part at least partially surrounds the plurality of concave parts, the convex part can be used for preventing black ink from climbing to the light-emitting surface of the micro light-emitting diode; when the convex parts and the concave parts are arranged in a staggered manner, the convex parts can be utilized to improve the hydrophobicity of the light-emitting surface of the micro light-emitting diode, reduce the siphonic effect of the light-emitting surface of the micro light-emitting diode on black ink, and reduce the phenomenon that the black ink climbs to the light-emitting surface of the micro light-emitting diode; part of the convex parts at least partially surround the plurality of concave parts, and part of the convex parts and the concave parts are arranged in a staggered manner; therefore, normal light emission of the micro light-emitting diode is ensured.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to a micro light emitting diode and a preparation method thereof, a display panel and a display device. Background Art

[0002] Micro-LED (Micro Light Emitting Diode) has the advantages of high brightness, high contrast, high color gamut, high reliability, etc., and is currently a hot research for the next generation of display light sources. However, micro-LEDs also have the problem of low luminous efficiency, resulting in high power consumption and easy heating. In order to improve the luminous efficiency of micro-LEDs, a PSS (Patterned Sapphire Substrate) structure or a roughened structure is usually set on the light-emitting surface of the micro-LED. The common PSS structure is an inverted cone arranged in an array, and the roughened structure is a randomly distributed rough microstructure.

[0003] In the micro-LED display panel, after the transfer of the micro-LEDs is completed, black ink is usually printed between the micro-LEDs through an inkjet printing process, and the fluidity of the black ink is used to level the micro-LEDs to achieve the purpose of reducing reflection and fixing the micro-LEDs. Although the design height of the black ink does not exceed the micro-LEDs, the black ink will still climb to the top of the micro-LEDs, affecting the light output of the micro-LEDs and deteriorating the light output efficiency of the micro-LEDs.

[0004] Therefore, how to reduce the black ink from climbing to the top of the micro-LED and ensure the normal light emission of the micro-LED is a technical problem that needs to be solved urgently by those skilled in the art. Summary of the invention

[0005] To solve the above technical problems, the embodiments of the present application provide a micro-LED and a preparation method thereof, a display panel and a display device to reduce the black ink from climbing to the top of the micro-LED and ensure the normal light emission of the micro-LED.

[0006] To achieve the above objectives, the present application provides the following technical solutions:

[0007] In a first aspect, an embodiment of the present application provides a micro light emitting diode, the micro light emitting diode comprising:

[0008] A semiconductor stack, the semiconductor stack includes a first surface and a second surface arranged opposite to each other, the first surface includes a platform portion and a plurality of recessed portions recessed toward the second surface relative to the platform portion, the first surface also includes a protruding portion protruding relative to the platform portion in a direction away from the second surface, the protruding portion at least partially surrounds the plurality of recessed portions, and / or the protruding portion and the recessed portions are arranged alternately.

[0009] In a second aspect, an embodiment of the present application provides a display panel, the display panel comprising:

[0010] An array substrate;

[0011] A plurality of micro-LEDs bonded to the array substrate, the micro-LEDs being the above-mentioned micro-LEDs, and the first surfaces of the micro-LEDs being away from the array substrate relative to the second surfaces of the micro-LEDs;

[0012] The light shielding layer is located on the array substrate and between the micro-LEDs, and the height of the light shielding layer relative to the array substrate is smaller than the height of the first surface of the micro-LEDs relative to the array substrate.

[0013] In a third aspect, an embodiment of the present application provides a display device, which includes the above-mentioned display panel.

[0014] In a fourth aspect, an embodiment of the present application provides a method for preparing a micro light emitting diode, the method for preparing a micro light emitting diode comprising:

[0015] providing a substrate;

[0016] Etching a surface of the substrate to form a plurality of raised pattern structures;

[0017] Grooving the surface of the substrate having the convex pattern structure to form a groove pattern structure, wherein the groove pattern structure at least partially surrounds the plurality of convex pattern structures, and / or the groove pattern structure and the convex pattern structure are arranged alternately;

[0018] A non-doped semiconductor layer, a first-type semiconductor layer, an active layer, and a second-type semiconductor layer are sequentially formed on the surface of the substrate having the convex pattern structure and the concave pattern structure, and a platform portion, a plurality of concave portions, and a convex portion are formed on the surface of the non-doped semiconductor layer facing the substrate, wherein the concave portion corresponds to the convex pattern structure, the convex portion corresponds to the convex pattern structure, the convex portion at least partially surrounds the plurality of concave portions, and / or the convex portion and the concave portion are alternately arranged;

[0019] Etching the active layer and the second-type semiconductor layer so that the active layer and the second-type semiconductor layer expose a portion of the first-type semiconductor layer;

[0020] Forming a first electrode on a surface of the first-type semiconductor layer exposed to the active layer and the second-type semiconductor layer, and forming a second electrode on a surface of the second-type semiconductor layer away from the active layer;

[0021] Peel off the substrate.

[0022] Compared with the prior art, the above technical solution has the following advantages:

[0023] The micro-light-emitting diode provided in the embodiment of the present application includes a semiconductor stack, and the semiconductor stack includes a first surface and a second surface arranged opposite to each other, the first surface is a light-emitting surface, and the first surface includes a platform portion and a plurality of recessed portions recessed toward the second surface relative to the platform portion. By arranging a plurality of recessed portions on the first surface, the first surface is made into a roughened surface, thereby improving the light-emitting efficiency and uniformity of the micro-light-emitting diode; further, a convex portion convex relative to the platform portion in a direction away from the second surface is also arranged on the first surface, the convex portion at least partially surrounds the plurality of recessed portions, and / or the convex portion and the recessed portion are arranged alternately; when the convex portion at least partially surrounds the plurality of recessed portions, the convex portion can be used to prevent black ink from climbing to the first surface of the semiconductor stack of the micro-light-emitting diode; when the convex portion and the recessed portion are arranged alternately, the convex portion can be used to reduce the first surface of the semiconductor stack of the micro-light-emitting diode; The surface energy of the surface can improve the hydrophobicity of the first surface of the semiconductor stack of the micro-light-emitting diode, reduce the siphon effect of the first surface of the semiconductor stack of the micro-light-emitting diode on the black ink, and reduce the black ink crawling to the first surface of the semiconductor stack of the micro-light-emitting diode; when some of the raised portions at least partially surround a plurality of recessed portions, and some of the raised portions and the recessed portions are arranged in an alternating manner, the raised portions can be used to block the black ink from crawling to the first surface of the semiconductor stack of the micro-light-emitting diode, and the raised portions can be used to reduce the surface energy of the first surface of the semiconductor stack of the micro-light-emitting diode, thereby improving the hydrophobicity of the first surface of the semiconductor stack of the micro-light-emitting diode, reducing the siphon effect of the first surface of the semiconductor stack of the micro-light-emitting diode on the black ink, and reducing the black ink crawling to the first surface of the semiconductor stack of the micro-light-emitting diode; thereby ensuring the normal light emission of the micro-light-emitting diode. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 It is a schematic diagram of a partial cross-sectional structure of an existing micro-light emitting diode display panel;

[0026] Figure 2 The electron micrograph of a local cross section of an existing micro light emitting diode display panel;

[0027] Figure 3 A schematic cross-sectional structure diagram of a micro light emitting diode and a display panel including the micro light emitting diode provided in an embodiment of the present application;

[0028] Figure 4A schematic diagram of a first surface of a semiconductor stack of a micro light emitting diode provided in an embodiment of the present application;

[0029] Figure 5 A schematic cross-sectional view of an epitaxial structure of a semiconductor stack;

[0030] Figure 6 A schematic diagram of a first surface of another semiconductor stack of a micro light emitting diode provided in an embodiment of the present application;

[0031] Figure 7 A schematic cross-sectional structure diagram of another micro light emitting diode and a display panel including the micro light emitting diode provided in an embodiment of the present application;

[0032] Figure 8 A schematic diagram of a first surface of a semiconductor stack of another micro light emitting diode provided in an embodiment of the present application;

[0033] Fig. 9 A schematic cross-sectional structure diagram of another micro light emitting diode and a display panel including the micro light emitting diode provided in an embodiment of the present application;

[0034] Fig.10 A schematic diagram of a first surface of a semiconductor stack of another micro light emitting diode provided in an embodiment of the present application;

[0035] Fig.11 A schematic cross-sectional structure diagram of another micro light emitting diode and a display panel including the micro light emitting diode provided in an embodiment of the present application;

[0036] Fig.12 A schematic diagram of a first surface of a semiconductor stack of another micro light emitting diode provided in an embodiment of the present application;

[0037] Fig.13 A schematic cross-sectional structure diagram of another micro light emitting diode and a display panel including the micro light emitting diode provided in an embodiment of the present application;

[0038] Fig.14 A schematic cross-sectional structure diagram of another micro light emitting diode and a display panel including the micro light emitting diode provided in an embodiment of the present application;

[0039] Fig.15 A schematic diagram of a first surface of a semiconductor stack of another micro light emitting diode provided in an embodiment of the present application;

[0040] Fig.16 A schematic diagram of a first surface of a semiconductor stack of another micro light emitting diode provided in an embodiment of the present application;

[0041] Fig.17A schematic cross-sectional structure diagram of another micro light emitting diode and a display panel including the micro light emitting diode provided in an embodiment of the present application;

[0042] Fig.18 A schematic cross-sectional structure diagram of another micro light emitting diode provided in an embodiment of the present application;

[0043] Fig.19 A schematic diagram of a process for preparing a micro light-emitting diode provided in an embodiment of the present application;

[0044] Figure 20a-Figure 20e This is a schematic structural diagram corresponding to each process step in a method for preparing a micro light emitting diode provided in an embodiment of the present application.

[0045] Fig.21 A schematic top view of a display device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0046] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0047] The terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and need not be used to describe a specific order or sequential order. It should be understood that the terms used in this way can be interchangeable under appropriate circumstances, which is only to describe the distinction mode adopted by the objects of the same attributes when describing in the embodiments of the present application. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, so that the process, method, system, product or equipment comprising a series of units need not be limited to those units, but may include other units that are not clearly listed or inherent to these processes, methods, products or equipment.

[0048] Figure 1 FIG. 4 shows a partial cross-sectional structure diagram of an existing micro-LED display panel. Figure 1As shown, in the micro-LED display panel, after the micro-LED 01 is transferred to the substrate 02, the black ink 03 is usually printed between the micro-LEDs 01 through an inkjet printing process, and the black ink 03 is leveled by the fluidity of the black ink 03 to achieve the purpose of reducing reflection and fixing the micro-LED 01. Then, the packaging glue 03 and the packaging film / cover plate 04 are sequentially arranged on the side of the micro-LED 01 away from the substrate 02 to complete the packaging of the micro-LED 01. In fact, although the design height of the black ink 03 does not exceed the micro-LED 01, the black ink 03 will still climb to the top of the micro-LED 01, affecting the light output of the micro-LED 01 and deteriorating the luminous efficiency of the micro-LED 01.

[0049] Figure 2 A partial cross-sectional electron micrograph of an existing micro-LED display panel is shown in FIG. Figure 2 As shown, it can be clearly seen that the black ink 03 will climb to the top of the micro-LED 01 and block the light emitted by the micro-LED 01.

[0050] As described in the background technology section, how to reduce the black ink from climbing to the top of the micro-LED and ensure the normal light emission of the micro-LED is a technical problem that needs to be solved urgently by those skilled in the art.

[0051] The inventors found that the design height of the black ink does not exceed the micro-LED, and the reason why the black ink climbs to the top of the micro-LED is that the top of the micro-LED is provided with a PSS structure or a roughened structure, which makes the top of the micro-LED have a strong affinity for the black ink, and the black ink will be siphoned to the top of the micro-LED. However, we know that the PSS structure or the roughened structure on the light-emitting surface of the micro-LED is crucial to improving the light-emitting efficiency of the micro-LED.

[0052] In view of this, the present application embodiment provides a micro light emitting diode 100, Figure 3 FIG. 1 shows a schematic cross-sectional structure diagram of a micro light emitting diode 100 provided in an embodiment of the present application. Figure 3 As shown, the micro LED 100 includes a semiconductor stack 110 , which is used for emitting light. The semiconductor stack 110 includes a first surface S1 and a second surface S2 that are oppositely disposed. The first surface S1 is a light emitting surface of the micro LED 100 .

[0053] Figure 4 A schematic diagram of a first surface S1 of a semiconductor stack 110 of a micro-LED 100 provided in an embodiment of the present application is shown, combined with Figure 3 and Figure 4As shown, the first surface S1 of the semiconductor stack 110 includes a terrace portion D1 and a plurality of recessed portions D2 recessed toward the second surface S2 relative to the terrace portion D1 .

[0054] Optionally, the recessed portion D2 may be a PSS structure. Figure 5 As shown, Figure 5 A cross-sectional schematic diagram of an epitaxial structure of a semiconductor stack 110 is shown. It can be seen that when preparing a micro-light-emitting diode 100, a convex pattern structure T1 can be first produced on a substrate 10 such as sapphire through an etching process, and then a semiconductor stack 110 is formed on the surface of the substrate 10 having the convex pattern structure T1, so that the surface of the semiconductor stack 110 facing the substrate 10 (i.e., the first surface S1) has a platform portion D1 and a plurality of recessed portions D2 recessed toward the inside of the semiconductor stack 110 relative to the platform portion D1. Subsequently, after the prepared light-emitting diode 100 is transferred to an array substrate from the side of the surface of the semiconductor stack 110 facing away from the substrate 10 (i.e., the second surface S2), the first surface S1 of the semiconductor stack 110 includes the platform portion D1 and a plurality of recessed portions D2 recessed toward the second surface S2 relative to the platform portion D1. These recessed portions D2 are called a PSS structure.

[0055] Alternatively, the recessed portion D2 may also be a randomly distributed recessed microstructure.

[0056] It is understandable that since the first surface S1 is the light emitting surface of the micro LED 100 , by providing a plurality of recessed portions D2 on the first surface S1 , the first surface S1 is made a roughened surface, thereby improving the light emitting efficiency and uniformity of the micro LED 100 .

[0057] Combination Figure 3 and Figure 4 As shown, the first surface S1 of the semiconductor stack 110 further includes a protruding portion D3 protruding relative to the platform portion D1 in a direction away from the second surface S2. Figure 5 As shown, a groove pattern structure T2 may be first produced on the substrate 10 through an etching process, and then, the surface of the semiconductor stack 110 formed on the substrate 10 facing the substrate 10 (i.e., the first surface S1) may have, in addition to the platform portion D1 and a plurality of recessed portions D2 recessed relative to the platform portion D1, a raised portion D3 raised relative to the platform portion D1.

[0058] On the first surface S1 of the semiconductor stack 110 , the structure of the protrusion D3 and the positional relationship between the protrusion D3 and the plurality of recesses D2 may be in various forms, which are described in detail below.

[0059] The first method is to combine Figure 3 and Figure 4As shown, the raised portion D3 includes a surrounding portion D31 , which at least partially surrounds the plurality of recessed portions D2 .

[0060] Optional, combined Figure 3 and Figure 4 As shown, the enclosure D31 is located around the plurality of recessed portions D2, and the enclosure D31 surrounds the plurality of recessed portions D2. In this way, after the micro-LED 100 is transferred from the second surface S2 side of the semiconductor stack 110 to the array substrate 200, Figure 3 As shown, the blocking portion D31 can prevent the black ink from climbing up to the first surface S1 of the semiconductor stack 110 of the micro-LED 100 from around the plurality of recessed portions D2 .

[0061] Alternatively, combine Figure 3 and Figure 6 As shown, Figure 6 A schematic diagram of the first surface S1 of the semiconductor stack 110 of another micro-LED 100 provided in an embodiment of the present application is shown. It can be seen that the first surface S1 of the semiconductor stack 110 includes four edges connected in sequence to form a rectangle, wherein the first edge S11 and the third edge S13 are arranged opposite to each other, the second edge S12 and the fourth edge S14 are arranged opposite to each other, and the length of the first edge S11 is greater than the length of the second edge S12, that is, the first edge S11 and the third edge S13 are long edges, and the second edge S12 and the fourth edge S14 are short edges; considering that it is more difficult for black ink to crawl over the long edge, while it is easier for black ink to crawl over the short edge, therefore, a blocking portion D31 can be provided at the second edge S12 and the fourth edge S14. With such a configuration, after the micro-LED 100 is transferred from the second surface S2 side of the semiconductor stack 110 to the array substrate 200, refer to Figure 3 As shown, the enclosure D31 can at least block the black ink from crawling from the second edge S12 and the fourth edge S14 to the first surface S1 of the semiconductor stack 110 of the micro-LED 100, and it is relatively difficult for the black ink to crawl over the first edge S11 and the third edge S13 to reach the first surface S1 of the semiconductor stack 110 of the micro-LED 100.

[0062] It should be noted that Figure 4 It only lists the case where the enclosure portion D31 completely surrounds the plurality of recessed portions D2. Figure 6 It only lists the case where the blocking portion D31 is located at two short edge portions of the first surface S1 and surrounds a plurality of recessed portions D2. When the protruding portion D3 includes the blocking portion D31, as long as the blocking portion D31 at least partially surrounds the plurality of recessed portions D2, the blocking portion D31 can, to a certain extent, block the black ink from climbing onto the first surface S1 of the semiconductor stack 110 of the micro-LED 100.

[0063] It can be understood that since the enclosure part D31 is located around a plurality of recessed parts D2, the greater the degree of surrounding of the plurality of recessed parts D2 by the enclosure part D31, the better the effect of the enclosure part D31 in preventing the black ink from climbing onto the first surface S1 of the semiconductor stack 110 of the micro light-emitting diode 100.

[0064] It can also be understood that with reference to Figure 3 as shown, the greater the height h of the enclosure part D31 relative to the platform part D1, the better the effect of the enclosure part D31 in preventing the black ink from climbing onto the first surface S1 of the semiconductor stack 110 of the micro light-emitting diode 100. However, the height h of the enclosure part D31 relative to the platform part D1 should not be too high. Optionally, the height h of the enclosure part D31 relative to the platform part D1 satisfies: 0 μm < h ≤ 2 μm. In this way, the enclosure part D31 is easier to fabricate during the process preparation.

[0065] The second method, in combination with Figure 7 and Figure 8 as shown, Figure 7 shows a schematic cross-sectional structure diagram of another micro light-emitting diode 100 provided by an embodiment of the present application, Figure 8 shows a schematic diagram of the first surface S1 of the semiconductor stack 110 of another micro light-emitting diode 100 provided by an embodiment of the present application. It can be seen that the protrusion part D3 includes a plurality of micro protrusion parts D32.

[0066] On the basis that the protrusion part D3 includes a plurality of micro protrusion parts D32, optionally, in combination with Figure 7 and Figure 8 as shown, the micro protrusion parts D32 are arranged along at least part of the peripheral area of the plurality of recessed parts D2. At this time, the micro protrusion parts D32 are similar to the enclosure part D31 and partially surround or completely surround the plurality of recessed parts D2 in the peripheral area of the plurality of recessed parts D2. With such a setting, the plurality of micro protrusion parts D32 located in the peripheral area of the plurality of recessed parts D2 can not only prevent the black ink from climbing onto the first surface S1 of the semiconductor stack 110 of the micro light-emitting diode 100 to a certain extent; but also reduce the surface energy of the first surface S1 of the semiconductor stack 110 to a certain extent, improve the hydrophobicity of the first surface S1 of the semiconductor stack 110, reduce the siphon effect of the first surface S1 of the semiconductor stack 110 on the black ink, and further reduce the black ink from climbing onto the first surface S1 of the semiconductor stack 110 of the micro light-emitting diode 100; in addition, it can also increase the roughness of the first surface S1 of the semiconductor stack 110 to a certain extent, and further improve the light emission uniformity and luminous efficiency of the micro light-emitting diode 100.

[0067] On the basis that the protrusion part D3 includes a plurality of micro protrusion parts D32, another option is to combine Fig. 9 and Fig.10 As shown, Fig. 9 FIG. 1 shows a cross-sectional structure diagram of another micro light emitting diode 100 provided in an embodiment of the present application. Fig.10 A schematic diagram of the first surface S1 of the semiconductor stack 110 of another micro-LED 100 provided in an embodiment of the present application is shown. It can be seen that the micro-protrusions D32 and the recessed portions D2 are arranged alternately. With this arrangement, the first surface S1 of the semiconductor stack 110 is similar to the surface of a lotus leaf, which can significantly reduce the surface energy of the first surface S1 of the semiconductor stack 110, improve the hydrophobicity of the first surface S1 of the semiconductor stack 110, reduce the siphon effect of the first surface S1 of the semiconductor stack 110 on the black ink, and reduce the black ink climbing to the first surface S1 of the semiconductor stack 110 of the micro-LED 100; and the micro-protrusions D32 arranged alternately with the recessed portions D2 will also enhance the roughness of the first surface S1 of the semiconductor stack 110, further improving the light uniformity and luminous efficiency of the micro-LED 100.

[0068] On the basis that the protrusion D3 includes a plurality of micro-protrusions D32, another option is to combine Fig.11 and Fig.12 As shown, Fig.11 FIG. 1 shows a cross-sectional structure diagram of another micro light emitting diode 100 provided in an embodiment of the present application. Fig.12 A schematic diagram of the first surface S1 of a semiconductor stack 110 of another micro-LED 100 provided in an embodiment of the present application is shown. It can be seen that among the multiple micro-protrusions D32 on the first surface D1 of the semiconductor stack 110, some of the micro-protrusions D32 are arranged along at least part of the peripheral area of ​​the multiple recesses D2, and another part of the micro-protrusions D32 are arranged alternately with the recesses D2. In this way, the multiple micro-protrusions D32 located in the peripheral area of ​​the multiple recessed portions D2 can, to a certain extent, block the black ink from crawling onto the first surface S1 of the semiconductor stack 110 of the micro-LED 100; and, whether it is the micro-protrusions D32 located in the peripheral area of ​​the multiple recessed portions D2 or the micro-protrusions D32 arranged alternately with the recessed portions D2, the surface energy of the first surface S1 of the semiconductor stack 110 can be reduced, the hydrophobicity of the first surface S1 of the semiconductor stack 110 can be improved, the siphon effect of the first surface S1 of the semiconductor stack 110 on the black ink can be reduced, the black ink can be reduced from crawling onto the first surface S1 of the semiconductor stack 110 of the micro-LED 100, and the roughness of the first surface S1 of the semiconductor stack 110 can be enhanced, thereby further improving the light uniformity and luminous efficiency of the micro-LED 100.

[0069] It should be noted that Fig. 9 and Fig.11The cross-sectional view of the micro-LED 100 shown only passes through the micro-protrusion D32 and does not pass through the recessed portion D2. Fig. 9 and Fig.11 The recessed portion D2 is not shown in the figure, and similar situations in other figures of the present application will not be repeated.

[0070] Regarding the multiple micro-protrusions D32 in the first surface S1 that are arranged alternately with the recessed portions D2, since the present application does not limit the arrangement of the multiple recessed portions D2 in the first surface S1, the arrangement of the multiple micro-protrusions D32 in the first surface S1 that are arranged alternately with the recessed portions D2 is also not limited. The micro-protrusions D32 can be interspersed between the recessed portions D2 and arranged alternately with the recessed portions D2.

[0071] Optional, such as Fig.10 and Fig.12 As shown, the recessed portions D2 are arranged in a row along the first direction X, and multiple rows of recessed portions D2 are arranged along the second direction Y. The first direction X and the second direction Y intersect, and the first direction X and the second direction Y are both parallel to the platform portion D1; alternate rows of recessed portions D2 overlap along the second direction Y, and adjacent rows of recessed portions D2 at least partially do not overlap along the second direction Y. In this way, the recessed portions D2 are arranged in a manner similar to a honeycomb, which can make the light output of the micro-LED 100 at various angles more uniform and reduce the color deviation at different angles.

[0072] Further optional, such as Fig.10 and Fig.12 As shown, at least part of the micro-protrusions D32 are arranged in a row along the first direction X, and multiple rows of micro-protrusions D32 are arranged along the second direction Y; the micro-protrusions D32 in alternate rows overlap along the second direction Y, and the micro-protrusions D32 in adjacent rows at least partially do not overlap along the second direction Y. In this way, the micro-protrusions D32 arranged alternately with the recessed portions D2 are also arranged in a honeycomb-like manner, which can further improve the hydrophobicity of the first surface S1 of the semiconductor stack 110, reduce the siphon effect of the first surface S1 of the semiconductor stack 110 on the black ink, and reduce the black ink climbing to the first surface S1 of the semiconductor stack 110 of the micro-LED 100; and further enhance the roughness of the first surface S1 of the semiconductor stack 110, thereby improving the light uniformity and luminous efficiency of the micro-LED 100.

[0073] It should be noted that, in the first surface S1 of the semiconductor stack 110, as long as the plurality of recesses D2 still dominates compared to the plurality of micro-protrusions D32, the plurality of micro-protrusions D32, whether located in the peripheral area of ​​the plurality of recesses D2 or arranged in a staggered manner with the recesses D2, will not only not affect the improvement effect of the plurality of recesses D2 on the light uniformity and light efficiency, but will enhance the roughness of the first surface S1 of the semiconductor stack 110, and further improve the light uniformity and light efficiency of the micro-LED 100. Therefore, optionally, as Figure 8 , Fig.10 as well as Fig.12 As shown, the orthographic projection area of ​​the micro-protrusions D32 on the platform portion D1 is smaller than the orthographic projection area of ​​the recesses D2 on the platform portion D1 , thereby ensuring that the plurality of recesses D2 dominate the first surface S1 of the semiconductor stack 110 compared to the plurality of micro-protrusions D32 .

[0074] On the basis that the protrusion D3 includes a plurality of micro-protrusions D32, optionally, as Figure 7 , Fig. 9 and Fig.11 As shown, the micro-protrusions D32 are columnar, so that the first surface D1 of the semiconductor stack 110 is similar to the surface of a lotus leaf, so as to improve the hydrophobicity of the first surface D1 of the semiconductor stack 110 .

[0075] On the basis that the protrusion D3 includes a plurality of micro-protrusions D32, another option is as follows: Fig.13 As shown, Fig.13 A schematic diagram of the cross-sectional structure of another micro-LED 100 provided in an embodiment of the present application is shown, in which the micro-protrusion D32 may also be mushroom-shaped, so that the first surface D1 of the semiconductor stack 110 is similar to the epidermis of a springtail, so as to improve the hydrophobicity of the first surface D1 of the semiconductor stack 110 .

[0076] The third method, combined Fig.14 and Fig.15 As shown, Fig.14 FIG. 1 shows a cross-sectional structure diagram of another micro light emitting diode 100 provided in an embodiment of the present application. Fig.15A schematic diagram of the first surface S1 of a semiconductor stack 110 of another micro-LED 100 provided in an embodiment of the present application is shown. It can be seen that the raised portion D3 includes a surrounding portion D31 and a plurality of micro-raised portions D32, wherein the surrounding portion D31 at least partially surrounds a plurality of recessed portions D2, and the micro-raised portions D32 are alternately arranged with the recessed portions D2. With such arrangement, not only can the blocking portion D31 be used to prevent the black ink from crawling onto the first surface S1 of the semiconductor stack 110 of the micro-LED 100, but the micro-convex portion D32 can also be used to reduce the surface energy of the first surface S1 of the semiconductor stack 110, thereby increasing the hydrophobicity of the first surface S1 of the semiconductor stack 110 and reducing the siphon effect of the first surface S1 of the semiconductor stack 110 on the black ink, thereby reducing the black ink from crawling onto the first surface S1 of the semiconductor stack 110 of the micro-LED 100; moreover, the micro-convex portions D32 staggered with the recessed portions D2 will also enhance the roughness of the first surface S1 of the semiconductor stack 110, thereby further improving the light uniformity and luminous efficiency of the micro-LED 100.

[0077] The blocking portion D31 in the raised portion D3 is similar to the first embodiment.

[0078] Optional, combined Fig.14 and Fig.15 As shown, the barrier D31 is located around the plurality of recesses D2, and surrounds the plurality of recesses D2. In this way, the barrier D31 can prevent the black ink from climbing to the first surface S1 of the semiconductor stack 110 of the micro-LED 100 from around the plurality of recesses D2.

[0079] Alternatively, combine Fig.14 and Fig.16 As shown, Fig.16Fig. shows a schematic diagram of the first surface S1 of the semiconductor stack 110 of another micro light-emitting diode 100 provided by the embodiments of the present application. It can be seen that the first surface S1 of the semiconductor stack 110 includes four edges connected in sequence to form a rectangle. Among them, the first edge S11 and the third edge S13 are oppositely arranged, the second edge S12 and the fourth edge S14 are oppositely arranged, and the length of the first edge S11 is greater than the length of the second edge S12. That is, the first edge S11 and the third edge S13 are long edges, and the second edge S12 and the fourth edge S14 are short edges. Considering that it is more difficult for the black ink to climb over the long edges, while it is easier for the black ink to climb over the short edges, therefore, the retaining parts D31 can be arranged on the second edge S12 and the fourth edge S14. With such an arrangement, the retaining parts D31 can at least prevent the black ink from climbing from the second edge S12 and the fourth edge S14 to the first surface S1 of the semiconductor stack 110 of the micro light-emitting diode 100, and it is relatively difficult for the black ink to climb over the first edge S11 and the third edge S13 to reach the first surface S1 of the semiconductor stack 110 of the micro light-emitting diode 100.

[0080] It should be noted that Fig.15 only the case where the retaining parts D31 completely surround the plurality of recessed parts D2 is listed, Fig.16 only the case where the retaining parts D31 are located at two short-edge parts of the first surface S1 and surround the plurality of recessed parts D2 is listed. When the protruding parts D3 include the retaining parts D31, as long as the retaining parts D31 at least partially surround the plurality of recessed parts D2, the retaining parts D31 can, to a certain extent, prevent the black ink from climbing to the first surface S1 of the semiconductor stack 110 of the micro light-emitting diode 100.

[0081] It can be understood that since the retaining parts D31 are located around the plurality of recessed parts D2, the greater the degree of surrounding of the plurality of recessed parts D2 by the retaining parts D31, the better the effect of the retaining parts D31 in preventing the black ink from climbing to the first surface S1 of the semiconductor stack 110 of the micro light-emitting diode 100.

[0082] It can also be understood that referring to Fig.14 as shown, the greater the height h of the retaining parts D31 relative to the platform part D1, the better the effect of the retaining parts D31 in preventing the black ink from climbing to the first surface S1 of the semiconductor stack 110 of the micro light-emitting diode 100. However, the height h of the retaining parts D31 relative to the platform part D1 should not be too high. Optionally, the height h of the retaining parts D31 relative to the platform part D1 satisfies: 0μm < h ≤ 2μm. In this way, the retaining parts D31 are easier to prepare during the process preparation.

[0083] The multiple micro-protrusions D32 in the protrusions D3 are similar to the case where the micro-protrusions D32 and the recesses D2 are arranged in an alternating manner in the second manner. Since the present application does not limit the arrangement of the multiple recesses D2 in the first surface S1, the arrangement of the multiple micro-protrusions D32 arranged in an alternating manner with the recesses D2 in the first surface S1 is also not limited. The micro-protrusions D32 can be interspersed between the recesses D2 and arranged in an alternating manner with the recesses D2.

[0084] Optional, such as Fig.15 and Fig.16 As shown, the recessed portions D2 are arranged in a row along the first direction X, and multiple rows of recessed portions D2 are arranged along the second direction Y. The first direction X and the second direction Y intersect, and the first direction X and the second direction Y are both parallel to the platform portion D1; alternate rows of recessed portions D2 overlap along the second direction Y, and adjacent rows of recessed portions D2 at least partially do not overlap along the second direction Y. In this way, the recessed portions D2 are arranged in a manner similar to a honeycomb, which can make the light output of the micro-LED 100 at various angles more uniform and reduce the color deviation at different angles.

[0085] Further optional, such as Fig.15 and Fig.16 As shown, at least part of the micro-protrusions D32 are arranged in a row along the first direction X, and multiple rows of micro-protrusions D32 are arranged along the second direction Y; the micro-protrusions D32 in alternate rows overlap along the second direction Y, and the micro-protrusions D32 in adjacent rows at least partially do not overlap along the second direction Y. In this way, the micro-protrusions D32 arranged alternately with the recessed portions D2 are also arranged in a honeycomb-like manner, which can further improve the hydrophobicity of the first surface S1 of the semiconductor stack 110, reduce the siphon effect of the first surface S1 of the semiconductor stack 110 on the black ink, and reduce the black ink climbing to the first surface S1 of the semiconductor stack 110 of the micro-LED 100; and further enhance the roughness of the first surface S1 of the semiconductor stack 110, thereby improving the light uniformity and luminous efficiency of the micro-LED 100.

[0086] It should be noted that, in the first surface S1 of the semiconductor stack 110, as long as the plurality of recessed portions D2 still dominates compared to the plurality of micro-protrusions D32, the plurality of micro-protrusions D32 will not only not affect the improvement effect of the plurality of recessed portions D2 on the light uniformity and light efficiency, but will enhance the roughness of the first surface S1 of the semiconductor stack 110, and further improve the light uniformity and light efficiency of the micro-LED 100. Therefore, optionally, as Fig.15 and Fig.16 As shown, the orthographic projection area of ​​the micro-protrusions D32 on the platform portion D1 is smaller than the orthographic projection area of ​​the recesses D2 on the platform portion D1 , thereby ensuring that the plurality of recesses D2 dominate the first surface S1 of the semiconductor stack 110 compared to the plurality of micro-protrusions D32 .

[0087] On the basis that the protrusion D3 includes a plurality of micro-protrusions D32, optionally, as Fig.15 As shown, the micro-protrusions D32 are columnar, so that the first surface D1 of the semiconductor stack 110 is similar to the surface of a lotus leaf, so as to improve the hydrophobicity of the first surface D1 of the semiconductor stack 110 .

[0088] On the basis that the protrusion D3 includes a plurality of micro-protrusions D32, another option is as follows: Fig.17 As shown, Fig.17 A schematic diagram of the cross-sectional structure of another micro-LED 100 provided in an embodiment of the present application is shown, in which the micro-protrusion D32 may also be mushroom-shaped, so that the first surface D1 of the semiconductor stack 110 is similar to the epidermis of a springtail, so as to improve the hydrophobicity of the first surface D1 of the semiconductor stack 110 .

[0089] On the basis that the raised portion D3 includes both the blocking portion D31 and a plurality of micro-raised portions D32, optionally, as Fig.14 and Fig.17 As shown, the height of the enclosure D31 relative to the platform D1 is greater than the height of the micro-protrusion D32 relative to the platform D1. In this way, the blocking effect of the enclosure D31 on the black ink and the effect of the multiple micro-protrusions D32 on improving the hydrophobicity of the first surface S1 of the semiconductor stack 110 can be more efficiently superimposed. Specifically, the enclosure D31 is first used to block the black ink from climbing to the first surface S1 of the semiconductor stack 110 of the micro-light-emitting diode 100, and the effect of the multiple micro-protrusions D32 on improving the hydrophobicity of the first surface S1 of the semiconductor stack 110 is further superimposed to prevent the black ink from climbing to the first surface S1 of the semiconductor stack 110 of the micro-light-emitting diode 100.

[0090] In other embodiments of the present application, the height of the enclosure portion D31 relative to the platform portion D1 may also be equal to or less than the height of the micro-protrusion D32 relative to the platform portion D1, and the blocking effect of the enclosure portion D31 on black ink and the effect of multiple micro-protrusions D32 on improving the hydrophobicity of the first surface S1 of the semiconductor stack 110 may also be superimposed.

[0091] In summary, the micro-LED provided in the embodiment of the present application is provided with a protrusion D3 protruding in a direction away from the second surface S2 relative to the platform portion D1 on the first surface S1 of the semiconductor stack 110, and the protrusion D3 at least partially surrounds the plurality of recessed portions D2, and / or the protrusion D3 and the recessed portions D2 are arranged in an alternating manner; when the protrusion D3 at least partially surrounds the plurality of recessed portions D2, the protrusion D3 can be used to prevent the black ink from climbing onto the first surface S1 of the semiconductor stack 110 of the micro-LED 100; when the protrusion D3 and the recessed portions D2 are arranged in an alternating manner, the protrusion D3 can be used to reduce the surface energy of the first surface S1 of the semiconductor stack 110 of the micro-LED 100, improve the hydrophobicity of the first surface S1 of the semiconductor stack 110 of the micro-LED 100, and reduce the resistance of the first surface S1 of the semiconductor stack 110 of the micro-LED 100 to the black ink. The siphon effect can also reduce the black ink from crawling to the first surface S1 of the semiconductor stack 110 of the micro-LED 100; when some of the raised portions D3 at least partially surround the plurality of recessed portions D2, and some of the raised portions D3 and the recessed portions D2 are arranged in an alternating manner, the raised portions D3 can be used to block the black ink from crawling to the first surface S1 of the semiconductor stack 110 of the micro-LED 100, and the raised portions D3 can be used to reduce the surface energy of the first surface S1 of the semiconductor stack 110 of the micro-LED 100, thereby improving the hydrophobicity of the first surface S1 of the semiconductor stack 110 of the micro-LED 100, reducing the siphon effect of the first surface S1 of the semiconductor stack 110 of the micro-LED 100 on the black ink, and further reducing the black ink from crawling to the first surface S1 of the semiconductor stack 110 of the micro-LED 100; thereby ensuring the normal light emission of the micro-LED 100.

[0092] In the above-mentioned embodiments, the semiconductor stack 110 in the micro-LED 100 is regarded as a whole. Specifically, Fig.18 As shown, Fig.18The cross-sectional structure diagram of another micro-LED 100 provided in an embodiment of the present application is shown. It can be seen that the semiconductor stack 110 includes a non-doped semiconductor layer 111, a first-type semiconductor layer 112, an active layer 113, and a second-type semiconductor layer 114 stacked in sequence. The active layer 113 and the second-type semiconductor layer 114 expose a portion of the first-type semiconductor layer 112; the surface of the non-doped semiconductor layer 111 away from the first-type semiconductor layer 112 is the first surface S1, the surface of the second-type semiconductor layer 114 away from the active layer 113, and the surface of the active layer 113 and the second-type semiconductor layer 114 are the first surface S2. The surface of the first-type semiconductor layer 112 exposed by the second-type semiconductor layer 114 is the second surface S2; wherein the first surface S1 includes a platform portion D1, a plurality of recessed portions D2 recessed toward the second surface S2 relative to the platform portion D1, and a raised portion D3 raised relative to the platform portion D1 in a direction away from the second surface D2; in the second surface S2, the surfaces of the first-type semiconductor layer 112 exposed by the active layer 113 and the second-type semiconductor layer 114 are provided with a first electrode M1, and the surface of the second-type semiconductor layer 114 away from the active layer 113 is provided with a second electrode M2.

[0093] Accordingly, the present application also provides a method for preparing a micro light emitting diode, referring to Fig.19 As shown, Fig.19 A schematic flow chart of a method for preparing a micro light-emitting diode provided in an embodiment of the present application is shown. The method for preparing a micro light-emitting diode includes:

[0094] S100: Reference Fig.20a As shown, a substrate 10 is provided.

[0095] Optionally, the substrate 10 may be a sapphire substrate.

[0096] S200: Reference Fig.20b As shown, a surface of the substrate 10 is etched to form a plurality of protruding pattern structures T1.

[0097] S300: Reference Fig.20c As shown, the surface of the substrate 10 having the protruding pattern structure T1 is grooved to form a recessed pattern structure T2, wherein the recessed pattern structure T2 at least partially surrounds the plurality of protruding pattern structures T1, and / or the recessed pattern structure T2 and the protruding pattern structure T1 are alternately arranged.

[0098] S400: Reference Fig.20dAs shown, a non-doped semiconductor layer 111, a first-type semiconductor layer 112, an active layer 113, and a second-type semiconductor layer 114 are sequentially formed on the surface of the substrate 10 having the convex pattern structure T1 and the groove pattern structure T2, and a platform portion D1, a plurality of recessed portions D2, and a convex portion D3 are formed on the surface of the non-doped semiconductor layer 111 facing the substrate 10, the recessed portion D2 corresponds to the convex pattern structure T1, the convex portion D3 corresponds to the convex pattern structure T2, the convex portion D3 at least partially surrounds the plurality of recessed portions D2, and / or the convex portion D3 and the recessed portion D2 are alternately arranged;

[0099] S500: Reference Fig.20e As shown, the active layer 113 and the second-type semiconductor layer 114 are etched so that the active layer 113 and the second-type semiconductor layer 114 expose a portion of the first-type semiconductor layer 112 .

[0100] S600: Reference Fig.20e As shown, a first electrode M1 is formed on a surface of the first-type semiconductor layer 112 exposed to the active layer 113 and the second-type semiconductor layer 114 , and a second electrode M2 ​​is formed on a surface of the second-type semiconductor layer 114 away from the active layer 113 .

[0101] It can be understood that in the micro-LED 100 obtained by the above-mentioned preparation method, the raised portion D3 in the first surface S1 of the semiconductor stack 110 may include a surrounding portion D31, may include multiple micro-raised portions D32, or may include both the surrounding portion D31 and multiple micro-raised portions D32, depending on the specific circumstances.

[0102] Subsequent references Fig.18 As shown, the micro-LED 100 is transferred to the array substrate 200 from the second surface S2 side of the semiconductor stack 110 to form a micro-LED display panel.

[0103] Based on the same inventive concept, the present application also provides a display panel. Figure 3 , Figure 7 , Fig. 9 , Fig.11 , Fig.13 , Fig.14 , Fig.17 as well as Fig.13 , not only shows the cross-sectional structure of the micro-LED 100, but also shows a corresponding cross-sectional schematic diagram of the display panel including the micro-LED 100. With reference to these drawings, it can be seen that the display panel includes:

[0104] An array substrate 200;

[0105] A plurality of micro-LEDs 100 bonded to an array substrate 200, wherein the micro-LEDs 100 are the micro-LEDs provided by any of the above embodiments, and a first surface S1 of the micro-LEDs 100 is away from the array substrate 200 relative to a second surface S2 of the micro-LEDs 100;

[0106] The light shielding layer 300 is located on the array substrate 200 and between the micro LEDs 100 , and the height of the light shielding layer 300 relative to the array substrate 200 is smaller than the height of the first surface S1 of the micro LEDs 100 relative to the array substrate 200 .

[0107] It can be understood that after bonding multiple micro-LEDs 100 to the array substrate 200, black ink is printed between the micro-LEDs 100 through an inkjet printing process, and the black ink is leveled by the fluidity of the black ink to form a shading layer 300, thereby achieving the purpose of reducing reflection and fixing the micro-LEDs 100.

[0108] Since the first surface S1 of the micro-LED 100 is provided with a plurality of recessed portions D2, the first surface S1 is a roughened surface, thereby improving the light output efficiency and uniformity of the micro-LED; and, the first surface S1 of the micro-LED 100 is also provided with a raised portion D3, the raised portion D3 at least partially surrounds the plurality of recessed portions D2, and / or the raised portion D3 and the recessed portions D2 are arranged alternately, and the raised portion D3 can be used to reduce the black ink from climbing onto the first surface S1 of the micro-LED 100, thereby ensuring the normal light output of the micro-LED 100.

[0109] Furthermore, if Figure 3 , Figure 7 , Fig. 9 , Fig.11 , Fig.13 , Fig.14 as well as Fig.17 As shown, the display panel may further include:

[0110] An encapsulation glue layer 400 covering the micro LED 100 and the light shielding layer 300;

[0111] The packaging film / cover plate 500 is located on the side of the packaging glue layer away from the array substrate 200 .

[0112] It is understandable that the recessed portion D2 provided on the first surface S1 of the micro-LED 100 improves the light output efficiency and uniformity of the micro-LED by reflecting and refracting the emitted light, but it may cause a certain degree of glare. A material with a relatively high haze can be used as the packaging film / cover plate 500 to eliminate the glare effect.

[0113] Accordingly, an embodiment of the present application further provides a display device, Fig.21A schematic top view of a display device provided in an embodiment of the present application is shown. Fig.21 As shown, the display device 600 includes a display panel 700 provided by any of the above embodiments. Since the display panel 700 has been described in detail in the above embodiments, it will not be described again here.

[0114] The display device 600 can be any electronic device with a display function, such as a touch screen, a mobile phone, a tablet computer, a notebook computer, an e-reader, or a television.

[0115] The various parts in this manual are described in a combination of parallel and progressive ways. Each part focuses on the differences from other parts, and the same or similar parts between the various parts can be referenced to each other.

[0116] With respect to the above description of the disclosed embodiments, the features described in the embodiments in this specification may be replaced or combined with each other, so that professionals in the field can implement or use the present application. Various modifications to these embodiments will be apparent to professionals in the field, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A micro light emitting diode, characterized in that: include: A semiconductor stack, the semiconductor stack comprising a first surface and a second surface arranged opposite to each other, the first surface comprising a platform portion and a plurality of recessed portions recessed toward the second surface relative to the platform portion, the first surface further comprising a protruding portion protruding relative to the platform portion in a direction away from the second surface, the protruding portion at least partially surrounding the plurality of recessed portions, and / or the protruding portion and the recessed portions are arranged alternately.

2. The micro light emitting diode according to claim 1, characterized in that: The raised portion includes a surrounding portion that at least partially surrounds the plurality of recessed portions.

3. The micro light emitting diode according to claim 1, characterized in that: The protrusions include a plurality of micro-protrusions, the micro-protrusions are arranged along at least a portion of the peripheral area of ​​the plurality of recesses, and / or the micro-protrusions are arranged alternately with the recesses.

4. The micro light emitting diode according to claim 1, characterized in that: The raised portion includes a blocking portion and a plurality of micro-raised portions, the blocking portion at least partially surrounds the plurality of recessed portions, and the micro-raised portions are arranged alternately with the recessed portions.

5. The micro light emitting diode according to claim 2 or 4, characterized in that: The first surface includes four edges connected in sequence to form a rectangle, wherein the first edge and the third edge are arranged opposite to each other, the second edge and the fourth edge are arranged opposite to each other, and the length of the first edge is greater than the length of the second edge; The second edge and the fourth edge are provided with the blocking portion.

6. The micro light emitting diode according to claim 2 or 4, characterized in that: The enclosure portion is located around the plurality of recessed portions, and the enclosure portion surrounds the plurality of recessed portions.

7. The micro light emitting diode according to claim 2 or 4, characterized in that: The height h of the enclosure relative to the platform portion satisfies: 0 μm <h≤2μm。 8. The micro light emitting diode according to claim 3 or 4, characterized in that: The recessed portions are arranged in a row along a first direction, and a plurality of rows of recessed portions are arranged along a second direction, the first direction and the second direction intersect, and the first direction and the second direction are both parallel to the platform portion; The recessed portions in alternate rows overlap along the second direction, and the recessed portions in adjacent rows at least partially do not overlap along the second direction.

9. The micro light emitting diode according to claim 8, characterized in that: At least part of the micro-protrusions are arranged in a row along the first direction, and a plurality of rows of the micro-protrusions are arranged along the second direction; The micro-protrusions in alternate rows overlap along the second direction, and the micro-protrusions in adjacent rows at least partially do not overlap along the second direction.

10. The micro light emitting diode according to claim 3 or 4, characterized in that: The micro-protrusions are column-shaped or mushroom-shaped.

11. The micro light emitting diode according to claim 3 or 4, characterized in that: The orthographic projection area of ​​the micro-protrusion on the platform portion is smaller than the orthographic projection area of ​​the recessed portion on the platform portion.

12. The micro light emitting diode according to claim 4, characterized in that: A height of the blocking portion relative to the platform portion is greater than a height of the micro-protrusion portion relative to the platform portion.

13. The micro light emitting diode according to claim 1, characterized in that: The semiconductor stack comprises a non-doped semiconductor layer, a first-type semiconductor layer, an active layer and a second-type semiconductor layer stacked in sequence, wherein the active layer and the second-type semiconductor layer expose a portion of the first-type semiconductor layer; The surface of the non-doped semiconductor layer away from the first-type semiconductor layer is the first surface, the surface of the second-type semiconductor layer away from the active layer and the surface of the first-type semiconductor layer where the active layer and the second-type semiconductor layer are exposed are the second surface; A first electrode is disposed on a surface of the first-type semiconductor layer exposed by the active layer and the second-type semiconductor layer, and a second electrode is disposed on a surface of the second-type semiconductor layer facing away from the active layer.

14. A display panel, characterized in that: include: An array substrate; a plurality of micro-LEDs bonded to the array substrate, wherein the micro-LEDs are the micro-LEDs according to any one of claims 1 to 13, and a first surface of the micro-LEDs is away from the array substrate relative to a second surface of the micro-LEDs; A light shielding layer is located on the array substrate and between the micro-LEDs, wherein a height of the light shielding layer relative to the array substrate is smaller than a height of the first surface of the micro-LEDs relative to the array substrate.

15. The display panel according to claim 14, characterized in that: The display panel further includes: An encapsulation adhesive layer covering the micro light emitting diode and the light shielding layer; A packaging film or a cover plate is located on a side of the packaging adhesive layer away from the array substrate.

16. A display device, characterized in that: Comprising the display panel according to claim 14 or 15.

17. A method for preparing a micro light emitting diode, characterized in that: include: providing a substrate; Etching a surface of the substrate to form a plurality of raised pattern structures; Grooving the surface of the substrate having the convex pattern structure to form a groove pattern structure, wherein the groove pattern structure at least partially surrounds the plurality of convex pattern structures, and / or the groove pattern structure and the convex pattern structure are arranged alternately; A non-doped semiconductor layer, a first-type semiconductor layer, an active layer, and a second-type semiconductor layer are sequentially formed on the surface of the substrate having the convex pattern structure and the concave pattern structure, and a platform portion, a plurality of concave portions, and a convex portion are formed on the surface of the non-doped semiconductor layer facing the substrate, wherein the concave portion corresponds to the convex pattern structure, the convex portion corresponds to the convex pattern structure, the convex portion at least partially surrounds the plurality of concave portions, and / or the convex portion and the concave portion are alternately arranged; Etching the active layer and the second-type semiconductor layer so that the active layer and the second-type semiconductor layer expose a portion of the first-type semiconductor layer; A first electrode is formed on a surface of the first-type semiconductor layer where the active layer and the second-type semiconductor layer are exposed, and a second electrode is formed on a surface of the second-type semiconductor layer away from the active layer.

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