Miniature light-emitting structure and miniature light-emitting device

Abstract

The utility model relates to a miniature light-emitting structure and a miniature light-emitting device.The miniature light-emitting structure comprises a step structure and a first polarity electrode, and the step structure comprises a first semiconductor layer, a light-emitting layer and a second semiconductor layer which are sequentially arranged in a stacked mode and is provided with a light-emitting area and a peripheral electrode area; the first polarity electrode is arranged on the peripheral electrode area and surrounds the light-emitting layer; the first polarity electrode comprises a narrow visual angle part and a reflection part which are sequentially arranged in a stacked mode in the direction away from the first semiconductor layer, and the reflection part and the narrow visual angle part are configured to reflect and converge light emitted by the light-emitting layer respectively. The spacing distance between the orthographic projection of the reflection part on the plane where the first semiconductor layer is located and the orthographic projection of the light-emitting layer on the plane where the first semiconductor layer is located is larger than the spacing distance between the orthographic projection of the narrow visual angle part on the plane where the first semiconductor layer is located and the orthographic projection of the light-emitting layer on the plane where the first semiconductor layer is located. Therefore, the photoelectric property of the micro light-emitting diode chip with the horizontal structure can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor light emitting, in particular to a micro light emitting structure and a micro light emitting device. BACKGROUND

[0002] Micro-LED (Micro-Light Emitting Diode) display technology is a display technology that realizes the addressing control and individual driving of each pixel point by miniaturizing and arraying the traditional LED (Light Emitting Diode) structure and adopting CMOS (Complementary Metal Oxide Semiconductor) or TFT (Thin Film Transistor) to make a driving circuit.

[0003] However, the Micro-LED chip with a horizontal structure in the prior art has the problem of poor photoelectric performance. UTILITARIAN CONTENT

[0004] The present application provides a micro light emitting structure and a micro light emitting device to solve the problem of poor photoelectric performance of the Micro-LED chip with a horizontal structure in the prior art.

[0005] To solve the above problem, the present application provides a micro light emitting structure, which comprises a step structure and a first polarity electrode, the step structure comprises a first semiconductor layer, a light emitting layer and a second semiconductor layer which are sequentially stacked, the step structure comprises a light emitting area and a peripheral electrode area, the first polarity electrode is arranged on the peripheral electrode area, and the first polarity electrode surrounds the light emitting layer; and the first polarity electrode comprises a narrow viewing angle part and a reflection part which are sequentially stacked in a direction away from the first semiconductor layer, wherein the reflection part is configured to reflect the light emitted by the light emitting layer, the narrow viewing angle part is configured to converge the light emitted by the light emitting layer, and the interval distance between the orthographic projection of the reflection part on the plane where the first semiconductor layer is located and the orthographic projection of the light emitting layer on the plane where the first semiconductor layer is located is greater than the interval distance between the orthographic projection of the narrow viewing angle part on the plane where the first semiconductor layer is located and the orthographic projection of the light emitting layer on the plane where the first semiconductor layer is located.

[0006] Specifically, the narrow viewing angle part is configured to absorb the light emitted by the light emitting layer and propagating to the narrow viewing angle part.

[0007] Specifically, the material of the narrow viewing angle part comprises a light-absorbing conductive material.

[0008] Specifically, the material of the reflection part comprises a reflective conductive material.

[0009] The height of the first semiconductor layer in the peripheral electrode region in the stacking direction of the step structure is less than the height of the first semiconductor layer in the light emitting region in the stacking direction of the step structure, and the height of the narrow viewing angle part in the stacking direction of the step structure is less than the height of the first semiconductor layer in the light emitting region in the stacking direction of the step structure.

[0010] The orthographic projection of the reflecting part on the plane where the first semiconductor layer is located is located within the orthographic projection of the narrow viewing angle part on the plane where the first semiconductor layer is located.

[0011] The cross-sectional shape of the reflecting part parallel to the plane where the first semiconductor layer is located is annular, and the cross-sectional shape of the narrow viewing angle part parallel to the plane where the first semiconductor layer is located is annular.

[0012] The micro light emitting diode chip further comprises a current diffusion layer and a second polarity electrode, the current diffusion layer is arranged on the side of the second semiconductor layer away from the light emitting layer, the second polarity electrode is arranged on the side of the current diffusion layer away from the second semiconductor layer, and the surface of the first polarity electrode away from the first semiconductor layer and the surface of the second polarity electrode away from the first semiconductor layer are located in the same plane.

[0013] To solve the above problems, the embodiment of the present application further provides a micro light emitting device, which comprises the micro light emitting structure of any one of the above and a driving chip, and the driving chip is bonded with the micro light emitting structure.

[0014] The micro light emitting structure further comprises a first dielectric layer and a first conductive layer, the first dielectric layer covers the step structure and the first polarity electrode, the first conductive layer is arranged on the side of the first polarity electrode away from the first semiconductor layer, and the first conductive layer penetrates the first dielectric layer; the driving chip comprises a substrate, a driving circuit, a second dielectric layer and a second conductive layer, the driving circuit is arranged on one side of the substrate, the second dielectric layer and the second conductive layer are arranged on the side of the driving circuit away from the substrate, the second dielectric layer covers the driving circuit, the second conductive layer penetrates the second dielectric layer and is electrically connected with the driving circuit; and in the micro light emitting device, the first dielectric layer is bonded with the second dielectric layer, and the first conductive layer is bonded with the second conductive layer.

[0015] The beneficial effects of the present application are: the micro light emitting structure and the micro light emitting device provided by the present application, by arranging the first polarity electrode around the light emitting layer in the micro light emitting diode chip of horizontal structure, and the first polarity electrode includes a narrow viewing angle part and a reflection part arranged in layers, wherein the reflection part is configured to reflect the light emitted by the light emitting layer, the narrow viewing angle part is configured to converge part of the light emitted by the light emitting layer, and the lateral spacing distance between the reflection part and the light emitting layer is greater than the lateral spacing distance between the narrow viewing angle part and the light emitting layer, thereby ensuring that the current flowing laterally can flow to the lateral four around the light emitting layer during the use of the micro light emitting diode chip, so that the current diffusion between the P-type electrode and the N-type electrode is more uniform, thereby effectively solving the current crowding effect in the micro light emitting diode chip of horizontal structure in the prior art, reducing the damage risk of the light emitting stack, and improving the reliability of the micro light emitting diode chip, so that the electrical performance of the micro light emitting diode chip is improved.

[0016] And during the use of the micro light emitting diode chip, the reflection part can reflect the light emitted by the light emitting layer to the light emitting side to improve the light emitting efficiency of the micro light emitting diode chip; the narrow viewing angle part can block the large-angle light emitted by the light emitting layer to converge the light emitting angle of the micro light emitting diode chip, thereby reducing the light crosstalk problem between the pixels of the micro light emitting diode chip, so that the optical performance of the micro light emitting diode chip is improved. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0018] Figure 1 is a cross-sectional structure schematic diagram of the micro light emitting structure provided by the present application;

[0019] Figure 2 is Figure 1 is a top view structure schematic diagram of the first polarity electrode, the first semiconductor layer and the light emitting layer in

[0020] Figure 3 is another cross-sectional structure schematic diagram of the micro light emitting structure provided by the present application;

[0021] Figure 4 is a cross-sectional structure schematic diagram of the micro light emitting device provided by the present application;

[0022] Figure 5 is another cross-sectional structure schematic diagram of the micro light emitting device provided by the present application. DETAILED DESCRIPTION

[0023] The application examples are further described below in conjunction with the accompanying drawings and examples. It is particularly pointed out that the following examples are only for illustrating the application examples, but not for limiting the scope of the application examples. Similarly, the following examples are only some of the application examples, but not all of the application examples, and all other examples obtained by those skilled in the art without creative labor are within the scope of the application examples.

[0024] When describing the structure of a component, when a layer or a region is referred to as being "on" or "above" another layer or another region, it can mean that it is directly above the other layer or the other region, or other layers or regions are included therebetween. And if the component is flipped, the layer or the region will be "under" or "below" the other layer or the other region. In addition, the features, structures or characteristics described below can be combined in any suitable manner in one or more embodiments.

[0025] In addition, the directional terms mentioned in the application examples, such as [up], [down], [front], [back], [left], [right], [inward], [outward], [side] and the like, are only the directions of the attached drawings. Therefore, the directional terms used are used to illustrate and understand the application examples, but not to limit the application examples. In each figure, similar units are represented by the same reference numerals. For the sake of clarity, each part in the drawings is not drawn to scale. In addition, some related parts can not be shown in the drawings.

[0026] The following will be described in detail in conjunction with specific examples. It should be noted that the application examples can be presented in various forms, and some examples will be described below.

[0027] Please refer to Figure 1 and Figure 2 , Figure 1 is a schematic view of the cross-sectional structure of the micro light emitting structure provided by the application examples, Figure 2 is Figure 1 the top view structure schematic diagram of the first polar electrode, the first semiconductor layer and the light emitting layer in Figure 1 and Figure 2As shown, the micro light emitting structure 10 comprises a micro light emitting unit 100. Specifically, the micro light emitting unit 100 comprises a stepped structure 100A and a first polarity electrode 102, the stepped structure 100A comprises a first semiconductor layer 101, a light emitting layer 103 and a second semiconductor layer 104 which are sequentially stacked, and the stepped structure 100A has a light emitting area C1 and a peripheral electrode area C2, and the first polarity electrode 102 is arranged on the peripheral electrode area C2 and surrounds the light emitting layer 103.

[0028] Specifically, the stepped structure 100A can be a double-layer stepped structure, the light emitting area C1 can be an area where a top step surface F1 of the stepped structure 100A is located, and the peripheral electrode area C2 can be an area where a bottom step surface F2 of the stepped structure 100A is located.

[0029] The bottom step surface F2 of the stepped structure 100A is provided by an upper surface of the first semiconductor layer 101. The top step surface F1 of the stepped structure 100A is provided by an upper surface of the second semiconductor layer 104.

[0030] In the above-mentioned stepped structure 100A, the light emitting layer 103 can be a quantum well layer, such as an indium gallium nitride quantum well layer or an indium gallium nitride / gallium nitride multi-quantum well layer. The first semiconductor layer 101 and the second semiconductor layer 104 have different polarities. Specifically, the first semiconductor layer 101 can be one of an N-type semiconductor layer and a P-type semiconductor layer, and the second semiconductor layer 104 can be the other of the N-type semiconductor layer and the P-type semiconductor layer. The N-type semiconductor layer can be an N-type gallium nitride layer or an N-type gallium arsenide layer, and the P-type semiconductor layer can be a P-type gallium nitride layer or a P-type aluminum gallium nitride layer.

[0031] Correspondingly, the above-mentioned first polarity electrode 102 can be an N-type electrode electrically connected to the N-type semiconductor layer, or can be a P-type electrode electrically connected to the P-type semiconductor layer.

[0032] Specifically, as shown, the micro light emitting unit 100 can further comprise a second polarity electrode 105 arranged on a side of the second semiconductor layer 104 away from the light emitting layer 103. Figure 1

[0033] ​In some examples, the first semiconductor layer 101 and the second semiconductor layer 104 can be an N-type semiconductor layer and a P-type semiconductor layer, respectively, and correspondingly, the first polar electrode 102 and the second polar electrode 105 can be an N-type electrode and a P-type electrode, respectively. In other examples, the first semiconductor layer 101 and the second semiconductor layer 104 can be a P-type semiconductor layer and an N-type semiconductor layer, respectively, and correspondingly, the first polar electrode 102 and the second polar electrode 105 can be a P-type electrode and an N-type electrode, respectively.

[0034] It is understood that the micro-light-emitting unit 100 in this embodiment is a horizontally structured micro-light-emitting diode chip. Specifically, the P-type electrode and the N-type electrode in the micro-light-emitting unit 100 are located on the same side of the stepped structure 100A (i.e., Figure 1 The upper side of the stepped structure 100A), and the light emitted by the light-emitting layer 103 in the micro light-emitting unit 100 can come from the opposite side of the P-type electrode and the N-type electrode (i.e., Figure 1 The middle step structure 100A is injected from the lower side.

[0035] Furthermore, compared to existing horizontally structured micro-LED chips, where the lateral current flows only to one side of the light-emitting layer during use, resulting in poor current distribution uniformity and a tendency for current congestion, which can easily damage the light-emitting layer and affect the reliability of the micro-LED chip, this embodiment addresses this issue by designing the first polar electrode 102 as a ring structure surrounding the light-emitting layer 103. This ensures that the lateral current flows to all sides of the light-emitting layer 103 during use, resulting in more uniform current diffusion between the P-type and N-type electrodes. Therefore, this effectively solves the current congestion effect in existing horizontally structured micro-LED chips, reduces the risk of damage to the light-emitting layer, and improves the reliability of the horizontally structured micro-LED chip.

[0036] In this embodiment, as Figure 1 As shown, the first polar electrode 102 includes a narrow viewing angle portion 102A and a reflective portion 102B stacked sequentially in a direction away from the first semiconductor layer 101. The reflective portion 102B is configured to reflect the light emitted by the light-emitting layer 103, and the narrow viewing angle portion 102A is configured to converge part of the light emitted by the light-emitting layer 103.

[0037] Specifically, during the use of the micro-light-emitting unit 100, at least a portion of the light emitted by the light-emitting layer 103 that propagates to the reflective portion 102B can be reflected by the reflective portion 102B to the light-emitting side of the stepped structure 100A (i.e., Figure 1 The lower side of the stepped structure 100A can improve the light extraction efficiency and reduce the power consumption of the micro light-emitting unit 100.

[0038] In addition, compared with the prior art, in order to realize the reflection of the light emitted by the light-emitting layer, a reflective layer (such as a Bragg reflector) is made on the sidewall of the light-emitting stack. However, the sidewall reflective layer manufacturing process is too complex. In the embodiment, the first polarity electrode 102 is designed as a double-layer electrode structure surrounding the light-emitting layer 103, and the double-layer electrode structure has a light reflection function, which can effectively realize the reflection of the light emitted by the light-emitting layer 103, so that there is no need to additionally make a reflective layer on the sidewall of the light-emitting stack, that is, the sidewall reflective layer manufacturing process is saved, thereby reducing the production cost and better meeting the miniaturization requirement of the device.

[0039] In addition, it should be noted that the specific structure and material of the reflective part 102B are not limited in the embodiment, and the reflective part 102B can reflect at least part of the light emitted by the light-emitting layer 103 to the light-emitting side of the step structure 100A.

[0040] In the embodiment, the narrow viewing angle part 102A can specifically be configured to absorb or reflect the light emitted by the light-emitting layer 103 and propagating to the narrow viewing angle part 102A, so as to converge the light-emitting angle of the micro light-emitting unit 100. Specifically, during the use of the micro light-emitting unit 100, the narrow viewing angle part 102A can absorb or reflect the large-angle light emitted by the light-emitting layer 103, so as to converge the angle of the emitted light of the micro light-emitting unit 100, thereby reducing the light crosstalk problem between the pixels of the micro light-emitting unit 100, and improving the display effect of the micro light-emitting unit 100.

[0041] In addition, compared with the prior art, in order to realize the convergence of the light-emitting angle of the micro light-emitting diode chip, a microlens is made on the light-emitting side of the light-emitting stack. However, the microlens will cause the size of the micro light-emitting diode chip to increase. In the embodiment, the first polarity electrode 102 is designed as a double-layer electrode structure surrounding the light-emitting layer 103, and the double-layer electrode structure can block the large-angle light emitted by the light-emitting layer 103, so that the light-emitting angle of the micro light-emitting unit 100 is converged, thereby eliminating the need to additionally make a microlens on the light-emitting side of the light-emitting stack, that is, the microlens manufacturing process is saved, thereby reducing the production cost and better meeting the miniaturization requirement of the device.

[0042] In addition, it should be noted that the specific structure and material of the narrow viewing angle part 102A are not limited in the embodiment, and the narrow viewing angle part 102A can absorb or reflect the large-angle light emitted by the light-emitting layer 103.

[0043] Specifically, as shown in FIG. 1, the micro light-emitting unit 100 can further include a second polarity electrode 104, and the second polarity electrode 104 can be configured to be electrically connected to the first polarity electrode 102. Figure 1As shown, the distance between the orthographic projection of the reflective portion 102B onto the plane of the first semiconductor layer 101 and the orthographic projection of the light-emitting layer 103 onto the plane of the first semiconductor layer 101 can be greater than the distance between the orthographic projection of the narrow-viewing-angle portion 102B onto the plane of the first semiconductor layer 101 and the orthographic projection of the light-emitting layer 103 onto the plane of the first semiconductor layer 101. In other words, as Figure 2 As shown, when observing the first polar electrode 102, the first semiconductor layer 101, and the light-emitting layer 103 from a top-down perspective, it can be seen that the distance D1 between the reflective portion 102B of the first polar electrode 102 and the light-emitting layer 103 can be greater than the distance D2 between the narrow-viewing-angle portion 102B of the first polar electrode 102 and the light-emitting layer 103. This ensures that the orthographic projection of the narrow-viewing-angle portion 102B on the first surface F1 can completely or partially cover the space between the orthographic projection of the reflective portion 102B on the first surface F1 and the orthographic projection of the light-emitting layer 103 on the first surface F1. This allows the narrow-viewing-angle portion 102B to effectively absorb or reflect large-angle light emitted by the light-emitting layer 103, thereby achieving angular convergence of the emitted light from the micro-light-emitting unit 100.

[0044] Furthermore, in specific implementation, the specific value of the aforementioned interval distance D1 (i.e., the interval between the orthographic projection of the reflective portion 102B on the plane where the first semiconductor layer 101 is located and the orthographic projection of the light-emitting layer 103 on the plane where the first semiconductor layer 101 is located) can be determined according to the actual process conditions of the fabrication process of the reflective portion 102B, and should at least satisfy the following: during the fabrication process of the reflective portion 102B, the problem of leakage caused by the formation of conductive residues on the sidewall of the light-emitting layer 103 by the conductive material used to fabricate the reflective portion 102B can be effectively avoided.

[0045] Furthermore, the specific value of the aforementioned interval distance D2 (i.e., the interval between the orthographic projection of the narrow-viewing-angle portion 102A on the plane where the first semiconductor layer 101 is located and the orthographic projection of the light-emitting layer 103 on the plane where the first semiconductor layer 101 is located) can be determined according to actual needs based on the angular range of the light emitted by the light-emitting layer 103 selectively emitted by the narrow-viewing-angle portion 102B. The larger the interval distance D1, the larger the angular range of the light emitted by the light-emitting layer 103 selectively emitted by the narrow-viewing-angle portion 102B; the smaller the interval distance D1, the smaller the angular range of the light emitted by the light-emitting layer 103 selectively emitted by the narrow-viewing-angle portion 102B.

[0046] In this embodiment, as Figure 1 and Figure 2As shown, the reflective part 102B of the first polarity electrode 102 can be a ring structure, specifically, a cross-sectional shape of the reflective part 102B parallel to the plane where the first semiconductor layer 101 is located can be a ring shape, such as a circular ring shape or a square ring shape, etc. The narrow viewing angle part 102A of the first polarity electrode 102 can also be a ring structure, specifically, a cross-sectional shape of the narrow viewing angle part 102A parallel to the plane where the first semiconductor layer 101 is located can also be a ring shape, such as a circular ring shape or a square ring shape, etc. Moreover, the reflective part 102B and the narrow viewing angle part 102A of the first polarity electrode 102 are connected in the longitudinal direction Z.

[0047] Specifically, the center of the reflective part 102B in the first polarity electrode 102 can be aligned with the center of the light-emitting layer 103 in the stepped structure 100A in the longitudinal direction Z. The center of the narrow viewing angle part 102A in the first polarity electrode 102 can be aligned with the center of the light-emitting layer 103 in the stepped structure 100A in the longitudinal direction Z. In other words, as shown in FIG. 1B, the center of the reflective part 102B in the first polarity electrode 102 can be overlapped with the center of the light-emitting layer 103 in the stepped structure 100A in the top view, and the center of the narrow viewing angle part 102A in the first polarity electrode 102 can be overlapped with the center of the light-emitting layer 103 in the stepped structure 100A in the top view. Figure 2 As shown, when the first polarity electrode 102, the first semiconductor layer 101 and the light-emitting layer 103 are observed in the top view, the center of the reflective part 102B in the first polarity electrode 102 can be overlapped with the center of the light-emitting layer 103 in the stepped structure 100A, and the center of the narrow viewing angle part 102A in the first polarity electrode 102 can be overlapped with the center of the light-emitting layer 103 in the stepped structure 100A. In this way, it is beneficial to improve the intensity uniformity of light emitted by the micro light-emitting unit 100 at different angles.

[0048] In this embodiment, the material of the reflective part 102B in the first polarity electrode 102 can be the same as or different from the material of the narrow viewing angle part 102A.

[0049] Specifically, the material of the reflective part 102B in the first polarity electrode 102 includes a reflective material to ensure the light reflection function of the reflective part 102B. The material of the narrow viewing angle part 102A in the first polarity electrode 102 can include a light-absorbing material and / or a reflective material to ensure that the narrow viewing angle part 102A can absorb and / or reflect the light rays with a relatively large angle emitted by the light-emitting layer 103, thereby realizing selective emission of the light rays with a relatively small angle emitted by the light-emitting layer 103.

[0050] The reflective material can be any material with high reflectivity to visible light. In some examples, the reflective material can be specifically a conductive reflective material, such as titanium (Ti), aluminum (Al), silver (Ag), platinum (Pt), nickel (Ni), etc.

[0051] The light-absorbing material can be any material with high light absorption rate to visible light. In some examples, the light-absorbing material can be specifically a conductive light-absorbing material, such as graphene and other black or gray conductive materials.

[0052] In some examples, the material of the narrow viewing angle portion 102A in the first polar electrode 102 may include metals such as titanium (Ti), gold (Au), aluminum (Al), platinum (Pt), and nickel (Ni). The material of the reflective portion 102B in the first polar electrode 102 may include metals such as titanium (Ti), gold (Au), aluminum (Al), platinum (Pt), and nickel (Ni).

[0053] In some specific embodiments, the aforementioned narrow viewing angle portion 102A may be specifically configured to absorb light emitted by the light-emitting layer 103 that propagates to the narrow viewing angle portion 102A. Furthermore, the material of the aforementioned narrow viewing angle portion 102A may include a conductive light-absorbing material (e.g., graphene).

[0054] In other specific embodiments, the aforementioned narrow viewing angle portion 102A may be specifically configured to reflect light emitted by the light-emitting layer 103 that propagates to the narrow viewing angle portion 102A. Furthermore, the material of the aforementioned narrow viewing angle portion 102A may include a conductive reflective material (e.g., a metallic material such as titanium (Ti), aluminum (Al), silver (Ag), platinum (Pt), or nickel (Ni)).

[0055] In some embodiments, such as Figure 1 As shown, the orthographic projection of the reflective portion 102B in the first polar electrode 102 onto the plane of the first semiconductor layer 101 can lie within the orthographic projection of the narrow-viewing-angle portion 102A in the first polar electrode 102 onto the plane of the first semiconductor layer 101. This ensures that the reflective portion 102B and the narrow-viewing-angle portion 102A in the first polar electrode 102 can have a large contact area, thereby reducing the contact resistance of the reflective portion 102B and the narrow-viewing-angle portion 102A, and helping to improve the electrical performance of the micro-light-emitting unit 100.

[0056] In some embodiments, such as Figure 1 As shown, in the micro light-emitting unit 100, the surface of the first polar electrode 102 facing away from the first semiconductor layer 101 and the surface of the second polar electrode 105 facing away from the first semiconductor layer 101 can be located in the same plane to facilitate subsequent process steps.

[0057] In some embodiments, such as Figure 1 As shown, in the micro light-emitting unit 100, the first semiconductor layer 101 in the peripheral electrode region C2 is in the stacking direction of the stepped structure 100A (i.e., Figure 1 The height of the first semiconductor layer 101 in the light-emitting region C1 in the stacking direction of the step structure 100A is less than the height of the first semiconductor layer 101 in the light-emitting region C1 in the stacking direction of the step structure 100A, and the height of the narrow viewing angle portion 102A in the stacking direction of the step structure 100A is less than the height of the first semiconductor layer 101 in the light-emitting region C1 in the stacking direction of the step structure 100A.

[0058] Specifically, such asFigure 1 As shown, the lower surface of the first semiconductor layer 101 in the peripheral electrode region C2 and the lower surface of the first semiconductor layer 101 in the light-emitting region C1 can be located in the same plane. Furthermore, the height of the upper surface of the first semiconductor layer 101 in the peripheral electrode region C2 relative to the plane containing the lower surface of the first semiconductor layer 101 is less than the height of the upper surface of the first semiconductor layer 101 in the light-emitting region C1 relative to the plane containing the lower surface of the first semiconductor layer 101, and the height of the narrow viewing angle portion 102A relative to the plane containing the lower surface of the first semiconductor layer 101 is less than the height of the upper surface of the first semiconductor layer 101 in the light-emitting region C1 relative to the plane containing the lower surface of the first semiconductor layer 101. This prevents the conductive material in the narrow viewing angle portion 102A from migrating along the sidewall of the stepped structure 100A towards the light-emitting layer 103, thereby improving the reliability of the micro-light-emitting unit 100.

[0059] In some embodiments, such as Figure 1 As shown, the micro light-emitting unit 100 may further include a current diffusion layer 106, which is disposed between the second semiconductor layer 104 and the second polar electrode 105. Furthermore, the current diffusion layer 106 can distribute the current very uniformly throughout the entire second semiconductor layer 104 (e.g., a P-type gallium nitride layer), thereby effectively improving the luminous efficiency of the micro light-emitting unit 100.

[0060] In some examples, the current diffusion layer 106 described above can be fabricated by depositing multiple layers of metal (e.g., titanium (Ti), aluminum (Al), gold (Au), platinum (Pt) or nickel (Ni)) or semiconductor oxide (e.g., indium tin oxide (ITO) or zinc oxide (ZnO)) onto the surface of the second semiconductor layer 104 away from the light-emitting layer 103 to form a current conduction layer.

[0061] In some embodiments, such as Figure 1 As shown, the micro-light-emitting unit 100 may further include a first substrate 110, which supports the film structure located thereon. Specifically, the micro-light-emitting unit 100 may further include a buffer layer 111, which may be disposed on one side of the first substrate 110. The first semiconductor layer 101 may be disposed on the side of the buffer layer 111 facing away from the first substrate 110, and the first polar electrode 102 and the step structure 100A may be disposed on the side of the first semiconductor layer 101 facing away from the buffer layer 111. The buffer layer 111 can alleviate the stress caused by lattice mismatch and thermal expansion coefficient mismatch between the first semiconductor layer 101 and the first substrate 110.

[0062] In some examples, the first substrate 110 may be a sapphire substrate, a silicon substrate, or a silicon carbide substrate, etc. The material of the buffer layer 111 may include buffer materials such as silicon nitride, silicon oxide, gallium nitride, or aluminum nitride. For example, the buffer layer 111 may specifically be an unintentionally doped gallium nitride (U-GaN) layer.

[0063] In some embodiments, such as Figure 1 As shown, in the micro-light-emitting unit 100, the second polar electrode 105 can have a light-reflecting function, that is, it can reflect the light emitted by the light-emitting layer 103. Specifically, during the use of the micro-light-emitting unit 100, the light emitted by the light-emitting layer 103 that propagates to the second polar electrode 105 can be reflected by the second polar electrode 105, and the reflected light will propagate outward toward the side of the stepped structure 100A away from the second polar electrode 105 (i.e., the light-emitting side), thereby further improving the light-emitting efficiency of the micro-light-emitting unit 100.

[0064] Specifically, the second polar electrode 105 may include a reflective material, which can be any material with high reflectivity to visible light. In some examples, the reflective material may be a conductive reflective material, such as metals like titanium (Ti), aluminum (Al), silver (Ag), platinum (Pt), and nickel (Ni).

[0065] Furthermore, in specific implementations, the material of the second polar electrode 105 can be the same as the material of the reflective portion 102B in the first polar electrode 102; or, if the narrow viewing angle portion 102A in the first polar electrode 102 does not absorb light, the material of the second polar electrode 105 can also be the same as the material of the narrow viewing angle portion 102A in the first polar electrode 102.

[0066] In some embodiments, such as Figure 1 As shown, the micro light-emitting unit 100 may further include a first dielectric layer 107, which covers the stepped structure 100A, the first polar electrode 102, and the second polar electrode 105, and can fill the upper surface of the stepped structure 100A, making the surface of the first dielectric layer 107 facing away from the first semiconductor layer 101 a flat surface. Thus, the first dielectric layer 107 can effectively block external water and oxygen from eroding the stepped structure 100A, the first polar electrode 102, and the second polar electrode 105, thereby improving the reliability of the micro light-emitting unit 100.

[0067] Specifically, the material of the first dielectric layer 107 can include insulating materials such as silicon oxide, silicon nitride, and / or aluminum oxide. In some examples, the first dielectric layer 107 can be a single-layer structure, such as a silicon oxide layer. In other examples, the first dielectric layer 107 can also be a stacked-layer structure, such as a silicon nitride / silicon oxide stacked-layer structure, and the outermost layer of the stacked-layer structure away from the first semiconductor layer 101 can be a silicon oxide layer.

[0068] In some embodiments, as shown in FIG. 1A, the micro light emitting unit 100 can further include a first conductive layer 108A / 108B disposed on the side of the first polarity electrode 102 away from the first semiconductor layer 101 and on the side of the second polarity electrode 105 away from the second semiconductor layer 104, and the first conductive layer 108A / 108B penetrates the first dielectric layer 107. Figure 1

[0069] Specifically, the first conductive layer 108A / 108B can be provided in a plurality of numbers, and the plurality of first conductive layers 108A / 108B can include a first polarity conductive layer 108A and a second polarity conductive layer 108B. The first polarity conductive layer 108A can be disposed on the side of the first polarity electrode 102 away from the first semiconductor layer 101 within the peripheral electrode region C2 and electrically connected to the first polarity electrode 102. The second polarity conductive layer 108B can be disposed on the side of the second polarity electrode 105 away from the second semiconductor layer 104 and electrically connected to the second polarity electrode 105.

[0070] In some examples, the material of the first conductive layer 108A / 108B can include metals such as Cu (copper), Ag (silver), Au (gold), and Ni (nickel). Specifically, the material of the first conductive layer 108A / 108B can be copper.

[0071] In some embodiments, as shown in FIG. 1A, the micro light emitting unit 100 can further include a first conductive layer 108A / 108B disposed on the side of the first polarity electrode 102 away from the first semiconductor layer 101 and on the side of the second polarity electrode 105 away from the second semiconductor layer 104, and the first conductive layer 108A / 108B penetrates the first dielectric layer 107. Figure 1

[0072] ​​In some examples, the material of the barrier layer 109 may include conductive materials such as tantalum nitride (TaN) and / or titanium nitride (TiN).

[0073] In the above embodiments, the micro-light-emitting structure 10 may include one or more micro-light-emitting units 100. Each micro-light-emitting unit 100 may be a blue Micro-LED chip, a green Micro-LED chip, or a red Micro-LED chip, etc.

[0074] In some examples, such as Figure 1 As shown, the aforementioned micro-light-emitting structure 10 may include a micro-light-emitting unit 100, for example, it may specifically be a micro-light-emitting unit 100.

[0075] In other examples, such as Figure 3 As shown, the micro-light-emitting structure 10 may include a plurality of micro-light-emitting units 100, which may be arranged in an array, and the first substrate 110 of the plurality of micro-light-emitting units 100 may be connected into an integral structure, and the stepped structures 100A of the plurality of micro-light-emitting units 100 may be arranged at intervals.

[0076] As can be seen from the above, the micro-light-emitting structure provided in this application embodiment, by arranging a first polar electrode around the light-emitting layer in a horizontally structured micro-light-emitting diode chip, and the first polar electrode including a narrow viewing angle portion and a reflective portion stacked together, wherein the reflective portion is configured to reflect the light emitted by the light-emitting layer, the narrow viewing angle portion is configured to converge the light emitted by the light-emitting layer, and the lateral spacing between the reflective portion and the light-emitting layer is greater than the lateral spacing between the narrow viewing angle portion and the light-emitting layer, thereby ensuring that the laterally flowing current can flow to the lateral periphery of the light-emitting layer during the use of the micro-light-emitting diode chip, making the current diffusion between the P-type electrode and the N-type electrode more uniform, thus effectively solving the current congestion effect in the horizontally structured micro-light-emitting diode chip in the prior art, reducing the risk of damage to the light-emitting stack, and improving the reliability of the micro-light-emitting diode chip, thus improving the electrical performance of the horizontally structured micro-light-emitting diode chip. Furthermore, during the use of the micro LED chip, the reflective part can reflect the light emitted by the light-emitting layer to the light-emitting side, thereby improving the light emission efficiency of the micro LED chip; the narrow viewing angle part can block the large-angle light emitted by the light-emitting layer from being emitted, so as to converge the light emission angle of the micro LED chip, thereby reducing the optical crosstalk problem between pixels of the micro LED chip, thus improving the optical performance of the horizontal structure micro LED chip.

[0077] Please see Figure 4 , Figure 4 This is a schematic cross-sectional view of the micro light-emitting device provided in an embodiment of this application.Figure 4 As shown, the micro light-emitting device 1 includes the micro light-emitting structure 10 of any of the above embodiments (such as...). Figures 1 to 3 As shown in the figure, the micro light-emitting structure 10 is bonded to the driver chip 200, thereby enabling the driver chip 200 to drive the micro light-emitting structure 10 to emit light, so as to realize the display function of the micro light-emitting device 1.

[0078] Specifically, such as Figure 4 As shown, the driving chip 200 may include a second substrate 201, a driving circuit 202, a second dielectric layer 203, and a second conductive layer 204. The driving circuit 202 is disposed on one side of the second substrate 201, the second dielectric layer 203 and the second conductive layer 204 are disposed on the side of the driving circuit 202 opposite to the second substrate 201, and the second dielectric layer 203 covers the driving circuit 202. The second conductive layer 204 penetrates the second dielectric layer 203 and is electrically connected to the driving circuit 202.

[0079] Furthermore, in the aforementioned micro-light-emitting device 1, the second dielectric layer 203 of the driving chip 200 can be bonded to the first dielectric layer 107 of the micro-light-emitting unit 100, and the second conductive layer 204 of the driving chip 200 can be bonded to the first conductive layers 108A / 108B of the micro-light-emitting unit 100, thereby realizing the bonding connection between the driving chip 200 and the corresponding micro-light-emitting unit 100.

[0080] Specifically, such as Figure 4 As shown, the number of second conductive layers 204 included in the aforementioned driving chip 200 can be multiple, and these multiple second conductive layers 204 can correspond one-to-one with the multiple first conductive layers 108A / 108B included in the corresponding micro light-emitting unit 100. Furthermore, in the micro light-emitting device 1, each second conductive layer 204 in the driving chip 200 can be correspondingly bonded to each first conductive layer 108A / 108B in the micro light-emitting unit 100. The second conductive layer 204 correspondingly bonded to the first polar conductive layer 108A can be the common electrode (or cathode) of the driving chip 200, and the second conductive layer 204 correspondingly bonded to the second polar conductive layer 108B can be the pixel electrode (or anode) of the driving chip 300A.

[0081] In some examples, the material of the second conductive layer 204 may include metals such as Cu (copper), Ag (silver), Au (gold), and Ni (nickel). Furthermore, in specific implementations, the material of the second conductive layer 204 may be the same as the material of the first conductive layers 108A / 108B; for example, both may be copper.

[0082] In some embodiments, such as Figure 5As shown, the micro light emitting structure 10 can include a plurality of micro light emitting units 100, which can be arranged in an array, and the first substrates 110 of the plurality of micro light emitting units 100 can be connected as an integral structure, and the step structures 100A of the plurality of micro light emitting units 100 can be arranged at intervals. The number of the driving chips 200 included in the micro light emitting device 1 can also correspond to a plurality. In the micro light emitting device 1, each driving chip 200 can be bonded to the corresponding micro light emitting unit 100.

[0083] Specifically, the number of the driving chips 200 included in the micro light emitting device 1 can be equal to the number of the micro light emitting units 100 included in the micro light emitting structure 10, and in the micro light emitting device 1, the driving chips 200 can correspond to the micro light emitting units 100 one by one.

[0084] In addition, in the embodiment in which the number of the driving chips 200 included in the micro light emitting device 1 is a plurality, as shown, Figure 5 the second substrates 201 of all the driving chips 200 included in the micro light emitting device 1 can be connected as an integral structure.

[0085] In the present embodiment, the micro light emitting device 1 can not only be applied to the projection part of the electronic device such as optical projection, vehicle head-up display (HUD), etc., but also be applied to the display part of the electronic device, for example, the electronic device can include: a smart phone, a smart watch, a notebook computer, a tablet computer, a driving recorder, a navigator, a head-mounted device, etc. Any device with a display screen, and can also be applied to the lighting part of the electronic device, for example, the electronic device can include: a vehicle, a street lamp, etc. Any device with a lighting component.

[0086] It should be noted that the micro light emitting device provided in the present embodiment can realize the beneficial effects of any one of the micro light emitting devices provided in the present embodiment due to the provision of the micro light emitting structure provided in the present embodiment. Details are described in the foregoing embodiments, which will not be repeated here.

[0087] The above only describes the preferred embodiments of the present application and should not be used to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A micro light emitting structure, characterized by, The micro light emitting structure comprises a step structure and a first polarity electrode, the step structure comprises a first semiconductor layer, a light emitting layer and a second semiconductor layer which are sequentially stacked, the step structure comprises a light emitting area and a peripheral electrode area, the first polarity electrode is arranged on the peripheral electrode area, and the first polarity electrode surrounds the light emitting layer; The first polarity electrode comprises a narrow viewing angle part and a reflection part which are sequentially stacked in a direction away from the first semiconductor layer, the reflection part is configured to reflect light emitted by the light emitting layer, the narrow viewing angle part is configured to converge light emitted by the light emitting layer, and a distance between a projection of the reflection part on a plane where the first semiconductor layer is located and a projection of the light emitting layer on the plane where the first semiconductor layer is located is greater than a distance between a projection of the narrow viewing angle part on the plane where the first semiconductor layer is located and the projection of the light emitting layer on the plane where the first semiconductor layer is located.

2. The micro light emitting structure of claim 1, wherein, The narrow viewing angle part is specifically configured to absorb light emitted by the light emitting layer and propagating to the narrow viewing angle part.

3. The micro light emitting structure of claim 2, wherein, The material of the narrow viewing angle part comprises a light-absorbing conductive material.

4. The micro light emitting structure of claim 1, wherein, The material of the reflection part comprises a reflective conductive material.

5. The micro light emitting structure of claim 1, wherein, A height of the first semiconductor layer in the step structure in a stacking direction of the step structure in the peripheral electrode area is less than a height of the first semiconductor layer in the step structure in the stacking direction of the step structure in the light emitting area, and a height of the narrow viewing angle part in the step structure is less than the height of the first semiconductor layer in the step structure in the stacking direction of the step structure in the light emitting area.

6. The micro light emitting structure of claim 1, wherein, The projection of the reflection part on the plane where the first semiconductor layer is located is located in the projection of the narrow viewing angle part on the plane where the first semiconductor layer is located.

7. The micro light emitting structure of claim 1, wherein, The cross-sectional shape of the reflection part parallel to the plane where the first semiconductor layer is located is annular, and the cross-sectional shape of the narrow viewing angle part parallel to the plane where the first semiconductor layer is located is annular.

8. The micro light emitting structure of claim 1, wherein, The micro light emitting structure further comprises a current diffusion layer and a second polarity electrode, the current diffusion layer is arranged on a side of the second semiconductor layer away from the light emitting layer, the second polarity electrode is arranged on a side of the current diffusion layer away from the second semiconductor layer, and a surface of the first polarity electrode away from the first semiconductor layer and a surface of the second polarity electrode away from the first semiconductor layer are located in the same plane.

9. A miniature light-emitting device, characterized in that, The micro light emitting structure comprises a step structure and a first polarity electrode, the step structure comprises a first semiconductor layer, a light emitting layer and a second semiconductor layer which are sequentially stacked, the step structure comprises a light emitting area and a peripheral electrode area, the first polarity electrode is arranged on the peripheral electrode area, and the first polarity electrode surrounds the light emitting layer; 10. The micro light emitting device of claim 9, wherein, The micro light emitting structure further comprises a first dielectric layer and a first conductive layer, the first dielectric layer covers the step structure and the first polarity electrode, the first conductive layer is arranged on a side of the first polarity electrode away from the first semiconductor layer, and the first conductive layer penetrates the first dielectric layer; The driving chip comprises a substrate, a driving circuit, a second dielectric layer and a second conductive layer, wherein the driving circuit is arranged on one side of the substrate, the second dielectric layer and the second conductive layer are arranged on the side of the driving circuit away from the substrate, the second dielectric layer covers the driving circuit, and the second conductive layer penetrates through the second dielectric layer and is electrically connected with the driving circuit. In the micro light emitting device, the first dielectric layer is bonded with the second dielectric layer, and the first conductive layer is bonded with the second conductive layer.

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