Light-emitting substrate, preparation method thereof and display device

Abstract

The invention provides a light-emitting substrate, a preparation method thereof and a display device. The light-emitting substrate comprises a substrate body and a plurality of light-emitting chips arranged on the substrate body. The light-emitting chip comprises a first electrode and light-emitting bodies located on the side, away from the substrate, of the first electrode, and the multiple light-emitting bodies are arranged in an array mode in the first direction and the second direction. The light-emitting main body comprises a first semiconductor layer, a light-emitting layer and a second semiconductor layer which are sequentially arranged far away from the substrate, and the second semiconductor layer comprises a first bottom surface facing the substrate, a first top surface deviating from the substrate and a first side surface connected between the first bottom surface and the first top surface; the light-emitting chip further comprises a second electrode, and the spacing distance between the surface, close to the substrate, of the second electrode and the first surface of the substrate is larger than the spacing distance between the first bottom face and the first surface of the substrate. The first side surfaces of at least a part of the second semiconductor layers in the plurality of light-emitting chips are electrically connected through a second electrode.

Description

Technical Field

[0001] This disclosure relates to the field of display technology, and in particular to a light-emitting substrate, a method for preparing the substrate, and a display device thereof. Background Technology

[0002] Micro light-emitting diodes (Micro LEDs) typically refer to LED devices whose chip size has been reduced to within 100 micrometers. By arranging red, green, and blue Micro LEDs according to a specific rule on a thin-film transistor (TFT) or complementary metal-oxide-semiconductor (CMOS), a miniature device capable of full-color display is formed. These miniature devices offer advantages such as independent light emission control, high brightness, low power consumption, ultra-high resolution, and high color saturation. They can also achieve flexible and transparent displays. Furthermore, because Micro LEDs use inorganic materials and have a simple structure, they exhibit excellent lifespan and reliability, making them a promising next-generation core product in the display field.

[0003] In related technologies, the general process involves bonding the LED epitaxial layer as a whole to the CMOS driver backplane, followed by LED mesa etching, sidewall protection, and full-surface fabrication of transparent electrodes. This method involves many process steps and there is optical crosstalk between adjacent pixels.

[0004] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] In one aspect, a light-emitting substrate is provided, comprising a substrate and a plurality of light-emitting chips disposed on the substrate;

[0006] The light-emitting chip includes: a first electrode and a light-emitting body located on the side of the first electrode away from the substrate, and a plurality of light-emitting bodies are arranged in an array in a first direction and a second direction;

[0007] The light-emitting body includes: a first semiconductor layer located on the side of the first electrode away from the substrate; a light-emitting layer located on the side of the first semiconductor layer away from the substrate; and a second semiconductor layer located on the side of the light-emitting layer away from the substrate, the second semiconductor layer including a first bottom surface facing the substrate, a first top surface away from the substrate, and a first side surface connected between the first bottom surface and the first top surface;

[0008] The light-emitting chip further includes a second electrode, wherein the distance between the surface of the second electrode near the substrate and the first surface of the substrate is greater than the distance between the first bottom surface and the first surface of the substrate; and

[0009] The first side of the second semiconductor layer of at least a portion of the plurality of light-emitting chips is electrically connected via the second electrode.

[0010] According to some exemplary embodiments, the first electrode and the second electrode are made of the same material; and / or, the thickness of the first electrode in a third direction is substantially equal to the thickness of the second electrode in the third direction, the third direction being parallel to the light emission direction of the light-emitting substrate.

[0011] According to some exemplary embodiments, the orthographic projection of the second electrode on the substrate falls into the gap between the orthographic projections of the plurality of light-emitting bodies on the substrate.

[0012] According to some exemplary embodiments, the shape of the orthographic projection of the second electrode onto the substrate is a grid-like structure.

[0013] According to some exemplary embodiments, the second electrode includes a second top surface facing away from the substrate, the second top surface and the first top surface forming a planarized surface, that is, the distance between the second top surface and the first surface of the substrate is substantially equal to the distance between the first top surface and the first surface of the substrate.

[0014] According to some exemplary embodiments, the second semiconductor layer has a first thickness in a third direction, the second electrode has a second thickness in the third direction, the first thickness is greater than the second thickness, and the third direction is parallel to the light emission direction of the light-emitting substrate.

[0015] According to some exemplary embodiments, the first thickness is in the range of 3 micrometers to 4 micrometers; and / or,

[0016] The second thickness is less than 1 micrometer.

[0017] According to some exemplary embodiments, the material of the second electrode includes an opaque conductive material.

[0018] According to some exemplary embodiments, the first semiconductor layer includes a body portion and a passivation portion, the body portion and the passivation portion being disposed adjacent to each other; and the passivation portion surrounding the body portion.

[0019] According to some exemplary embodiments, the ratio of the resistance of the passivation portion to the resistance of the main body portion is greater than 2.6; and / or,

[0020] The width of the main body portion in the first direction is greater than the width of the passivation portion in the first direction; and / or,

[0021] The width of the main body portion in the second direction is greater than the width of the passivation portion in the second direction.

[0022] According to some exemplary embodiments, the orthographic projection of the first semiconductor layer on the substrate completely overlaps with the orthographic projection of the light-emitting layer on the substrate; and / or,

[0023] The orthogonal projection of the light-emitting layer on the substrate completely overlaps with the orthogonal projection of the second semiconductor layer on the substrate.

[0024] According to some exemplary embodiments, the light-emitting substrate further includes a filling layer, the filling layer including at least one filling portion located between two adjacent light-emitting chips;

[0025] The filling portion includes: a first portion located between two adjacent light-emitting bodies; and a second portion located between two adjacent first electrodes.

[0026] Wherein, the width of the first portion in the first direction is smaller than the width of the second portion in the first direction; and

[0027] The width of the first part in the second direction is smaller than the width of the second part in the second direction.

[0028] According to some exemplary embodiments, the light-emitting substrate further includes a driving circuit layer located between the substrate and the light-emitting chip; and

[0029] At least a portion of the plurality of first electrodes in the plurality of light-emitting chips are bonded to the driving circuit layer.

[0030] According to some exemplary embodiments, the light-emitting substrate further includes a third electrode located on the side of the second electrode away from the substrate, the third electrode being electrically connected to the second electrode; and

[0031] The third electrode is electrically connected to at least a portion of the plurality of second semiconductor layers.

[0032] According to some exemplary embodiments, the third electrode is a full-surface electrode; and

[0033] The material of the third electrode includes a transparent conductive material.

[0034] According to some exemplary embodiments, the light-emitting substrate further includes a color conversion layer located on the side of the second semiconductor layer away from the substrate. The color conversion layer includes a plurality of first color conversion sections arranged in an array, the first color conversion sections being configured to generate light of a first wavelength when excited by light emitted by the light-emitting body.

[0035] In this configuration, a plurality of first color conversion units are arranged in a one-to-one correspondence with a portion of a plurality of light-emitting bodies, and the orthographic projection of the light-emitting body on the substrate falls within the orthographic projection of the corresponding first color conversion unit on the substrate.

[0036] According to some exemplary embodiments, the color conversion layer further includes a plurality of second color conversion units arranged in an array, the second color conversion units being configured to generate light of a second wavelength when excited by light emitted by the light-emitting body, the second wavelength being smaller than the first wavelength.

[0037] In this configuration, a plurality of second color conversion units are arranged in a one-to-one correspondence with a portion of a plurality of light-emitting bodies, and the orthogonal projection of the light-emitting body on the substrate falls within the orthogonal projection of the corresponding second color conversion unit on the substrate.

[0038] According to some exemplary embodiments, the color conversion layer further includes a plurality of first scattering portions arranged in an array, the first scattering portions being configured such that the wavelength of light passing through the first scattering portions remains substantially unchanged.

[0039] In this configuration, a plurality of the first scattering portions are arranged in a one-to-one correspondence with a portion of the plurality of light-emitting bodies, and the orthogonal projection of the light-emitting body on the substrate falls within the orthogonal projection of the corresponding first scattering portion on the substrate.

[0040] According to some exemplary embodiments, the light-emitting body is configured to emit light of a third wavelength, which is smaller than both the second wavelength and the first wavelength.

[0041] According to some exemplary embodiments, a plurality of first color conversion units, a plurality of second color conversion units, and a plurality of first scattering units are all spaced apart; and

[0042] The color conversion layer further includes a plurality of isolation pillars disposed in the gap between any two of the first color conversion section, the second color conversion section and the first scattering section, wherein the orthographic projection of the isolation pillars on the substrate at least partially overlaps with the orthographic projection of the second electrode on the substrate.

[0043] According to some exemplary embodiments, at least one of the first color conversion section, the second color conversion section, and the first scattering section is in the shape of an inverted trapezoid; and / or,

[0044] At least one of the isolation columns is trapezoidal in shape.

[0045] According to some exemplary embodiments, the light-emitting chip includes a Micro-LED light-emitting chip; and / or,

[0046] The light-emitting layer includes a multi-quantum-well layer; and / or,

[0047] The first color conversion unit includes red quantum dots; and / or,

[0048] The second color conversion unit includes green quantum dots;

[0049] The first scattering part includes multiple scattering particles.

[0050] In another aspect, a display device is provided, wherein the display device includes a light-emitting substrate as described in any of the preceding claims.

[0051] In another aspect, a method for preparing a light-emitting substrate is provided, wherein the method includes:

[0052] Provide temporary substrate;

[0053] A second semiconductor material layer, a light-emitting material layer, and a first semiconductor material layer are sequentially stacked on the temporary substrate.

[0054] Multiple passivation portions are formed in an array in multiple regions of the first semiconductor material layer using patterning and ion implantation processes.

[0055] A patterning process is performed on the first semiconductor material layer, the light-emitting material layer, and the second semiconductor material layer to form a plurality of light-emitting bodies arranged in an array, wherein the light-emitting body includes a second semiconductor layer, a light-emitting layer, and a first semiconductor layer that are sequentially moved away from the temporary substrate; and the first semiconductor layer includes a body portion and a passivation portion, wherein the passivation portion surrounds the body portion;

[0056] An electrode material layer is formed on the side of the first semiconductor layer away from the temporary substrate, and a patterning process is performed to form a first electrode and a second electrode, wherein a plurality of first sides of the second semiconductor layer are electrically connected through the second electrode.

[0057] A filling material layer is formed in the gap between the light-emitting body and the gap between the first electrode, and a patterning process is performed to form the filling layer;

[0058] Remove the temporary substrate to form an epitaxial layer containing multiple light-emitting chips;

[0059] A driving backplane is provided, the driving backplane including a substrate and a driving circuit layer; and

[0060] The plurality of first electrodes in the epitaxial layer are bonded to the driving circuit layer to form the light-emitting substrate.

[0061] According to some exemplary embodiments, after obtaining the epitaxial layer containing multiple light-emitting chips and before providing the driving backplane, the method further includes:

[0062] The epitaxial layer is transferred onto a first substrate, wherein a first surface of the epitaxial layer near the first electrode is disposed on the first substrate;

[0063] An isolation pillar material layer is deposited on the second surface of the epitaxial layer, and a patterning process is performed on the isolation pillar material layer to form a plurality of isolation pillars arranged in a grid, wherein the second surface is the surface of the epitaxial layer near the second electrode;

[0064] A color conversion material layer is filled into the gaps of the isolation pillars using printing technology to form a color conversion layer, the color conversion layer including a plurality of first color conversion parts, a plurality of second color conversion parts, and a plurality of first scattering parts;

[0065] An encapsulation layer is formed on the side of the color conversion layer away from the first substrate; and

[0066] Remove the first substrate. Attached Figure Description

[0067] The foregoing contents, as well as other objects, features, and advantages of this disclosure, will become clearer from the following description of embodiments with reference to the accompanying drawings, in which:

[0068] Figure 1 This is a plan view of a light-emitting substrate according to an embodiment of the present disclosure;

[0069] Figure 2 It is along Figure 1 A schematic diagram of the cross-section taken by the centerline AA';

[0070] Figure 3 This is a partial cross-sectional schematic diagram of a light-emitting substrate according to an embodiment of the present disclosure;

[0071] Figure 4 This is a partial cross-sectional schematic diagram of a light-emitting substrate according to an embodiment of the present disclosure;

[0072] Figure 5 This is a projection relationship diagram of the main body portion and the passivation portion in the first semiconductor layer according to an embodiment of the present disclosure;

[0073] Figure 6A and Figure 6B This is a partial cross-sectional schematic diagram of a light-emitting substrate according to an embodiment of the present disclosure;

[0074] Figure 7 A partial cross-sectional schematic diagram of a light-emitting substrate according to an embodiment of the present disclosure;

[0075] Figure 8 A partial cross-sectional schematic diagram of a light-emitting substrate according to an embodiment of the present disclosure;

[0076] Figure 9 This is a flowchart illustrating the fabrication process of a light-emitting substrate according to an embodiment of the present disclosure;

[0077] Figures 10A-10H These are schematic cross-sectional views of some film layers during the fabrication process of the light-emitting substrate according to embodiments of the present disclosure;

[0078] Figure 11 This is a partial fabrication flowchart of a light-emitting substrate according to an embodiment of the present disclosure;

[0079] Figures 12A-12E These are cross-sectional schematic diagrams of a portion of the film layers during the fabrication process of the light-emitting substrate according to embodiments of the present disclosure; and

[0080] Figure 13 This is a structural block diagram of a display device according to an embodiment of the present disclosure.

[0081] It should be noted that, for clarity, the dimensions of layers, structures, or regions in the accompanying drawings used to describe embodiments of the present invention may be enlarged or reduced; that is, these drawings are not drawn to actual scale. Detailed Implementation

[0082] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0083] It should be noted that, for clarity and / or descriptive purposes, the dimensions and relative dimensions of components may be enlarged in the accompanying drawings. Therefore, the dimensions and relative dimensions of the individual components are not necessarily limited to those shown in the drawings. In the specification and accompanying drawings, the same or similar reference numerals indicate the same or similar parts.

[0084] Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art. The terms “first,” “second,” and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as “comprising” or “including” mean that an element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects.

[0085] In this document, unless otherwise specified, directional terms such as "up," "down," "left," "right," "inner," and "outer" are used to indicate orientation or positional relationships based on the accompanying drawings, and are used only for the convenience of describing this disclosure, and are not intended to indicate or imply that the device, element, or component referred to must have a specific orientation, or be constructed or operated in a specific orientation. It should be understood that when the absolute position of the described object changes, the relative positional relationships they represent may also change accordingly. Therefore, these directional terms should not be construed as limitations on this disclosure.

[0086] In this document, unless otherwise stated, the term "electrical connection" can mean that two components or elements are directly electrically connected, for example, component or element A is in direct contact with component or element B, and an electrical signal can be transmitted between them; it can also mean that two components or elements are electrically connected through a conductive medium, such as a conductive wire, for example, component or element A is electrically connected to component or element B through a conductive wire to transmit an electrical signal between the two components or elements; it can also mean that two components or elements are electrically connected through at least one electronic component, for example, component or element A is electrically connected to component or element B through at least one thin-film transistor to transmit an electrical signal between the two components or elements.

[0087] In this article, "parallel" refers to the state where the angle formed by two straight lines or two planes is greater than -10° and less than 10°, and therefore also includes the state where the angle is greater than -5° and less than 5°. In addition, "perpendicular" refers to the state where the angle formed by two straight lines or two planes is greater than 80° and less than 100°, and therefore also includes the state where the angle is greater than 85° and less than 95°.

[0088] In this disclosure, “about” means a value that is not strictly limited and allows for process and measurement errors.

[0089] This disclosure provides a light-emitting substrate. Specifically, the light-emitting substrate includes a substrate and a plurality of light-emitting chips disposed on the substrate. Each light-emitting chip includes a first electrode and a light-emitting body located on the side of the first electrode away from the substrate, with the plurality of light-emitting bodies arranged in an array in a first direction and a second direction. Each light-emitting body includes a first semiconductor layer located on the side of the first electrode away from the substrate; a light-emitting layer located on the side of the first semiconductor layer away from the substrate; and a second semiconductor layer located on the side of the light-emitting layer away from the substrate. The second semiconductor layer includes a first bottom surface facing the substrate, a first top surface facing away from the substrate, and a first side surface connecting the first bottom surface and the first top surface. The light-emitting chip also includes a second electrode, wherein the distance between the surface of the second electrode near the substrate and the first surface of the substrate is greater than the distance between the first bottom surface and the first surface of the substrate. At least a portion of the first side surface of the second semiconductor layer in the plurality of light-emitting chips is electrically connected via the second electrode.

[0090] With this design, the sidewalls (e.g., the first side) of multiple light-emitting chips can share a second electrode (e.g., the second electrode is an N-electrode). The second electrode can simultaneously serve as an electrode connection and a light shield, which helps reduce optical crosstalk between adjacent LED pixels. Moreover, the first electrode (e.g., the first electrode is a P-electrode) and the second electrode can be formed in one step, which simplifies the manufacturing process and reduces costs.

[0091] Figure 1 This is a plan view of a light-emitting substrate according to an embodiment of the present disclosure. Figure 2 It is along Figure 1 A schematic diagram of the cross-section taken by the midline AA'.

[0092] Exemplarily, in embodiments of this disclosure, reference is made to Figure 1 and Figure 2 The light-emitting substrate 100 may include a substrate 1 and a plurality of light-emitting chips 2 disposed on the substrate 1.

[0093] For example, the light-emitting chip 2 may include a Micro LED light-emitting chip. For instance, the light-emitting chip 2 may include one or more combinations of red Micro LED light-emitting chips, green Micro LED light-emitting chips, and blue Micro LED light-emitting chips.

[0094] In some embodiments, the light-emitting substrate 100 can be used in a backlight module to provide backlight for a liquid crystal display panel. Alternatively, the light-emitting substrate 100 can also be used in a self-emissive display panel. When the light-emitting substrate 100 is used in a display device, color display can be achieved by utilizing light-emitting chips 2 that emit light of different colors.

[0095] For example, the light-emitting chip 2 includes a first electrode 21 and a light-emitting body 22 located on the side of the first electrode 21 away from the substrate 1. A plurality of light-emitting bodies 22 are arranged in an array in a first direction X and a second direction Y.

[0096] For example, the light-emitting body 22 may include: a first semiconductor layer 221 located on the side of the first electrode 21 away from the substrate 1; a light-emitting layer 222 located on the side of the first semiconductor layer 221 away from the substrate 1; and a second semiconductor layer 223 located on the side of the light-emitting layer 222 away from the substrate 1.

[0097] Exemplarily, one of the first semiconductor layer 221 and the second semiconductor layer 223 is an N-type semiconductor layer, and the other is a P-type semiconductor layer. For example, the first semiconductor layer 221 is a P-type semiconductor layer, and the second semiconductor layer 223 is an N-type semiconductor layer. Alternatively, the first semiconductor layer 221 is an N-type semiconductor layer, and the second semiconductor layer 223 is a P-type semiconductor layer. Exemplarily, the N-type semiconductor layer may include n-type GaN, and the P-type semiconductor layer may include p-type GaN. In some embodiments, the P-type semiconductor layer may be a single-layer structure, and in other embodiments, the P-type semiconductor layer may be a multi-layer structure.

[0098] For example, the light-emitting layer 222 may include a multi-quantum well layer. For instance, the light-emitting layer 222 may include multiple quantum well layers for generating various colors of light. For example, the light-emitting layer 222 may include one or more of the following: a multi-quantum well layer for generating red light, a multi-quantum well layer for generating green light, and a multi-quantum well layer for generating blue light. The light-emitting chip 2 can emit different colors of light by configuring various different types of multi-quantum well layers.

[0099] Exemplarily, the second semiconductor layer 223 includes a first bottom surface 2231 facing the substrate 1, a first top surface 2232 facing away from the substrate 1, and a first side surface 2233 connecting the first bottom surface 2231 and the first top surface 2232. In some embodiments, the orthographic projection of the second semiconductor layer 223 onto the substrate is rectangular, and one second semiconductor layer 223 may include four first side surfaces 2233. As another example, the orthographic projection of the second semiconductor layer 223 onto the substrate is pentagonal, and one second semiconductor layer 223 may include five first side surfaces 2233. The embodiments of this disclosure do not impose specific limitations on the shape of the orthographic projection of the second semiconductor layer 223 onto the substrate.

[0100] For example, the light-emitting chip 2 may further include a second electrode 23. The second electrode 23 is electrically connected to the second semiconductor layer 223. The second electrode 23 can transmit a voltage signal to the second semiconductor layer 223, thereby forming charge carriers, such as electrons or holes, in the second semiconductor layer 223.

[0101] For example, the first electrode 21 is electrically connected to the first semiconductor layer 221. The first electrode 21 can transmit a voltage signal to the first semiconductor layer 221, thereby forming charge carriers, such as holes or electrons, in the first semiconductor layer 221.

[0102] When a voltage is applied to the first electrode 21 and the second electrode 23, electron-hole pairs can be generated in the first semiconductor layer 221 and the second semiconductor layer 223. These electron-hole pairs can recombine in the light-emitting layer 222 to generate excitons. The excitons then transition to form photons, which emit light. For example, the light-emitting chip 2 can emit light outward through the first top surface 2232.

[0103] It should be noted that although the embodiments of this disclosure show that the orthographic projection of the light-emitting body 22 on the substrate is rectangular, the embodiments of this disclosure are not limited to this. For example, the orthographic projection of the light-emitting body 22 on the substrate can be hexagonal, pentagonal, square, circular, or other shapes.

[0104] For example, the distance h3 between the surface 231 of the second electrode 23 near the substrate and the first surface 11 of the substrate is greater than the distance h4 between the first bottom surface 2231 and the first surface 11 of the substrate. That is, the second semiconductor layer 223 protrudes relative to the second electrode 23 in the direction toward the substrate 1.

[0105] For example, at least a portion of the second semiconductor layer 223 of the plurality of light-emitting chips 2 may be electrically connected via the second electrode 23.

[0106] Exemplarily, the material of the second electrode 23 may include an opaque conductive material. Here, "opaque" in the embodiments of this disclosure refers to a visible light transmittance of less than 30%. Exemplarily, the material of the second electrode 23 may be a metal or metal alloy. The thickness of the second electrode 23 is greater than 100 nanometers to ensure that the second electrode 23 is opaque. For example, the material of the second electrode 23 may be one or more of the following: gold, gold alloys, silver, silver alloys, aluminum, aluminum alloys, tungsten, copper, copper alloys, nickel, chromium, molybdenum, molybdenum alloys, titanium, and platinum. The second electrode 23 is located in the gap between adjacent light-emitting elements and is formed of an opaque material; therefore, light emitted outward from the light-emitting chip is difficult to pass through the second electrode 23 and enter the corresponding light-emitting area of ​​the adjacent light-emitting chip.

[0107] This design allows multiple light-emitting chips to share the second electrode 23 on their sidewalls (e.g., the first sidewall 2233). The second electrode 23 not only functions as an electrode for transmitting voltage signals but also acts as a light-shielding or pixel-limiting agent. For example, by employing an opaque design, the light-emitting area of ​​the light-emitting chip 2 can be adjusted, allowing it to emit light outwards through an opening VH. The second electrode 23 reduces the probability of light emitted from some of the light-emitting chips 2 entering the light-emitting areas of adjacent chips, thereby reducing optical crosstalk between adjacent chips. When the light-emitting substrate 100 is applied to a display device, the display effect of the device can be improved.

[0108] For example, refer to Figure 2 The orthographic projection of the second electrode 23 onto the substrate 1 falls into the gap between the orthographic projections of the multiple light-emitting elements 22 onto the substrate 1. The second electrode 23 can simultaneously shield multiple light-emitting elements, thereby reducing optical crosstalk between multiple light-emitting chips.

[0109] For example, refer to Figure 1 The shape of the orthographic projection of the second electrode 23 onto the substrate 1 can be a grid structure. Exemplarily, the shape and size of the second electrode 23 are related to the shape and spacing of the plurality of light-emitting elements 22. For example, the width of the portion of the second electrode located between two adjacent light-emitting elements is equal to the spacing width between these two light-emitting elements. This design ensures a good electrical connection between the second electrode 23 and a portion of the light-emitting elements (e.g., the second semiconductor layer 223), while also preventing light leakage gaps between the second electrode and the light-emitting elements, thereby preventing light from emanating from adjacent light-emitting chips through the gaps and causing optical crosstalk.

[0110] In some embodiments, the first side 2233 of the second semiconductor layer 223 in all light-emitting chips 2 of the light-emitting substrate 100 can be electrically connected through the second electrode 23. That is, all light-emitting chips 2 in the light-emitting substrate 100 can share the second electrode 23. The second electrode 23 can be a full-surface electrode, and the second electrode 23 includes multiple openings VH, which can expose multiple light-emitting bodies 22. The light-emitting chip 2 can emit light in the area where the multiple openings VH are located.

[0111] This design simplifies the connection of the second electrode, making it easier to connect multiple light-emitting chips to the external driving circuit. On the other hand, the second electrode provides better light shielding, reducing optical crosstalk between adjacent light-emitting chips.

[0112] For example, the light-emitting body 22 and the first electrode 21 are connected in a one-to-one correspondence. By selectively applying different voltage signals to the multiple first electrodes 21, the light-emitting body 22 can be controlled to emit light, thereby realizing different display images.

[0113] For example, the first electrode 21 and the second electrode 23 can be made of the same material. For instance, the first electrode 21 and the second electrode 23 can both be made of one or more of the following materials: gold, gold alloys, silver, silver alloys, aluminum, aluminum alloys, tungsten, copper, copper alloys, nickel, chromium, molybdenum, molybdenum alloys, titanium, and platinum.

[0114] For example, the thickness h0 of the first electrode 21 in the third direction Z can be substantially equal to the thickness h2 of the second electrode 23 in the third direction Z, where the third direction Z is parallel to the light emission direction of the light-emitting substrate. It should be noted that "substantially equal" here means that the ratio of the thickness h0 of the first electrode 21 to the thickness h2 of the second electrode 23 is in the range of 0.8 to 1.2.

[0115] For example, the first electrode 21 and the second electrode 23 can be located in the same layer. That is, the first electrode 21 and the second electrode 23 can be formed in the same coating process. It should be noted that, in this document, "same layer" refers to a layer structure formed by using the same film deposition process to form a film layer for forming a specific pattern, and then using the same mask to pattern the film layer in a single patterning process. Depending on the specific pattern, the single patterning process may include multiple exposure, development, or etching processes, and the specific pattern in the formed layer structure may be continuous or discontinuous. These specific patterns may also be at different heights. Multiple elements, components, structures, and / or portions located in the "same layer" are made of the same material and formed by the same single patterning process, and typically, multiple elements, components, structures, and / or portions located in the "same layer" have approximately the same thickness.

[0116] For example, continue to refer to Figure 2 The orthographic projection of the first electrode 21 onto the substrate 1 falls within the orthographic projection of the light-emitting body 22 onto the substrate 1. The orthographic projection of the second electrode 23 onto the substrate 1 falls within the gaps between the orthographic projections of the multiple light-emitting bodies 22 onto the substrate 1. The orthographic projections of the first electrode 21 and the second electrode 23 onto the substrate 1 do not overlap. That is, the first electrode 21 and the second electrode 23 are spaced apart in the first direction X and in the second direction Y. The first electrode 21 and the second electrode 23 do not interfere with each other on the plane formed by the first direction X and the second direction Y. Therefore, the first electrode 21 and the second electrode 23 can be formed in the same coating process.

[0117] In related technologies, the two electrodes of a light-emitting chip are typically located on opposite sides of the light-emitting body. For example, the first electrode is located below the first semiconductor layer, and the second electrode is located above the second semiconductor layer, wherein the first and second semiconductor layers are arranged opposite each other and parallel to each other. Due to the obstruction of the first and second semiconductor layers, the first and second electrodes cannot be formed in the same coating process. In related technologies, the two electrodes of the light-emitting chip need to be formed in at least two different coating processes.

[0118] The sidewall common second electrode design of the embodiments of this disclosure allows the second electrode 23 and the first electrode 21 to be spaced apart in both the first direction X and the second direction Y, enabling them to be formed in a single coating process. This reduces at least one coating process step, thus lowering production costs.

[0119] Figure 3 This is a partial cross-sectional schematic diagram of a light-emitting substrate according to an embodiment of the present disclosure.

[0120] Exemplarily, in embodiments of this disclosure, reference is made to Figure 3 The second electrode 23 may include a second top surface 232 facing away from the substrate 1. The second top surface 232 and the first top surface 2232 may form a planarized surface. For example, the distance h02 between the second top surface 232 and the surface 11 of the substrate 1 near the light-emitting chip is substantially equal to the distance h01 between the first top surface 2232 and the surface 11 of the substrate 1 near the light-emitting chip. The second top surface 232 and the first top surface 2232 may together form a planarized surface, that is, the second top surface 232 and the first top surface 2232 may be located in the same plane. It should be noted that "substantially equal" here means that the ratio of the distance h02 to the distance h01 is in the range of 0.8 to 1.2.

[0121] This design improves the surface flatness of the light-emitting substrate, which in turn enhances its luminescence quality. Furthermore, the planarized surface design of the substrate facilitates subsequent fabrication processes, such as… Figure 7 The preparation of the third electrode 40 in the illustrated embodiment, or Figure 8 The preparation of the color conversion layer 80 in the illustrated embodiment can save additional planarization process steps, which helps to reduce costs.

[0122] The second semiconductor layer 223 has a first thickness h1 in the third direction Z, and the second electrode 23 has a second thickness h2 in the third direction Z. The first thickness h1 is greater than the second thickness h2. The third direction Z is parallel to the light emission direction of the light-emitting substrate 100.

[0123] For example, the first thickness h1 is in the range of 3 micrometers to 4 micrometers.

[0124] For example, the second thickness h2 is less than 1 micrometer.

[0125] This design ensures that the second electrode 23 has good conductivity while maintaining electrical connection between the second electrode 23 and the second semiconductor layer 223 in the light-emitting body 22, and disconnection between the second electrode 23 and other parts of the light-emitting body 22. For example, the second electrode 23 is disconnected from the light-emitting layer 222 and from the first semiconductor layer 221. Therefore, the probability of short circuits or leakage in the light-emitting chip can be reduced, which is beneficial to improving the luminous efficiency of the light-emitting chip.

[0126] For example, the orthographic projection of the first semiconductor layer 221 on the substrate 1 and the orthographic projection of the light-emitting layer 222 on the substrate 1 can completely overlap. For instance, the first semiconductor layer 221 and the light-emitting layer 222 can form a mesa in the same etching process, which can simplify the process flow, save the number of photomasks, and help reduce costs.

[0127] For example, the orthographic projection of the light-emitting layer 222 on the substrate 1 and the orthographic projection of the second semiconductor layer 223 on the substrate 1 can completely overlap. The light-emitting layer 222 and the second semiconductor layer 223 can form mesa in the same etching process, which can simplify the process flow, save the number of photomasks, and help reduce costs.

[0128] In some embodiments, the orthographic projections of the first semiconductor layer 221, the light-emitting layer 222, and the second semiconductor layer 223 on the substrate completely overlap. The first semiconductor layer 221, the light-emitting layer 222, and the second semiconductor layer 223 can be formed in a single etching process. This design not only simplifies the process flow, reduces the number of photomasks, and lowers costs, but also allows the second electrode to be electrically connected to the first sidewall of the second semiconductor layer 223 during subsequent fabrication, while avoiding connection between the second electrode and the sidewalls of the light-emitting layer 222 or the first semiconductor layer 221. This helps reduce the probability of short circuits or leakage in the light-emitting chip, thereby improving the reliability and luminous efficiency of the chip.

[0129] It should be noted that "complete overlap" in the embodiments of this disclosure includes both theoretical complete overlap and complete overlap within the limits allowed by the manufacturing process. Considering factors such as process variations, measurement issues, and errors related to the measurement of specific quantities, "complete overlap" here also includes situations where the deviation value is within an acceptable range as determined by a person skilled in the art. For example, "complete overlap" of a single first semiconductor layer and a single light-emitting layer includes theoretical complete overlap, and also includes situations where the boundary spacing between the single first semiconductor layer and the single light-emitting layer does not exceed 5% or 3% of the dimension of either the single first semiconductor layer or the single light-emitting layer in the corresponding direction.

[0130] Figure 4 This is a partial cross-sectional schematic diagram of a light-emitting substrate according to an embodiment of the present disclosure. Figure 5 This is a projection relationship diagram of the main body portion and the passivation portion in the first semiconductor layer according to an embodiment of the present disclosure.

[0131] Exemplarily, in embodiments of this disclosure, reference is made to Figure 4 and Figure 5 The first semiconductor layer 221 may include a main body portion 2211 and a passivation portion 2212. The main body portion 2211 and the passivation portion 2212 are disposed adjacent to each other. The passivation portion 2212 is disposed around the main body portion 2211, such that the sidewalls of the main body portion 2211 are surrounded by the passivation portion 2212.

[0132] For example, the height h5 of the main body 2211 in the third direction Z can be equal to the height h6 of the passivation part 2212 in the third direction Z.

[0133] For example, the first semiconductor layer 221 includes a side region S1 and a central region S2. The side region S1 surrounds the central region S2. The main body portion 2211 is located in the central region S2. The passivation portion 2212 is located in the side region S1. For example, when the shape of the orthographic projection of the first semiconductor layer 221 onto the substrate is rectangular, the side region S1 of the first semiconductor layer 221 includes a first side region S11, a second side region S12, a third side region S13, and a fourth side region S14. The first side region S11, the second side region S12, the third side region S13, and the fourth side region S14 completely surround the central region S2.

[0134] For example, the resistance of the passivation portion 2212 is greater than the resistance of the main body portion 2211, and the passivation portion 2212 can provide passivation protection for the first semiconductor layer 221. For example, the ratio of the resistance of the passivation portion 2212 to the resistance of the main body portion 2211 is greater than 2.6. Because the resistance of the passivation portion 2212 is relatively large, the probability of electrons and holes moving to the passivation portion 2212 is low, which can reduce the probability of electron-hole pairs recombination in the side region S1, thereby reducing the probability of light leakage from the sidewall of the light-emitting chip, which is beneficial to improving the front light emission efficiency and front light emission brightness of the light-emitting chip.

[0135] For example, the width d1 of the main body portion 2211 in the first direction X is greater than the width d2 of the passivation portion 2212 in the first direction X.

[0136] For example, the width d3 of the main body portion 2211 in the second direction Y is greater than the width d4 of the passivation portion 2212 in the second direction Y.

[0137] With this design, a high-concentration carrier injection region, such as the region corresponding to the main body 2211, and a low-concentration carrier injection region, such as the region corresponding to the passivation portion 2212, can be formed in the first semiconductor layer 221. Since the passivation portion 2212 is located in the side region, the electron-hole pair concentration in the side region S1 of the light-emitting chip is lower than that in the central region S2. Electron-hole pairs mainly recombine and emit light in the central region S2, which helps to reduce sidewall light emission of the light-emitting chip and thus improves the front light emission efficiency of the light-emitting chip.

[0138] For example, the passivation portion 2212 can be formed by ion implantation. For instance, heavy ions such as F-, Ar+, and Kr+ can be implanted. By adjusting the implantation energy in the ion implantation process, the resistance and width of the passivation portion 2212 can be adjusted. For example, increasing the implantation energy can increase the resistance and width of the passivation portion, thereby resulting in a better passivation effect.

[0139] In some embodiments, the resistance ratio of the passivation portion 2212 to the resistance of the body portion 2211 is greater than 2.6. For example, the first semiconductor layer 221 is an N-type semiconductor, such as n-GaN. The resistance of the body portion 2211 of the first semiconductor layer 221 is approximately 2.5 kΩ. Ions are implanted into the side region S1 of the first semiconductor layer 221 to form the passivation portion 2212. The resistance of the passivation portion 2212 increases with increasing implantation energy. For example, when the implantation energy is 50 keV, the resistance of the passivation portion 2212 is approximately 0.03 MΩ, and the resistance ratio of the passivation portion 2212 to the resistance of the body portion 2211 is approximately 12. When the implantation energy is 100 keV, the resistance of the passivation portion 2212 is approximately 0.22 MΩ, and the resistance ratio of the passivation portion 2212 to the resistance of the body portion 2211 is approximately 88. The greater the ratio of the resistance of the passivation portion 2212 to the resistance of the main body portion 2211, the smaller the ratio of the concentration of electron-hole pairs in the passivation portion 2212 to the concentration of electron-hole pairs in the main body portion 2211. The lower the probability of electron-hole pair recombination luminescence in the passivation portion 2212, the better the light leakage from the sidewalls of the light-emitting chip can be reduced.

[0140] In some embodiments, the first semiconductor layer 221 is a P-type semiconductor, such as p-GaN. The resistance of the main body portion 2211 of the first semiconductor layer 221 is approximately 15 kΩ. Ions are implanted into the side region S1 of the first semiconductor layer 221 to form a passivation portion 2212. The resistance of the passivation portion 2212 increases with increasing implantation energy. For example, when the implantation energy is 50 keV, the resistance of the passivation portion 2212 is approximately 0.04 MΩ, and the ratio of the resistance of the passivation portion 2212 to the resistance of the main body portion 2211 is approximately 2.67. When the implantation energy is 100 keV, the resistance of the passivation portion 2212 is approximately 5.06 MΩ, and the ratio of the resistance of the passivation portion 2212 to the resistance of the main body portion 2211 is approximately 337. The greater the ratio of the resistance of the passivation portion 2212 to the resistance of the main body portion 2211, the smaller the ratio of the concentration of electron-hole pairs in the passivation portion 2212 to the concentration of electron-hole pairs in the main body portion 2211. The lower the probability of electron-hole pair recombination luminescence in the passivation portion 2212, the better the light leakage from the sidewalls of the light-emitting chip can be reduced.

[0141] The width of the passivation portion can be adjusted by regulating the injection energy. For example, the size of the passivation portion can be on the nanometer scale, with its width ranging from 10 nanometers to 900 nanometers. The size of the main body portion can be on the micrometer scale, with its width ranging from 1 micrometer to 100 micrometers.

[0142] It should be noted that although the embodiments of this disclosure show that the orthographic projection of the main body 22111 on the substrate is rectangular and the orthographic projection of the passivation portion 2212 on the substrate is a rectangular ring, the embodiments of this disclosure are not limited to this. In some embodiments, the orthographic projection of the main body 2211 on the substrate can be hexagonal, pentagonal, square, circular, or other shapes. Correspondingly, the orthographic projection of the passivation portion 2212 on the substrate can be an annular shape with a corresponding shape to the main body 2211, so as to ensure that the sidewalls of the main body 2211 are all surrounded by the passivation portion 2212.

[0143] Figure 6A and Figure 6B This is a partial cross-sectional schematic diagram of a light-emitting substrate according to an embodiment of the present disclosure.

[0144] Exemplarily, in embodiments of this disclosure, reference is made to Figure 6A and Figure 6B The light-emitting substrate 100 may further include a filling layer 3, which includes at least one filling portion 30. The filling portion 30 is located between two adjacent light-emitting chips 2.

[0145] For example, the material of the filling layer 3 may include an insulating material, and the filling layer 3 can serve to isolate and support the multiple light-emitting chips 2. For example, the material of the filling layer 3 may include organic or inorganic materials.

[0146] For example, the filling portion 30 may include: a first portion 301 located between two adjacent light-emitting bodies 22; and a second portion 302 located between two adjacent first electrodes 21.

[0147] For example, the width d5 ​​of the first part 301 in the first direction X is smaller than the width d6 of the second part 302 in the first direction X.

[0148] For example, the width d7 of the first part 301 in the second direction Y is smaller than the width d8 of the second part 302 in the second direction Y.

[0149] For example, the surface 303 of the filling portion 30 near the substrate 1 and the surface 211 of the first electrode 21 near the substrate 1 can be planarized. This design facilitates the bonding connection between the first electrode 21 and the driving circuit layer in subsequent processes.

[0150] For example, continue to refer to Figure 6A The light-emitting substrate 100 may also include a driving circuit layer 101 located between the substrate 1 and the light-emitting chip 2.

[0151] For example, at least a portion of the plurality of first electrodes 21 in the plurality of light-emitting chips 2 can be bonded to the driving circuit layer 101. For example, the driving circuit layer 101 may include a plurality of driving units 1011. The plurality of driving units 1011 can be connected one-to-one with the plurality of first electrodes 21.

[0152] In some embodiments, the substrate 1 may be a silicon substrate. The driving circuit layer 101 may be embedded in the silicon substrate.

[0153] Figure 7 A partial cross-sectional schematic diagram of a light-emitting substrate according to an embodiment of the present disclosure.

[0154] Exemplarily, in embodiments of this disclosure, reference is made to Figure 7 The light-emitting substrate 100 may include a third electrode 40 located on the side of the second electrode 23 away from the substrate 1. For example, the third electrode 40 may be a full-surface electrode.

[0155] The third electrode 40 is electrically connected to the second electrode 23, thus forming a double-layer electrode with the second electrode 23. With this design, the third electrode 40 and the second electrode 23 can jointly serve as the N-electrode or P-electrode of the light-emitting chip, thereby reducing the voltage drop on the N-electrode or P-electrode and improving the consistency of light emission from multiple light-emitting chips.

[0156] For example, the material of the third electrode 40 may include a transparent conductive material, such as ITO.

[0157] Exemplarily, the orthographic projections of the second electrode 23 and the plurality of light-emitting bodies 22 on the substrate can all fall within the orthographic projection of the third electrode 40 on the substrate. The third electrode 40 can be electrically connected to at least a portion of the plurality of second semiconductor layers 223. In some embodiments, the third electrode 40 can be electrically connected to each of the plurality of second semiconductor layers 223.

[0158] This design ensures the luminous efficiency of the light-emitting chip in the luminous area while further reducing the voltage drop on the electrodes of the light-emitting chip, thereby improving the overall luminous consistency of multiple light-emitting chips.

[0159] In related technologies, colorization schemes for Micro LED display devices include using monochrome Micro LED light-emitting chips combined with quantum dot layers (such as quantum dot films) to achieve color display. The mainstream method involves first fabricating a substrate containing a quantum dot layer, then fabricating a driving substrate containing monochrome Micro LED light-emitting chips (such as blue Micro LED light-emitting chips), and finally aligning and bonding the two together. However, this method involves numerous process steps and the flipping and alignment of the two substrates. If the alignment accuracy is low, it can cause optical crosstalk between adjacent pixels.

[0160] The embodiments of this disclosure provide a light-emitting substrate in which a point-to-point quantum dot layer can be fabricated directly on the back side of the second semiconductor layer. This reduces the number of process steps for flipping quantum dots onto a monochromatic Micro LED light-emitting chip array, making the fabrication method simpler and eliminating the need to consider alignment accuracy.

[0161] Figure 8 A partial cross-sectional schematic diagram of a light-emitting substrate according to an embodiment of the present disclosure.

[0162] Exemplarily, in embodiments of this disclosure, reference is made to Figure 8 The light-emitting substrate 100 may include a color conversion layer 80 located on the side of the second semiconductor layer 223 away from the substrate 1. The light-emitting chip 2 may be a monochrome Micro LED light-emitting chip, for example, a blue Micro LED light-emitting chip. The light emitted by the monochrome Micro LED light-emitting chip can be converted into other colors after passing through the color conversion layer 80, or it can remain in its previous color, thus presenting a color display to the outside world.

[0163] For example, the light-emitting element in the light-emitting chip 2 can be configured to emit light of a third wavelength. After passing through the color conversion layer 80, the third wavelength light can be converted into any one of the first, second, or third wavelengths. The third wavelength is shorter than both the second and first wavelengths. For example, the third wavelength light is blue light, the first wavelength light is red light, and the second wavelength light is green light. That is, some blue Micro LED light-emitting chips can emit red or green light after passing through the color conversion layer. Some blue Micro LED light-emitting chips can remain blue after passing through the color conversion layer, i.e., emit blue light. Through the combined design of the monochromatic Micro LED light-emitting chip array and the color conversion layer, color display can be achieved.

[0164] Since monochrome Micro LED light-emitting chips have good consistency in terms of brightness, lifespan, and decay rate, the combination design of monochrome Micro LED light-emitting chips and color conversion layers can improve the overall consistency of the light-emitting substrate in terms of brightness, lifespan, decay rate, and other aspects, thereby improving the display effect of the display device.

[0165] For example, continue to refer to Figure 8 The color conversion layer 80 may include a plurality of first color conversion units 81 arranged in an array. The first color conversion units 81 are configured to generate light of a first wavelength when excited by light emitted by the light-emitting body 22. For example, the first color conversion units 81 may include red quantum dots, the light emitted by the light-emitting body 22 may be blue light, and the first color conversion units 81 may generate light of a first wavelength, such as red light, when excited by blue light.

[0166] For example, a plurality of first color conversion units 81 are provided in a one-to-one correspondence with a portion of a plurality of light-emitting bodies 22, and the orthographic projection of the light-emitting body 22 on the substrate falls into the orthographic projection of the corresponding first color conversion unit 81 on the substrate.

[0167] With this design, it can be ensured that the light emitted by the light-emitting body 22 corresponding to the first color conversion unit 81 (e.g., blue light) needs to be converted by the first color conversion unit 81 (e.g., converted into red light) before being emitted outward. This can improve the color purity of the light-emitting area corresponding to a single light-emitting chip, which is beneficial to improving the display effect of the display device.

[0168] For example, the color conversion layer 80 may further include a plurality of second color conversion units 82 arranged in an array. The second color conversion units 82 are configured to generate light of a second wavelength, which is smaller than the first wavelength, when excited by light (e.g., blue light) emitted by the light-emitting body 22.

[0169] For example, the second color conversion unit 82 may include green quantum dots, and the light emitted by the light-emitting body 22 may be blue light. When excited by blue light, the second color conversion unit 82 may generate light of a second wavelength, such as green light.

[0170] For example, a plurality of second color conversion units 82 are provided in one-to-one correspondence with a portion of a plurality of light-emitting bodies 22, and the orthographic projection of the light-emitting body 22 on the substrate falls into the orthographic projection of the corresponding second color conversion unit 82 on the substrate.

[0171] With this design, it can be ensured that the light emitted by the light-emitting body 22 corresponding to the second color conversion unit 82 (e.g., blue light) needs to be converted by the second color conversion unit 82 (e.g., converted into green light) before being emitted outward. This can improve the color purity of the light-emitting area corresponding to a single light-emitting chip, which is beneficial to improving the display effect of the display device.

[0172] For example, the color conversion layer 80 may further include a plurality of first scattering portions 83 arranged in an array, the first scattering portions 83 being configured such that the wavelength of light passing through the first scattering portions 83 remains substantially unchanged. For example, the first scattering portions 83 may include a plurality of scattering particles. Light emitted by the light-emitting entity (e.g., blue light) remains blue light after passing through the first scattering portions 83.

[0173] For example, a plurality of first scattering portions 83 are arranged one-to-one with a portion of a plurality of light-emitting bodies 22, and the orthographic projection of the light-emitting body 22 on the substrate falls into the orthographic projection of the corresponding first scattering portion 83 on the substrate.

[0174] This design ensures that all light emitted by the light-emitting body 22 corresponding to the first scattering section 83 (e.g., blue light) must pass through the first scattering section 83 before being emitted outward. The scattering particles in the first scattering section 83 can change the exit angle of the light entering it, making the emitted light more uniform and thus improving the display effect of the display device.

[0175] For example, a plurality of first color conversion units 81, a plurality of second color conversion units 82 and a plurality of first scattering units 83 are all spaced apart.

[0176] For example, the color conversion layer 80 may further include a plurality of isolation pillars 84 disposed in the gaps between any two of the first color conversion portion 81, the second color conversion portion 82, and the first scattering portion 83. For example, the isolation pillars may be formed of an organic material. For example, the isolation pillars may be made of a material with poor light transmittance, such as a visible light transmittance of less than 20% or 10%.

[0177] This design reduces optical crosstalk between light rays from adjacent light-emitting chips.

[0178] Exemplarily, the orthographic projection of the isolation pillar 84 on the substrate at least partially overlaps with the orthographic projection of the second electrode 23 on the substrate. In some embodiments, the orthographic projection of the isolation pillar 84 on the substrate may fall entirely within the orthographic projection of the second electrode 23 on the substrate.

[0179] For example, at least one of the first color conversion section 81, the second color conversion section 82, and the first scattering section 83 has an inverted trapezoidal shape. For instance, the shapes of the first color conversion section 81, the second color conversion section 82, and the first scattering section 83 can all be inverted trapezoidal.

[0180] For example, at least one isolation post 84 is in the shape of a regular trapezoid. For example, multiple isolation posts 84 may all be in the shape of a regular trapezoid.

[0181] In some embodiments, the method for preparing the color conversion layer 80 includes first preparing isolation pillars 84, and then preparing a first color conversion portion 81, a second color conversion portion 82, and a first scattering portion 83 in the gaps between the isolation pillars using inkjet printing technology. The isolation pillars 84 adopt a trapezoidal design, which can ensure that the material subsequently printed by inkjet printing can more fully fill the gaps between the isolation pillars, thereby improving the overall film quality of the color conversion layer.

[0182] It should be noted that the arrangement of the first color conversion section, the second color conversion section, and the first scattering section can be designed according to the specific pixel arrangement of the display device, and the embodiments disclosed herein do not impose specific limitations on this.

[0183] Figure 9 This is a flowchart illustrating the fabrication process of a light-emitting substrate according to an embodiment of the present disclosure. Figures 10A-10H These are schematic cross-sectional views of some film layers during the fabrication process of the light-emitting substrate according to embodiments of the present disclosure.

[0184] By way of example, embodiments of this disclosure also provide a method for fabricating a light-emitting substrate. (Referring to...) Figures 9-10H The method for preparing the light-emitting substrate may include the following steps S01-S09.

[0185] In step S01, a temporary substrate 50 is provided. For example, the temporary substrate 50 may include one of a sapphire substrate, a silicon carbide substrate, or a silicon substrate.

[0186] In step S02, refer to Figure 10A A second semiconductor material layer 2230, a light-emitting material layer 2220, and a first semiconductor material layer 2210 are sequentially stacked on a temporary substrate 50. For example, the second semiconductor material layer 2230 can be n-GaN, and the first semiconductor material layer 2210 can be p-GaN. The light-emitting material layer 2220 can be a multi-quantum-well material layer.

[0187] In step S03, refer to... Figure 10B and Figure 10C Multiple passivation portions 2212 are formed in an array in multiple regions of the first semiconductor material layer 2210 using patterning and ion implantation processes. For example, a mask layer 60 is formed on the side of the first semiconductor material layer 2210 away from the temporary substrate 50. The material of the mask layer 60 may include silicon oxide. The mask layer 60 can be etched according to the size of the light-emitting chip to form an array including multiple mask portions 601. Ions, such as F-, Ar+, Kr+, etc., are implanted in the spacer regions of the array of mask portions 601 to form multiple passivation portions 2212 in an array in multiple regions of the first semiconductor material layer 2210. After the step of forming multiple passivation portions 2212, the mask layer 60 can be removed.

[0188] In step S04, refer to... Figure 10C and Figure 10D A patterning process is performed on the first semiconductor material layer 2210, the light-emitting material layer 2220, and the second semiconductor material layer 2230 to form multiple arrayed light-emitting bodies 22. Each light-emitting body 22 includes a second semiconductor layer 223, a light-emitting layer 222, and a first semiconductor layer 221, sequentially located away from the temporary substrate 50. The first semiconductor layer 221 includes a main body portion 2211 and a passivation portion 2212, with the passivation portion 2212 surrounding the main body portion 2211. Exemplarily, the first semiconductor material layer 2210, the light-emitting material layer 2220, and the second semiconductor material layer 2230 can be etched in a single step, thereby reducing process steps, saving on the number of photomasks, and lowering production costs.

[0189] In step S05, refer to Figure 10E An electrode material layer 20 is formed on the side of the first semiconductor layer 221 away from the temporary substrate 50, and a patterning process is performed to form a first electrode 21 and a second electrode 23. The first sides 2233 of a plurality of second semiconductor layers 223 are electrically connected through the second electrodes 23.

[0190] In step S06, continue to refer to Figure 10F A filling material layer is formed in the gap between the light-emitting body 22 and the gap between the first electrode 21, and a patterning process is performed to form the filling layer 3. The filling layer 3 may include a plurality of filling portions 30.

[0191] In step S07, refer to Figure 10G Remove the temporary substrate 50 to form an epitaxial layer 300 containing multiple light-emitting chips.

[0192] In step S08, refer to Figure 10H A driving backplane 10 is provided. For example, the driving backplane 10 can be a CMOS driving backplane. Exemplarily, the driving backplane 10 may include a substrate 1 and a driving circuit layer 101.

[0193] In step S09, continue to refer to Figure 10H Multiple first electrodes 21 in the epitaxial layer 300 are bonded to the driving circuit layer 101 to form a light-emitting substrate 100.

[0194] Figure 11 This is a partial fabrication flowchart of a light-emitting substrate according to an embodiment of the present disclosure. Figures 12A-12E These are schematic cross-sectional views of some film layers during the fabrication process of the light-emitting substrate according to embodiments of the present disclosure.

[0195] By way of example, embodiments of this disclosure also provide a method for fabricating a light-emitting substrate. This method can directly fabricate a point-to-point quantum dot layer on the back side of the second semiconductor layer, thereby reducing the process steps of flipping quantum dots onto a monochromatic Micro LED light-emitting chip array, making the fabrication method simpler, and eliminating the need to consider alignment accuracy.

[0196] For example, the method for fabricating a light-emitting substrate may include, after completing steps S01-S07 of the aforementioned embodiment to obtain an epitaxial layer 300 containing multiple light-emitting chips, continuing to perform steps S11-S15 as follows. In step S11, referring to... Figure 12A The epitaxial layer 300 is transferred onto the first substrate 111. The first surface 3001 of the epitaxial layer 300, which is close to the first electrode 21, is disposed on the first substrate 111.

[0197] In step S12, refer to Figure 12B An isolation pillar material layer is deposited on the second surface 3002 of the epitaxial layer 300, and a patterning process is performed on the isolation pillar material layer to form a plurality of isolation pillars 84 arranged in a grid. The second surface 3002 is the surface of the epitaxial layer 300 near the second electrode 23. Exemplarily, the material of the isolation pillars 84 can be an organic material. Through the patterning process, the isolation pillars 84 can be distributed in a grid, thereby defining multiple spacer regions. Exemplarily, a single isolation pillar can be designed in a trapezoidal shape, thereby facilitating the filling of other materials in the spacer regions defined by adjacent isolation pillars. In step S13, refer to... Figure 12C A color conversion material layer is filled into the gaps of the isolation pillars 84 using a printing technology (such as inkjet printing) to form a color conversion layer 80. The color conversion layer 80 may include a plurality of first color conversion portions 81, a plurality of second color conversion portions 82, and a plurality of first scattering portions 83.

[0198] In step S14, refer to Figure 12D An encapsulation layer 90 is formed on the side of the color conversion layer 80 away from the first substrate 111.

[0199] In step S15, refer to Figure 12E Remove the first substrate 111 to obtain another light-emitting structure 310 containing multiple light-emitting chips and a color conversion layer.

[0200] For example, after completing step S15, the same or corresponding steps as those in S08-S09 of the aforementioned embodiments can be used to bond the light-emitting structure 310, which includes multiple light-emitting chips and a color conversion layer, to the driving backplate 10, to obtain the following: Figure 8 The light-emitting substrate shown.

[0201] This method reduces the number of process steps involved in flipping quantum dots onto a monochromatic Micro LED light-emitting chip array, simplifying the fabrication process and lowering costs. Furthermore, the fabrication method in this disclosure does not require consideration of alignment accuracy, thereby improving the yield of the light-emitting substrate.

[0202] Figure 13 This is a structural block diagram of a display device according to an embodiment of the present disclosure.

[0203] Optionally, embodiments of this disclosure also provide a display device, referring to... Figure 13 The display device 1000 may include the aforementioned light-emitting substrate 100. The display device may include, but is not limited to, any product or component with a display function, such as electronic paper, mobile phone, tablet computer, monitor, laptop computer, digital photo frame, or navigator. It should be understood that this display device has the same beneficial effects as the light-emitting substrate 100 provided in the foregoing embodiments.

[0204] While some embodiments of the general concept of this disclosure have been shown and described, those skilled in the art will understand that changes may be made to these embodiments without departing from the principles and spirit of the general concept of this disclosure, the scope of which is defined by the claims and their equivalents.

Claims

1. A light-emitting substrate, characterized in that, Includes a substrate and multiple light-emitting chips disposed on the substrate; The light-emitting chip includes: a first electrode and a light-emitting body located on the side of the first electrode away from the substrate, and a plurality of light-emitting bodies are arranged in an array in a first direction and a second direction; The light-emitting body includes: a first semiconductor layer located on the side of the first electrode away from the substrate; a light-emitting layer located on the side of the first semiconductor layer away from the substrate; and a second semiconductor layer located on the side of the light-emitting layer away from the substrate, the second semiconductor layer including a first bottom surface facing the substrate, a first top surface away from the substrate, and a first side surface connected between the first bottom surface and the first top surface; The light-emitting chip further includes a second electrode, wherein the distance between the surface of the second electrode near the substrate and the first surface of the substrate is greater than the distance between the first bottom surface and the first surface of the substrate; and The first side of the second semiconductor layer of at least a portion of the plurality of light-emitting chips is electrically connected via the second electrode.

2. The light-emitting substrate according to claim 1, wherein, The first electrode and the second electrode are made of the same material; and / or, The thickness of the first electrode in the third direction is substantially equal to the thickness of the second electrode in the third direction, and the third direction is parallel to the light emission direction of the light-emitting substrate.

3. The light-emitting substrate according to claim 1 or 2, wherein, The orthographic projection of the second electrode on the substrate falls into the gap between the orthographic projections of the plurality of light-emitting bodies on the substrate.

4. The light-emitting substrate according to claim 3, wherein, The second electrode has a grid-like shape when projected onto the substrate.

5. The light-emitting substrate according to any one of claims 1-4, wherein, The second electrode includes a second top surface facing away from the substrate, and the distance between the second top surface and the first surface of the substrate is substantially equal to the distance between the first top surface and the first surface of the substrate.

6. The light-emitting substrate according to claim 5, wherein, The second semiconductor layer has a first thickness in a third direction, and the second electrode has a second thickness in the same third direction. The first thickness is greater than the second thickness, and the third direction is parallel to the light emission direction of the light-emitting substrate.

7. The light-emitting substrate according to claim 6, wherein, The first thickness is in the range of 3 micrometers to 4 micrometers; and / or, The second thickness is less than 1 micrometer.

8. The light-emitting substrate according to any one of claims 1-7, wherein, The material of the second electrode includes an opaque conductive material.

9. The light-emitting substrate according to claim 8, wherein, The first semiconductor layer includes a body portion and a passivation portion, the body portion and the passivation portion being disposed adjacent to each other; and the passivation portion surrounding the body portion.

10. The light-emitting substrate according to claim 9, wherein, The ratio of the resistance of the passivation portion to the resistance of the main body portion is greater than 2.6; and / or, The width of the main body portion in the first direction is greater than the width of the passivation portion in the first direction; And / or, The width of the main body portion in the second direction is greater than the width of the passivation portion in the second direction.

11. The light-emitting substrate according to any one of claims 1-10, wherein, The orthographic projection of the first semiconductor layer on the substrate completely overlaps with the orthographic projection of the light-emitting layer on the substrate; And / or, The orthogonal projection of the light-emitting layer on the substrate completely overlaps with the orthogonal projection of the second semiconductor layer on the substrate.

12. The light-emitting substrate according to claim 11, wherein, The light-emitting substrate further includes a filling layer, the filling layer including at least one filling portion, the filling portion being located between two adjacent light-emitting chips; The filling portion includes: a first portion located between two adjacent light-emitting bodies; and a second portion located between two adjacent first electrodes. Wherein, the width of the first portion in the first direction is smaller than the width of the second portion in the first direction; and The width of the first part in the second direction is smaller than the width of the second part in the second direction.

13. The light-emitting substrate according to claim 12, wherein, The light-emitting substrate further includes a driving circuit layer located between the substrate and the light-emitting chip; as well as At least a portion of the plurality of first electrodes in the plurality of light-emitting chips are bonded to the driving circuit layer.

14. The light-emitting substrate according to any one of claims 1-13, wherein, The light-emitting substrate further includes a third electrode located on the side of the second electrode away from the substrate, the third electrode being electrically connected to the second electrode; and The third electrode is electrically connected to at least a portion of the plurality of second semiconductor layers.

15. The light-emitting substrate according to claim 14, wherein, The third electrode is a full-surface electrode; and The material of the third electrode includes a transparent conductive material.

16. The light-emitting substrate according to any one of claims 1-13, wherein, The light-emitting substrate further includes a color conversion layer located on the side of the second semiconductor layer away from the substrate. The color conversion layer includes a plurality of first color conversion sections arranged in an array. The first color conversion sections are configured to generate light of a first wavelength when excited by light emitted by the light-emitting body. In this configuration, a plurality of first color conversion units are arranged in a one-to-one correspondence with a portion of a plurality of light-emitting bodies, and the orthographic projection of the light-emitting body on the substrate falls within the orthographic projection of the corresponding first color conversion unit on the substrate.

17. The light-emitting substrate according to claim 16, wherein, The color conversion layer further includes a plurality of second color conversion units arranged in an array. The second color conversion units are configured to generate light of a second wavelength when excited by light emitted by the light-emitting body. The second wavelength is shorter than the first wavelength. In this configuration, a plurality of second color conversion units are arranged in a one-to-one correspondence with a portion of a plurality of light-emitting bodies, and the orthogonal projection of the light-emitting body on the substrate falls within the orthogonal projection of the corresponding second color conversion unit on the substrate.

18. The light-emitting substrate according to claim 16 or 17, wherein, The color conversion layer further includes multiple arrayed first scattering sections, which are configured such that the wavelength of light passing through the first scattering sections remains substantially unchanged. In this configuration, a plurality of the first scattering portions are arranged in a one-to-one correspondence with a portion of the plurality of light-emitting bodies, and the orthogonal projection of the light-emitting body on the substrate falls within the orthogonal projection of the corresponding first scattering portion on the substrate.

19. The light-emitting substrate according to claim 18, wherein, The light-emitting body is configured to emit light of a third wavelength, which is smaller than both the second wavelength and the first wavelength.

20. The light-emitting substrate according to claim 18, wherein, A plurality of first color conversion units, a plurality of second color conversion units, and a plurality of first scattering units are all spaced apart; and The color conversion layer further includes a plurality of isolation pillars disposed in the gap between any two of the first color conversion section, the second color conversion section and the first scattering section, wherein the orthographic projection of the isolation pillars on the substrate at least partially overlaps with the orthographic projection of the second electrode on the substrate.

21. The light-emitting substrate according to claim 20, wherein, At least one of the first color conversion section, the second color conversion section, and the first scattering section is in the shape of an inverted trapezoid; and / or, At least one of the isolation columns is trapezoidal in shape.

22. The light-emitting substrate according to any one of claims 18-21, wherein, The light-emitting chip includes a Micro-LED light-emitting chip; and / or, The light-emitting layer includes a multi-quantum-well layer; and / or, The first color conversion unit includes red quantum dots; and / or, The second color conversion unit includes green quantum dots; The first scattering part includes multiple scattering particles.

23. A display device, wherein, The display device includes a light-emitting substrate as described in any one of claims 1-22.

24. A method for preparing a light-emitting substrate, characterized in that, The method includes: Provide temporary substrate; A second semiconductor material layer, a light-emitting material layer, and a first semiconductor material layer are sequentially stacked on the temporary substrate. Multiple passivation portions are formed in an array in multiple regions of the first semiconductor material layer using patterning and ion implantation processes. A patterning process is performed on the first semiconductor material layer, the light-emitting material layer, and the second semiconductor material layer to form a plurality of light-emitting bodies arranged in an array, wherein the light-emitting body includes a second semiconductor layer, a light-emitting layer, and a first semiconductor layer that are sequentially moved away from the temporary substrate; and the first semiconductor layer includes a body portion and a passivation portion, wherein the passivation portion surrounds the body portion; An electrode material layer is formed on the side of the first semiconductor layer away from the temporary substrate, and a patterning process is performed to form a first electrode and a second electrode, wherein a plurality of first sides of the second semiconductor layer are electrically connected through the second electrode. A filling material layer is formed in the gap between the light-emitting body and the gap between the first electrode, and a patterning process is performed to form the filling layer; Remove the temporary substrate to form an epitaxial layer containing multiple light-emitting chips; A driving backplane is provided, the driving backplane including a substrate and a driving circuit layer; and The plurality of first electrodes in the epitaxial layer are bonded to the driving circuit layer to form the light-emitting substrate.

25. The method according to claim 24, wherein, After obtaining the epitaxial layer containing multiple light-emitting chips and before providing the driving backplane, the method further includes: The epitaxial layer is transferred onto a first substrate, wherein a first surface of the epitaxial layer near the first electrode is disposed on the first substrate; An isolation pillar material layer is deposited on the second surface of the epitaxial layer, and a patterning process is performed on the isolation pillar material layer to form a plurality of isolation pillars arranged in a grid, wherein the second surface is the surface of the epitaxial layer near the second electrode; A color conversion material layer is filled into the gaps of the isolation pillars using printing technology to form a color conversion layer, the color conversion layer including a plurality of first color conversion parts, a plurality of second color conversion parts, and a plurality of first scattering parts; An encapsulation layer is formed on the side of the color conversion layer away from the first substrate; and Remove the first substrate.

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