Light-emitting substrate, preparation method thereof and display device

Abstract

The embodiment of the invention provides a light-emitting substrate, a preparation method thereof and a display device, relates to the technical field of display, and is used for reducing the area of a high-voltage light-emitting diode and improving the pixel density of the light-emitting substrate. The light-emitting substrate comprises a driving back plate and a plurality of light-emitting devices arranged on the driving back plate. The driving backboard comprises a plurality of driving circuits, and one light-emitting device is connected with one driving circuit. The light-emitting device comprises a plurality of device layers which are stacked in the direction perpendicular to the driving backboard, and conductive patterns located between every two adjacent device layers. Each of the plurality of device layers includes a first semiconductor pattern, a light emitting pattern, and a second semiconductor pattern stacked in a direction away from the driving backboard. The display panel is used for providing backlight or displaying images.

Description

Technical Field

[0001] The present disclosure relates to the field of display technologies, and in particular, to a light-emitting substrate, a preparation method thereof, and a display device. Background Art

[0002] With the development of Light-Emitting Diode (LED) technology, Micro Light Emitting Diode (Micro-LED) has been widely used. A Micro-LED refers to an LED chip with a size less than 100 μm. Micro-LED has good performance in terms of brightness, lifespan, contrast ratio, response time, energy consumption, viewing angle, and resolution, and has the advantages of self-luminescence, simple structure, small size, and energy saving, and is regarded as the next-generation display technology.

[0003] Related technologies provide a high-voltage light-emitting diode, including two or more light-emitting diodes, which are tiled on the same substrate and are connected in series by a bridging metal. However, two or more light-emitting diodes will occupy a relatively large area of the substrate, which is not conducive to reducing the size of pixels and improving the resolution of the display device. Summary of the Invention

[0004] An object of an embodiment of the present disclosure is to provide a light-emitting substrate, a preparation method thereof, and a display device, which are used to reduce the area of a high-voltage light-emitting diode and improve the pixel density of the light-emitting substrate.

[0005] To achieve the above object, the embodiments of the present disclosure provide the following technical solutions:

[0006] On the one hand, a light-emitting substrate is provided. The light-emitting substrate includes a driving backplane and a plurality of light-emitting devices disposed on the driving backplane. The driving backplane includes a plurality of driving circuits, and one light-emitting device is connected to one driving circuit. The light-emitting device includes a plurality of device layers stacked in a direction perpendicular to the driving backplane, and a conductive pattern located between two adjacent device layers. The plurality of device layers each include a first semiconductor pattern, a light-emitting pattern, and a second semiconductor pattern stacked in a direction away from the driving backplane.

[0007] The light-emitting substrate provided by the embodiments of the present disclosure. The light-emitting device includes a plurality of device layers, and each device layer includes a first semiconductor pattern, a light-emitting pattern, and a second semiconductor pattern stacked. In this way, each device layer can form a light-emitting diode, and the light-emitting device includes a plurality of light-emitting diodes, which are high-voltage light-emitting diodes. The plurality of device layers are stacked in a direction perpendicular to the driving backplane, that is, a plurality of light-emitting diodes are stacked in a direction perpendicular to the driving backplane. Compared with laying a plurality of device layers flat on the driving backplane, it can reduce the area of the driving backplane occupied by the light-emitting device, thereby reducing the size of the pixel, which is beneficial to increasing the setting density of the light-emitting device on the driving backplane, that is, increasing the arrangement density of the light-emitting devices on the light-emitting substrate, and further increasing the resolution of the display device.

[0008] In some embodiments, the light-emitting device further includes a first electrode and a second electrode. The first electrode is located on the side of the plurality of device layers close to the driving backplane, and is respectively connected to the driving backplane and the first semiconductor pattern closest to the driving backplane. The second electrode is located on the side of the plurality of device layers away from the driving backplane, and is connected to the second semiconductor pattern farthest from the driving backplane.

[0009] In some embodiments, the material of the first semiconductor pattern is a P-type semiconductor material, and the material of the second semiconductor pattern is an N-type semiconductor material.

[0010] In some embodiments, the light-emitting device further includes a current spreading pattern. The current spreading pattern is disposed between the first electrode and the first semiconductor pattern closest to the driving backplane.

[0011] In some embodiments, the material of the first semiconductor pattern includes an N-type semiconductor material, and the material of the second semiconductor pattern includes a P-type semiconductor material.

[0012] In some embodiments, the light-emitting device further includes a current spreading pattern, and the current spreading pattern is disposed between the second electrode and the second semiconductor pattern farthest from the driving backplane.

[0013] In some embodiments, the material of the conductive pattern includes a semiconductor material and doping ions. And the intrinsic semiconductor materials of the conductive pattern, the first semiconductor pattern, and the second semiconductor pattern are the same.

[0014] On the other hand, a display device is provided. The display device includes a driving circuit board and the light-emitting substrate in any of the above embodiments. The driving circuit board is connected to the light-emitting substrate, and the driving circuit board is configured to transmit a control signal to the light-emitting substrate.

[0015] The above display device has the same structure and beneficial technical effects as the light-emitting substrate provided in some of the above embodiments, and will not be described in detail herein.

[0016] In another aspect, a method for manufacturing a light-emitting substrate is also provided. The manufacturing method includes: growing an epitaxial layer on a substrate; sequentially forming a current spreading layer and a first electrode layer on the epitaxial layer; providing a first substrate and bonding the first substrate to the first electrode layer; removing the substrate to expose the epitaxial layer; patterning the epitaxial layer to form a plurality of spaced-apart light-emitting devices. Wherein, the epitaxial layer includes a plurality of stacked structures arranged in a stack, and a conductive layer located between any two adjacent stacked structures, and the stacked structure includes a first semiconductor layer, a light-emitting layer, and a second semiconductor layer arranged in a stack in a direction away from the substrate; one stacked structure of the epitaxial layer forms one device layer of the light-emitting device.

[0017] In some embodiments, the first substrate is a driving backplane, and the first substrate includes a plurality of driving circuits. The light-emitting device includes a first semiconductor pattern, a light-emitting pattern, and a second semiconductor pattern arranged in a stack in a direction away from the driving backplane, and the material of the first semiconductor pattern includes a P-type semiconductor material, and the material of the second semiconductor pattern includes an N-type semiconductor material.

[0018] In some embodiments, before bonding the first substrate to the first electrode layer, the manufacturing method further includes: patterning the first electrode layer to form a plurality of first electrodes. One first electrode is electrically connected to one driving circuit. Before patterning the epitaxial layer, the manufacturing method further includes: forming a plurality of second electrodes spaced apart on a side of the epitaxial layer away from the first substrate. One second electrode is configured to form a second electrode of one light-emitting device. After patterning the epitaxial layer, the manufacturing method further includes: patterning the current spreading layer to form a plurality of current spreading patterns. One of the current spreading patterns is connected to one first electrode.

[0019] In some embodiments, the material of the first electrode layer includes a metal material, and the material of the second electrode includes a transparent conductive material.

[0020] In some embodiments, after removing the substrate to expose the epitaxial layer and before patterning the epitaxial layer, the preparation method includes: forming a plurality of first electrodes distributed at intervals on a side of the epitaxial layer away from the first substrate; providing a driving backplane, bonding the driving backplane to the plurality of first electrodes; removing the first substrate to expose the first electrode layer; patterning the first electrode layer and the current spreading layer, the first electrode layer forming a plurality of second electrodes, and the current spreading layer forming a plurality of current spreading patterns; a positive projection of one of the second electrodes on the driving backplane at least partially coincides with a positive projection of one of the first electrodes on the driving backplane. The driving backplane includes a plurality of driving circuits, and one driving circuit is connected to one first electrode.

[0021] In some embodiments, the material of the first electrode layer includes a transparent conductive material, and the material of the first electrode includes a metal material.

[0022] In some embodiments, the material of the first semiconductor layer includes an N-type semiconductor material, and the second semiconductor material includes a P-type semiconductor material; and / or, the material of the conductive pattern includes a semiconductor material and doped ions, and the intrinsic semiconductor materials of the conductive pattern, the first semiconductor layer, and the second semiconductor layer are the same. Description of the Drawings

[0023] In order to more clearly illustrate the technical solutions in the present disclosure, the following will briefly introduce the drawings required in some embodiments of the present disclosure. Obviously, the drawings in the following description are only the drawings of some embodiments of the present disclosure. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings. In addition, the drawings in the following description can be regarded as schematic diagrams and do not limit the actual sizes of the products, the actual processes of the methods, the actual timings of the signals, etc. involved in the embodiments of the present disclosure.

[0024] Figure 1 Structural diagram of a display device according to some embodiments;

[0025] Figure 2 Structural diagram of a light-emitting substrate according to some embodiments;

[0026] Figure 3 Another structural diagram of a light-emitting substrate according to some embodiments;

[0027] Figure 4 Another structural diagram of a light-emitting substrate according to some embodiments;

[0028] Figure 5A Flowchart of a preparation method of a light-emitting substrate according to some embodiments;

[0029] Figure 5B Another flowchart of a method for preparing a light-emitting substrate according to some embodiments;

[0030] Figures 6 to 14 A process step diagram of a method for preparing a light-emitting substrate according to some embodiments;

[0031] Figures 15 to 22 Another process step diagram of a method for preparing a light-emitting substrate according to some embodiments. Detailed implementation manners

[0032] The technical solutions in some embodiments of the present disclosure will be clearly and completely described below with reference to the accompanying drawings. Apparently, the described embodiments are only a part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the embodiments provided by the present disclosure, all other embodiments obtained by those of ordinary skill in the art shall fall within the protection scope of the present disclosure.

[0033] Unless otherwise required by the context, throughout the specification and claims, the term "comprising" is interpreted in an open, inclusive sense, i.e., "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "examples" or "some examples", etc., are intended to indicate that specific features, structures, materials, or characteristics related to the embodiment or example are included in at least one embodiment or example of the present disclosure. The schematic representations of the above terms are not necessarily referring to the same embodiment or example. In addition, the specific features, structures, materials, or characteristics may be included in any one or more embodiments or examples in any appropriate manner.

[0034] Hereinafter, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the embodiments of the present disclosure, unless otherwise stated, the meaning of "a plurality" is two or more.

[0035] When describing some embodiments, the expressions "coupled" and "connected" and their derivatives may be used. The term "connected" should be understood in a broad sense. For example, "connected" may be a fixed connection, a detachable connection, or integrated; it may be directly connected or indirectly connected through an intermediate medium.

[0036] "At least one of A, B, and C" has the same meaning as "at least one of A, B, or C", and both include the following combinations of A, B, and C: only A, only B, only C, the combination of A and B, the combination of A and C, the combination of B and C, and the combination of A, B, and C.

[0037] "A and / or B" includes the following three combinations: only A, only B, and the combination of A and B.

[0038] As used herein, the use of "configured to" or "adapted to" means open and inclusive language, which does not exclude devices that are adapted to or configured to perform additional tasks or steps.

[0039] Additionally, the use of "based on" means open and inclusive because a process, step, calculation, or other action "based on" one or more of the stated conditions or values may in practice be based on additional conditions or values beyond those stated.

[0040] As used herein, "about", "substantially", or "approximately" includes the stated value and an average within an acceptable deviation range of the specific value, where the acceptable deviation range is determined by a person of ordinary skill in the art in view of the measurement being discussed and the errors associated with the measurement of a particular quantity (i.e., the limitations of the measurement system).

[0041] As used herein, "parallel", "perpendicular", "equal" include the stated situation and situations similar to the stated situation, where the range of the similar situations is within an acceptable deviation range, and the acceptable deviation range is determined by a person of ordinary skill in the art in view of the measurement being discussed and the errors associated with the measurement of a particular quantity (i.e., the limitations of the measurement system). For example, "parallel" includes absolute parallelism and approximate parallelism, where the acceptable deviation range for approximate parallelism can be, for example, within 5° deviation; "perpendicular" includes absolute perpendicularity and approximate perpendicularity, where the acceptable deviation range for approximate perpendicularity can also be, for example, within 5° deviation. "Equal" includes absolute equality and approximate equality, where the acceptable deviation range for approximate equality can be, for example, that the difference between the two equal values is less than or equal to 5% of either one.

[0042] It should be understood that when a layer or element is referred to as being on another layer or substrate, it can be that the layer or element is directly on the other layer or substrate, or there can be an intermediate layer between the layer or element and the other layer or substrate.

[0043] Exemplary embodiments are described herein with reference to cross-sectional views and / or plan views that are idealized exemplary drawings. In the drawings, the thickness of layers and the area of regions are enlarged for clarity. Accordingly, variations in the shape relative to the drawings due to, for example, manufacturing techniques and / or tolerances are contemplated. Thus, exemplary embodiments should not be construed as limited to the shapes of the regions shown herein, but include shape deviations resulting from, for example, manufacturing. For example, an etched region shown as rectangular will typically have curved features. Thus, the regions shown in the drawings are schematic in nature, and their shapes are not intended to depict the actual shape of the regions of the device and are not intended to limit the scope of the exemplary embodiments.

[0044] Embodiments of the present disclosure provide a display device 1000. Referring to Figure 1 , the display device 1000 can be any device that displays whether it is moving (e.g., video) or stationary (e.g., still image), and whether it is text or image.

[0045] Exemplarily, the display device 1000 can be a mobile phone, a wireless device, a personal digital assistant (PDA), a wearable device, an augmented reality (AR) device, a virtual reality (VR) device, a handheld or portable computer, a GPS receiver / navigator, a camera, an MP4 video player, a video camera, a game console, a watch, a clock, a calculator, a television monitor, a flat panel display, a computer monitor, an automotive display (e.g., an odometer display, etc.), a cockpit controller and / or display, a display of a camera view (e.g., a display of a rear view camera in a vehicle), an electronic photo, an electronic billboard or sign, a projector, a packaging and aesthetic structure (e.g., a display of an image of a piece of jewelry), etc. For example, as Figure 1 shown, the display device 1000 can be a mobile phone.

[0046] Referring to Figure 2 , the display device 1000 includes a light-emitting substrate 1100 and a driving circuit board (not shown in the figure). The driving circuit board is connected to the light-emitting substrate 1100 and is configured to transmit control signals to the light-emitting substrate 1100 to drive the light-emitting substrate 1100 to emit light. In addition, the display device 1000 can also include a touch structure, an under-screen camera, and an under-screen fingerprint recognition sensor, etc., so that the display device 1000 can implement various different functions such as touch control, photographing, video recording, fingerprint recognition, or face recognition. The structure of the display device 1000 is not limited thereto, as long as the same technical concept is adopted.

[0047] Continuing to refer to Figure 2, the light-emitting substrate 1100 may include a driving backplane 100 and a plurality of light-emitting devices 200 disposed on one side of the driving backplane 100.

[0048] In some embodiments, the driving backplane 100 may be, for example, the backplane in the backlight module of a liquid crystal display device (English: Liquid Crystal Display; abbreviation: LCD). At this time, the light-emitting substrate 1100 may serve as the backlight source in the LCD, and the display device further includes a liquid crystal display panel disposed on the light-emitting side of the light-emitting substrate. The light-emitting substrate 1100 is used to provide backlight for the liquid crystal display panel, and the liquid crystal display panel can adjust the intensity (gray scale) of the light passing through the liquid crystal display panel, thereby realizing image display. In other embodiments, the driving backplane 100 may be, for example, a display backplane. At this time, the light-emitting substrate 1100 can directly serve as an LED display device. The LED display device may be, for example, a Micro LED display device. That is to say, the light-emitting substrate 1100 can be used as a part of the backlight module of the liquid crystal display device or directly as the display screen of the display device.

[0049] Continue to refer to Figure 2 , the light-emitting device 200 includes a plurality of device layers 210 stacked in a direction perpendicular to the driving backplane 100, and a conductive pattern 220 located between any two adjacent device layers 210. The plurality of device layers 210 all include a direction Z away from the driving backplane 100 ( Figure 2The first semiconductor pattern 11, the light-emitting pattern 12, and the second semiconductor pattern 13 are stacked in the direction from bottom to top (in the Z direction away from the driving backplane 100). In other words, each device layer 210 includes the first semiconductor pattern 11, the light-emitting pattern 12, and the second semiconductor pattern 13 stacked in the Z direction away from the driving backplane 100. One device layer 210 is used to form one light-emitting diode. Two adjacent device layers 210 are connected by a conductive pattern 220. The multiple device layers 210 included in the same light-emitting device 200 are connected in series through the conductive pattern 220. In this way, the light-emitting device 200 includes multiple light-emitting diodes connected in series, and the light-emitting device 200 can form a high-voltage light-emitting diode. Compared with traditional light-emitting diodes, the high-voltage light-emitting diode has a higher driving voltage and a smaller driving current. Therefore, using high-voltage light-emitting diodes in the light-emitting substrate 1100 can reduce the power consumption of the light-emitting substrate 1100. The multiple device layers 210 are stacked in a direction perpendicular to the driving backplane 100, and the orthographic projections of the multiple device layers 210 on the driving backplane 100 coincide or substantially coincide. Compared with laying the multiple device layers included in the light-emitting device 200 flat on the driving backplane, the orthographic projection area of the light-emitting device 200 on the driving backplane 100 can be significantly reduced, that is, the area of the driving backplane 100 occupied by the light-emitting device 200 is reduced, which is beneficial to reducing the size of the light-emitting device 200, reducing the size of the pixel (each light-emitting device forms a pixel), increasing the arrangement density of the light-emitting devices 200 on the driving backplane 100, and further increasing the resolution of the display device formed by the light-emitting substrate 1100.

[0050] It should be noted that laying multiple device layers flat on the driving backplane means that the orthographic projections of the multiple device layers on the driving backplane do not coincide. That is to say, the multiple device layers are directly disposed on the driving backplane.

[0051] Exemplarily, the light-emitting device 200 may include two, three, or more device layers 210. In the drawings provided in the embodiments of the present disclosure, the light-emitting device 200 including two device layers 210 is taken as an example for display, but the embodiments of the present disclosure are not limited thereto, as long as the same technical idea is adopted.

[0052] In some embodiments, the material of the first semiconductor pattern 11 may be a P-type semiconductor material, and correspondingly, the material of the second semiconductor pattern 13 may be an N-type semiconductor material. Or, the material of the first semiconductor pattern 11 may be an N-type semiconductor material, and correspondingly, the material of the second semiconductor pattern 13 may be a P-type semiconductor material.

[0053] The materials of the first semiconductor pattern 11 and the second semiconductor pattern 13 include a variety of types and can be flexibly selected according to actual needs. Exemplarily, the intrinsic semiconductor materials in the first semiconductor pattern 11 and the second semiconductor pattern 13 are the same and can be any one of GaN, gallium phosphide (GaP), aluminum gallium arsenide (AlGaAs), and aluminum gallium indium phosphide (AlGaInP). The intrinsic semiconductor material of one of the first semiconductor pattern 11 and the second semiconductor pattern 13 is P-type doped to form a P-type semiconductor material, and the intrinsic semiconductor material of the other is N-type doped to form an N-type semiconductor material. A PN junction can be formed between the first semiconductor pattern 11 and the second semiconductor pattern 13. The light-emitting pattern 12 can be a multiple quantum well layer (English: Multiple Quantum Well; abbreviation: MQW). Exemplarily, the material of the light-emitting pattern 12 can be gallium nitride, and the intrinsic semiconductor materials of the first semiconductor pattern 11 and the second semiconductor pattern 13 are also gallium nitride.

[0054] It can be understood that when different voltages are applied to the first semiconductor pattern 11 and the second semiconductor pattern 13 of the device layer 210 respectively to form an electric field between the first semiconductor pattern 11 and the second semiconductor pattern 13, minority carriers and majority carriers can recombine in the light-emitting pattern 12 and release the excess energy in the form of light, thereby converting electrical energy into light energy. The materials of the light-emitting patterns 12 of the multiple light-emitting devices 200 included in the light-emitting substrate 1100 are the same. Based on this, the multiple light-emitting devices 200 can emit light of the same color. Exemplarily, the multiple light-emitting devices 200 all emit blue light. In this case, the display device can further include a color conversion layer (such as a quantum dot layer), and the color conversion layer is used to convert at least part of the blue light into light of other colors (such as red and green) so that the light-emitting substrate can perform color or full-color display.

[0055] The material of the conductive pattern 220 includes a semiconductor material and doped ions. That is to say, the conductive pattern 220 can be a heavily doped semiconductor material. Based on this, the conductive pattern 220 can also be formed by epitaxial growth, which is beneficial to simplifying the manufacturing difficulty of the light-emitting device 200 and reducing the manufacturing cost of the light-emitting substrate 1100. The intrinsic semiconductor materials of the conductive pattern 220, the first semiconductor pattern 11, and the second semiconductor pattern 13 can be the same, which is beneficial to improving the material identity of the light-emitting device 200 and further reducing the manufacturing difficulty of the light-emitting device 200. Exemplarily, in a specific example, the intrinsic semiconductor materials of the first semiconductor pattern 11, the light-emitting pattern 12, the second semiconductor pattern 13, and the conductive pattern 220 are all gallium nitride.

[0056] Continue to refer to Figure 2, the light-emitting device 200 further includes a first electrode 230 and a second electrode 240. The first electrode 230 is located on the side of the plurality of device layers 210 close to the driving backplane 100, and is respectively connected to the driving backplane 100 (the driving circuit of the driving backplane 100) and the first semiconductor pattern 11 closest to the driving backplane 100. The first electrode 230 is used to transmit an electrical signal to the first semiconductor pattern 11, such as applying a voltage to the first semiconductor pattern 11.

[0057] In some embodiments, the material of the first electrode 230 includes a metal material. Exemplarily, the first electrode 230 may be a metal stack structure, and the metal stack structure may include a gold layer (Au), a nickel layer (Ni), an aluminum layer (Al), and a titanium layer (Ti) stacked in the direction Z away from the driving backplane 100; alternatively, the metal stack structure includes a gold layer, a platinum layer, and a chromium layer stacked in sequence in the direction Z away from the driving backplane 100. The metal stack structure can form an ohmic contact with the first semiconductor pattern 11, which is beneficial to reducing the contact resistance between the first electrode 230 and the first semiconductor pattern 11. Moreover, since the first electrode 230 is made of a metal material, the light emitted by the device layer 210 toward the side close to the driving backplane 100 can be reflected on the surface of the first electrode 230 after hitting the first electrode 230 and then emitted in the direction away from the driving backplane 100, which is beneficial to improving the light-emitting efficiency of the light-emitting device 200.

[0058] The second electrode 240 is located on the side of the plurality of device layers 210 away from the driving backplane 100, and is connected to the second semiconductor pattern 13 farthest from the driving backplane 100. The second electrode 240 is used to transmit an electrical signal to the second semiconductor pattern 13, such as the second electrode 240 is used to apply a voltage signal to the second semiconductor pattern 13.

[0059] The material of the second electrode 240 includes a transparent conductive material so that light can pass through the second electrode 240 and be emitted in the direction away from the driving backplane 100. It can be understood that the transparent conductive material refers to a material with a light transmittance greater than a preset value (such as 80%, 90%, or 95%, etc.). Exemplarily, the material of the second electrode 240 may be indium tin oxide (English: Indium Tin Oxide; abbreviation: ITO) or indium zinc oxide (English: Indium Zinc Oxide; abbreviation: IZO), etc.

[0060] In some embodiments, refer to Figure 2, the light-emitting device 200 further includes a current spreading pattern 250. When the material of the first semiconductor pattern 11 is a P-type semiconductor material and the material of the second semiconductor pattern 13 is an N-type semiconductor material, the current spreading pattern 250 is disposed between the first electrode 230 and the first semiconductor pattern 11 closest to the driving backplane 100 (the lowermost first semiconductor pattern 11). The current spreading pattern 250 is used to improve current spreadability, enhance the current spreading effect, and thus improve the light-emitting efficiency of the light-emitting device. Exemplarily, the material of the current spreading pattern 250 may include indium tin oxide and / or indium zinc oxide.

[0061] In some other embodiments, refer to Figure 3 , the light-emitting device 200 further includes a current spreading pattern 250. When the material of the first semiconductor pattern 11 is an N-type semiconductor material and the material of the second semiconductor pattern 13 is a P-type semiconductor material, the current spreading pattern 250 is disposed between the second electrode 240 and the second semiconductor pattern 13 farthest from the driving backplane 100 (the uppermost second semiconductor pattern 13). The current spreading pattern 250 is used to improve current spreadability, enhance the current spreading effect, and thus improve the light-emitting efficiency of the light-emitting device. Exemplarily, the material of the current spreading pattern 250 may include indium tin oxide and / or indium zinc oxide.

[0062] In some embodiments, refer to Figure 4 , the light-emitting substrate 1100 further includes an insulating layer 300 and a reflective layer 400. The insulating layer 300 covers the sidewalls of the light-emitting device 200. The insulating layer 300 is used to protect the sidewalls of the light-emitting device 200 and separate the reflective layer 400 from the light-emitting device 200, especially separating the conductive film layers in the light-emitting device 200 from the reflective layer 400, reducing the risk of the reflective layer 400 electrically connecting adjacent light-emitting devices 200. The reflective layer 400 is used to reflect the light emitted by the light-emitting device 200, so that as much light as possible emitted by the light-emitting device 200 is emitted in the direction Z away from the driving backplane 100, improving the light extraction efficiency of the light-emitting substrate 1100. At the same time, the reflective layer 400 can reduce the light from hitting adjacent light-emitting devices 200 and reduce the risk of light mixing (optical crosstalk) between adjacent light-emitting devices 200.

[0063] Exemplarily, the material of the insulating layer 300 may include an insulating material, the insulating material may be silicon oxide, and the thickness of the insulating layer may be 500 nm to 1000 nm. Exemplarily, the thickness of the insulating layer 300 may be 500 nm, 750 nm, 900 nm, or 1000 nm, etc. However, the material and thickness of the insulating layer 300 are not limited thereto, as long as the same technical idea is adopted.

[0064] Exemplarily, the material of the reflective layer 400 can be a metal reflective material. For example, the material of the reflective layer 400 can include materials with high reflectivity such as silver or aluminum. Of course, the material of the reflective layer 400 can also be other materials with high reflectivity, as long as the same technical concept is adopted. The thickness of the reflective layer 400 is 50 nm to 150 nm. Exemplarily, the thickness of the reflective layer 400 can be 50 nm, 70 nm, 110 nm, 125 nm, or 150 nm, etc., and will not be listed one by one here.

[0065] In some embodiments, as Figure 4 shown, the light-emitting substrate 1100 further includes a bonding adhesive 260, and the bonding adhesive 260 is used to bond and connect the light-emitting device 200 to the driving backplane 100. Of course, the structure of the light-emitting substrate 1100 is not limited thereto, as long as the same technical concept is adopted.

[0066] Continuing to refer to Figure 4 , the light-emitting substrate 1100 may further include a bonding adhesive 260, and the bonding adhesive 260 is used to bond and connect the light-emitting device 200 to the driving backplane 100.

[0067] Some other embodiments of the present disclosure further provide a method for preparing a light-emitting substrate. Referring to Figure 5A and Figure 5B , the preparation method includes S100 to S600.

[0068] S100, referring to Figure 6 , grow an epitaxial layer 600 on the substrate 500.

[0069] In some embodiments, the substrate 500 may include a substrate 510 and a buffer layer 520 disposed on the substrate 510. The substrate 510 can be a silicon substrate (Si), a sapphire substrate (aluminum oxide Al 2 0 3 ), a silicon carbide substrate (SiC), gallium arsenide (GaAs), aluminum nitride (AlN), or zinc oxide (ZnO).

[0070] The epitaxial layer 600 includes a plurality of stacked structures 610 stacked on top of each other, and a conductive layer 620 located between any two adjacent stacked structures 610. The stacked structure 610 includes a first semiconductor layer 611, a light-emitting layer 612, and a second semiconductor layer 613 stacked in a direction away from the substrate 500. Exemplarily, the material of the first semiconductor layer 611 is an N-type semiconductor material, and the material of the second semiconductor layer 613 is a P-type semiconductor material. The material of the conductive layer 620 includes a semiconductor material and doping ions.

[0071] Exemplarily, an epitaxial process can be used to sequentially grow a buffer layer 520, a first semiconductor layer 611, a light-emitting layer 612, a second semiconductor layer 613, and a conductive layer 620 on a substrate 510. Among them, the substrate 500 and the epitaxial layer 600 together can be referred to as an epitaxial wafer.

[0072] S200, refer to Figure 7 , and a current spreading layer 251 and a first electrode layer 231 are sequentially formed on the epitaxial layer 600.

[0073] The material of the current spreading layer 251 can include indium tin oxide and / or indium zinc oxide. The current spreading layer 251 and the first electrode layer 231 can be formed by using electron beam evaporation technology or magnetron sputtering technology.

[0074] The above-mentioned first semiconductor layer 611 can be used to form the first semiconductor pattern 11 or the second semiconductor pattern 13 of the light-emitting device 200. When the first semiconductor layer 611 is used to form the first semiconductor pattern 11, the first electrode layer 231 is used to form the first electrode 230. At this time, the material of the first electrode layer 231 includes a metal material. For example, the first electrode layer 231 can be a metal stack structure, and the metal stack structure is referred to above and will not be elaborated here. When the first semiconductor layer 611 is used to form the second semiconductor pattern 13, the first electrode layer 231 is used to form the second electrode 240. At this time, the material of the first electrode layer 231 includes a transparent conductive material (such as ITO / IZO, etc.).

[0075] Hereinafter, taking the case where the first semiconductor layer 611 can be used to form the first semiconductor pattern 11 and the second semiconductor pattern 13 of the light-emitting device 200 as examples respectively, an exemplary description will be given of the method for preparing the light-emitting substrate according to the embodiments of the present disclosure.

[0076] When the first semiconductor layer 611 is used to form the first semiconductor pattern 11 and the first electrode layer 231 is used to form the first electrode 230, as Figure 5A shown, after the current spreading layer 251 and the first electrode layer 231 are sequentially formed on the epitaxial layer 600 in the above step S200, the preparation method further includes S210.

[0077] S210, refer to Figure 8 , pattern the first electrode layer 231 to form a plurality of first electrodes 230.

[0078] Exemplarily, a dry or wet etching process can be used to etch the first electrode layer 231 to remove part of the first electrode layer 231, and a plurality of first electrodes 230 arranged in an array are formed.

[0079] S300, refer to Figure 9, provide the first substrate 110, and bond the first substrate 110 to the first electrode layer 231 (multiple first electrodes 230).

[0080] Exemplarily, when the first electrode layer 231 is used to form the first electrodes 230, the first substrate 110 may be a driving backplane 100, and the driving backplane 100 includes multiple driving circuits. At this time, after the first electrode layer 231 is patterned through the above step S210, multiple first electrodes 230 are formed, and each first electrode 230 is electrically connected to one driving circuit of the driving backplane 100.

[0081] Exemplarily, the first substrate 110 and the multiple first electrodes 230 are bonded through a high-precision alignment bonding process. The film layer on the first substrate 110 bonded to the first electrodes 230 may be a metal film layer, such as a tin layer or a gold layer, etc.

[0082] S400, refer to Figure 10 , remove the substrate 500 to expose the epitaxial layer 600.

[0083] Exemplarily, when the substrate 510 is a sapphire substrate, the sapphire substrate can be peeled off by using the laser lift-off technology (English: Laser Lift-off; abbreviation: LLO). When the substrate 510 is a silicon substrate, the thickness of the substrate 510 can be thinned first by using the chemical-mechanical polishing process (English: Chemical-Mechanical Polishing; abbreviation: CMP), and then the remaining substrate 510 can be removed by using the wet etching process. The buffer layer 520 can be removed by using the ICP etching technology, and the etching gas can include chlorine gas (Cl2) and boron trichloride (BCl3).

[0084] In some embodiments, the first semiconductor layer 611 is used to form the first semiconductor pattern 11, and the first electrode layer 231 is used to form the first electrodes 230. As Figure 5A shown, after removing the substrate 500 to expose the epitaxial layer 600 in the above step S400, the preparation method further includes S410.

[0085] S410, refer to Figure 11 , form multiple second electrodes 240 distributed at intervals on the side of the epitaxial layer 600 away from the first substrate 110.

[0086] Exemplarily, a continuous and integral second electrode layer may be first formed on the epitaxial layer 600, and then the integral second electrode layer is patterned so that the second electrode layer forms a plurality of second electrodes 240 distributed at intervals. The material of the second electrode layer is a transparent conductive material, and processes such as evaporation or sputtering can be used for preparation, and the second electrode layer can be patterned by dry or wet etching processes. Of course, the preparation method of the second electrode 240 is not limited to this, as long as the same technical concept is adopted.

[0087] S500, refer to Figure 11 and Figure 12 , pattern the epitaxial layer 600 so that the epitaxial layer 600 forms a plurality of light-emitting devices 200 distributed at intervals, wherein a stacked structure 610 of the epitaxial layer 600 forms a device layer 210 of the light-emitting device 200.

[0088] Exemplarily, the epitaxial layer 600 can be etched by dry etching or wet etching processes to remove a part of the epitaxial layer 600 so that the epitaxial layer 600 forms a plurality of light-emitting devices 200. The second semiconductor layer 613 in the stacked structure 610 forms the first semiconductor pattern 11 in the device layer 210, and the first semiconductor layer 611 forms the second semiconductor pattern 13 in the device layer 210. When the first semiconductor layer 611 is prepared with an N-type semiconductor material and the second semiconductor layer is prepared with a P-type semiconductor material, the material of the first semiconductor pattern 11 is a P-type semiconductor material, and the material of the second semiconductor pattern 13 is an N-type semiconductor material.

[0089] In some embodiments, after the above step S500, the preparation method further includes S510.

[0090] S510, refer to Figure 13 , pattern the current spreading layer 251 to divide the current spreading layer 251 into a plurality of current spreading patterns 250, and one current spreading pattern 250 is connected to one first electrode 230.

[0091] S600, refer to Figure 14 , sequentially deposit an insulating layer 300 and a reflective layer 400 on the sidewalls of the light-emitting device 200.

[0092] The insulating layer 300 covers the sidewalls of the light-emitting device 200. The insulating layer 300 is used to protect the sidewalls of the light-emitting device 200 and separate the reflective layer 400 from the light-emitting device 200. In particular, it separates the conductive film layers in the light-emitting device 200 from the reflective layer 400, reducing the risk of the reflective layer 400 electrically connecting adjacent light-emitting devices 200. The reflective layer 400 is used to reflect the light emitted by the light-emitting device 200, so that as much light as possible emitted by the light-emitting device 200 is emitted in a direction away from the driving backplane, improving the light extraction efficiency of the light-emitting substrate 1100. At the same time, the reflective layer 400 can reduce the light from hitting adjacent light-emitting devices 200, reducing the risk of light mixing (optical crosstalk) between adjacent light-emitting devices 200.

[0093] The insulating layer 300 and the reflective layer 400 can also cover the portion of the bonding glue 260 located between adjacent light-emitting devices 200, which can reduce the light from the side of the driving backplane 100 away from the light-emitting device 200 and shoot towards the light extraction side of the light-emitting substrate along the direction Z close to the driving backplane, reducing the interference of external light on the light-emitting substrate.

[0094] In the case where the first semiconductor layer 611 is used to form the second semiconductor pattern 13 and the first electrode layer 231 is used to form the second electrode 240, as Figure 5B shown, after the current spreading layer 251 and the first electrode layer 231 are sequentially formed on the epitaxial layer 600 in the above step S200, the manufacturing method further includes S300.

[0095] S300, refer to Figure 15 , provide a first substrate 110 and bond the first substrate 110 to the first electrode layer 231.

[0096] The first substrate 110 can be a transfer substrate, and no circuit structure is provided on the first substrate 110. The first electrode layer 231 can be bonded to the first substrate 110 without patterning treatment. The first substrate 110 can be a glass substrate, a sapphire substrate, a silicon substrate, or any other suitable substrate.

[0097] S400, refer to Figure 16 , remove the substrate 500 to expose the epitaxial layer 600.

[0098] Exemplarily, the substrate 500 includes a base 510 and a buffer layer 520. When the base 510 is a sapphire substrate, the sapphire substrate can be peeled off by using the Laser Lift-off (LLO) technology. When the base 510 is a silicon substrate, the thickness of the base 510 can be thinned first by using the Chemical-Mechanical Polishing (CMP) process, and then the remaining base 510 can be removed by using a wet etching process. The buffer layer 520 can be removed by using the ICP etching technology, and the etching gas can include chlorine gas (Cl2) and boron trichloride (BCl3).

[0099] In some embodiments, when the first semiconductor layer 611 is used to form the second semiconductor pattern 13 and the first electrode layer 231 is used to form the second electrode 240, as Figure 5B shown, after removing the substrate 500 in the above step S400 and exposing the epitaxial layer 600, and before patterning the epitaxial layer 600 in S500, the preparation method further includes S420 to S450.

[0100] S420, referring to Figure 17 , a plurality of first electrodes 230 are formed at intervals on the side of the epitaxial layer 600 away from the first substrate 110.

[0101] Exemplarily, a continuous and integral third electrode layer can be formed on the epitaxial layer 600 first, and then the entire third electrode layer is patterned so that the third electrode layer forms a plurality of spaced-apart first electrodes 230. The material of the second electrode layer includes a metal material. Exemplarily, the second electrode layer can be a metal stack structure, and the metal stack structure is referred to above and will not be elaborated here. Exemplarily, it can be prepared by processes such as evaporation or sputtering, and the second electrode layer can be patterned by a dry or wet etching process. Of course, the preparation method of the second electrode 240 is not limited to this. For example, a plurality of first electrodes 230 can also be prepared by using the Metal Lift-Off Technology, as long as the same technical idea is adopted.

[0102] S430, referring to Figure 18 , a driving backplane 100 is provided, and the driving backplane 100 is bonded to the plurality of first electrodes 230.

[0103] The driving backplane 100 includes a plurality of driving circuits, and one driving circuit is connected to one first electrode 230. Exemplarily, the driving backplane 100 and the plurality of first electrodes 230 are bonded by a high-precision alignment bonding process. The film layer on the driving backplane 100 bonded to the first electrode 230 can be a metal film layer, such as a tin layer or a gold layer, etc.

[0104] S440, refer to Figure 19 , remove the first substrate 110 to expose the first electrode layer 231.

[0105] Exemplarily, the appropriate process can be selected to remove the first substrate 110 according to the material of the first substrate 110. Exemplarily, at least one of an etching process, a grinding process (English: Chemical-Mechanical Polishing; abbreviation: CMP), or a mechanical peeling process can be used to remove the first substrate 110.

[0106] S450, refer to Figure 20 , pattern the first electrode layer 231 and the current spreading layer 251, the first electrode layer 231 forms a plurality of second electrodes 240, and the current spreading layer 251 forms a plurality of current spreading patterns 250.

[0107] Exemplarily, a dry etching or a wet etching process can be used to pattern the first electrode layer 231 and the current spreading layer 251.

[0108] S500, refer to Figure 21 , pattern the epitaxial layer 600 so that the epitaxial layer 600 forms a plurality of spaced-apart light-emitting devices 200, wherein one stacked structure 610 of the epitaxial layer 600 forms one device layer 210 of the light-emitting device 200.

[0109] Exemplarily, a dry etching or a wet etching process can be used to etch the epitaxial layer 600, remove a part of the epitaxial layer 600 so that the epitaxial layer 600 forms a plurality of light-emitting devices 200. The first semiconductor layer 611 in the stacked structure 610 forms the first semiconductor pattern 11 in the device layer 210, and the second semiconductor layer 613 forms the second semiconductor pattern 13 in the device layer 210. When the first semiconductor layer 611 is prepared with an N-type semiconductor material and the second semiconductor layer is a P-type semiconductor material, the material of the first semiconductor pattern 11 is an N-type semiconductor material, and the material of the second semiconductor pattern 13 is a P-type semiconductor material.

[0110] S600, refer to Figure 22 , sequentially deposit an insulating layer 300 and a reflective layer 400 on the sidewalls of the light-emitting device 200.

[0111] For the structures and preparation processes of the insulating layer 300 and the reflective layer 400, refer to the above, and details are not described herein again.

[0112] As described above, it is only the specific implementation manner of the present disclosure. However, the protection scope of the present disclosure is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present disclosure who contemplates changes or substitutions should be covered within the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure shall be subject to the protection scope of the claims described above.

Claims

1. A light-emitting substrate, characterized in that, it comprises: a driving backplane including a plurality of driving circuits; a plurality of light-emitting devices disposed on one side of the driving backplane, and one light-emitting device is connected to one driving circuit; the light-emitting device includes a plurality of device layers stacked in a direction perpendicular to the driving backplane, and a conductive pattern located between any two adjacent device layers, and the plurality of device layers each include a first semiconductor pattern, a light-emitting pattern, and a second semiconductor pattern stacked in a direction away from the driving backplane.

2. The light-emitting substrate according to claim 1, characterized in that, the light-emitting device further comprises: a first electrode located on the side of the plurality of device layers close to the driving backplane, and connected to the driving backplane and the first semiconductor pattern closest to the driving backplane respectively; a second electrode located on the side of the plurality of device layers away from the driving backplane, and connected to the second semiconductor pattern farthest from the driving backplane.

3. The light-emitting substrate according to claim 2, characterized in that, the material of the first semiconductor pattern is a P-type semiconductor material, and the material of the second semiconductor pattern is an N-type semiconductor material.

4. The light-emitting substrate according to claim 3, characterized in that, the light-emitting device further comprises: a current spreading pattern disposed between the first electrode and the first semiconductor pattern closest to the driving backplane.

5. The light-emitting substrate according to claim 2, characterized in that, the material of the first semiconductor pattern includes an N-type semiconductor material, and the material of the second semiconductor pattern includes a P-type semiconductor material.

6. The light-emitting substrate according to claim 5, characterized in that, the light-emitting device further comprises: a current spreading pattern disposed between the second electrode and the second semiconductor pattern farthest from the driving backplane.

7. The light-emitting substrate according to any one of claims 1 to 6, characterized in that, the material of the conductive pattern includes a semiconductor material and doping ions; and the intrinsic semiconductor materials of the conductive pattern, the first semiconductor pattern, and the second semiconductor pattern are the same.

8. A display device, characterized in that, it comprises: a light-emitting substrate according to any one of claims 1 to 7; a driving circuit board connected to the light-emitting substrate and configured to transmit control signals to the light-emitting substrate.

9. A method for manufacturing a light-emitting substrate, characterized in that, it comprises: growing an epitaxial layer on a substrate; the epitaxial layer includes a plurality of stacked structures stacked, and a conductive layer located between any two adjacent stacked structures, and the stacked structure includes a first semiconductor layer, a light-emitting layer, and a second semiconductor layer stacked in a direction away from the substrate; successively forming a current spreading layer and a first electrode layer on the epitaxial layer; providing a first substrate and bonding the first substrate to the first electrode layer; removing the substrate to expose the epitaxial layer; patterning the epitaxial layer to form a plurality of spaced-apart light-emitting devices; wherein, one stacked structure of the epitaxial layer forms one device layer of the light-emitting device.

10. The manufacturing method according to claim 9, characterized in that, The first substrate is a driving backplane, and the first substrate includes a plurality of driving circuits; The light-emitting device includes a first semiconductor pattern, a light-emitting pattern, and a second semiconductor pattern stacked in a direction away from the driving backplane, and the material of the first semiconductor pattern includes a P-type semiconductor material, and the material of the second semiconductor pattern includes an N-type semiconductor material.

11. The manufacturing method according to claim 10, characterized in that, Before bonding the first substrate and the first electrode layer, the manufacturing method further includes: Patterning the first electrode layer to form a plurality of first electrodes; one first electrode is electrically connected to one driving circuit; Before patterning the epitaxial layer, the manufacturing method further includes: Forming a plurality of second electrodes distributed at intervals on a side of the epitaxial layer away from the first substrate; one second electrode is configured to form a second electrode of one light-emitting device; After patterning the epitaxial layer, the manufacturing method further includes: Patterning the current spreading layer to form a plurality of current spreading patterns; one current spreading pattern is connected to one first electrode.

12. The manufacturing method according to claim 11, characterized in that, The material of the first electrode layer includes a metal material, and the material of the second electrode includes a transparent conductive material.

13. The manufacturing method according to claim 9, characterized in that, After removing the substrate to expose the epitaxial layer and before patterning the epitaxial layer, the manufacturing method includes: Forming a plurality of first electrodes distributed at intervals on a side of the epitaxial layer away from the first substrate; Providing a driving backplane, and bonding the driving backplane to the plurality of first electrodes; the driving backplane includes a plurality of driving circuits, and one driving circuit is connected to one first electrode; Removing the first substrate to expose the first electrode layer; Patterning the first electrode layer and the current spreading layer, the first electrode layer forms a plurality of second electrodes, and the current spreading layer forms a plurality of current spreading patterns.

14. The manufacturing method according to claim 13, characterized in that, The material of the first electrode layer includes a transparent conductive material, and the material of the first electrode includes a metal material.

15. The manufacturing method according to any one of claims 9 to 14, characterized in that, The material of the first semiconductor layer includes an N-type semiconductor material, and the second semiconductor material includes a P-type semiconductor material; and / or, The material of the conductive pattern includes a semiconductor material and doping ions, and the intrinsic semiconductor materials of the conductive pattern, the first semiconductor layer, and the second semiconductor layer are the same.

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