Display substrate, preparation method thereof and display device

Abstract

The invention provides a display substrate, a preparation method thereof and a display device, and belongs to the technical field of display. The display substrate disclosed by the invention comprises a substrate base plate; the plurality of pixel units are arranged on the substrate, each pixel unit comprises a plurality of sub-pixels, each sub-pixel comprises a pixel driving circuit, a light-emitting chip, a first bonding pad and a second bonding pad, and the first bonding pad is connected with the pixel driving circuit; a first pole of the light-emitting chip is configured to be connected with the first bonding pad, and a second pole of the light-emitting chip is configured to be connected with the second bonding pad; wherein at least part of sub-pixels, which can be lightened, in the pixel units serve as display sub-pixels, and the remaining sub-pixels serve as redundant sub-pixels; a color conversion layer is arranged on the light-emitting side of the light-emitting chips of at least part of the display sub-pixels; and the number of the display sub-pixels in the pixel units is greater than the number of the redundant sub-pixels.

Description

Display substrate, preparation method thereof and display device TECHNICAL FIELD

[0001] The present disclosure belongs to the technical field of display, and particularly relates to a display substrate, a preparation method thereof and a display device. BACKGROUND

[0002] With the development of the display technical field, a mini Light-Emitting Diode (LED) display substrate has the advantages of high color purity, wide dynamic range, high brightness, high definition, low working voltage, small power consumption, long service life, impact resistance, large viewing angle and stable and reliable working, etc. The LED display substrate will become the most advantageous new generation of display media, wherein the LED display substrate comprises a plurality of LED light emitting chips arranged in an array. The research and development of the LED light emitting chips, especially the mini-LED and micro-LED light emitting chips, has become an important issue in the display field.

[0003] SUMMARY

[0004] The present disclosure aims to at least solve one of the technical problems existing in the prior art, and provides a display substrate, a preparation method thereof and a display device.

[0005] The present disclosure provides a display substrate, comprising:

[0006] a substrate substrate;

[0007] a plurality of pixel units arranged on the substrate substrate, wherein each pixel unit comprises a plurality of sub-pixels, and each sub-pixel comprises a pixel driving circuit, a light emitting chip, a first pad and a second pad, the first pad is connected with the pixel driving circuit, the first pole of the light emitting chip is configured to be connected with the first pad, and the second pole of the light emitting chip is configured to be connected with the second pad; and

[0008] at least part of the sub-pixels in each pixel unit can be lighted, and the lighted sub-pixels are used as display sub-pixels, and the remaining sub-pixels are used as redundant sub-pixels; the light emitting chip of at least part of the display sub-pixels is provided with a color conversion layer on the light emitting side; and the number of the display sub-pixels in each pixel unit is greater than the number of the redundant sub-pixels.

[0009] In some examples, the light emitting chip of the sub-pixel capable of emitting light in the redundant sub-pixel is provided with a light shielding pattern or a reflective layer on the light emitting side.

[0010] In some examples, the light emitting chip is configured to emit light of a first color, the display sub-pixel includes a first sub-pixel, a second sub-pixel and a third sub-pixel; the color conversion layer includes a first color conversion pattern arranged on the light emitting side of the light emitting chip of the first sub-pixel, and a second color conversion pattern arranged on the light emitting side of the light emitting chip of the second sub-pixel; wherein,

[0011] The first color conversion pattern is configured to emit light of a second color under excitation of the light of the first color; and the second color conversion pattern is configured to emit light of a third color under excitation of the light of the first color.

[0012] In some examples, a distributed Bragg reflector is arranged on the light emitting side of the first color conversion pattern and the second color conversion pattern; the reflectivity of the distributed Bragg reflector to the light of the second color and the light of the third color is less than the reflectivity of the distributed Bragg reflector to the light of the first color; and the transmittance of the distributed Bragg reflector to the light of the second color and the light of the third color is greater than the transmittance of the distributed Bragg reflector to the light of the first color.

[0013] In some examples, a color resistance of the second color is arranged on the light emitting side of the first color conversion pattern, and a color resistance of the third color is arranged on the light emitting side of the second color conversion pattern.

[0014] In some examples, a semi-transmissive and semi-reflective film layer is arranged on the light emitting side of the first color conversion pattern and the second color conversion pattern, and is configured to transmit a part of the light emitted by the light emitting chip and reflect another part of the light.

[0015] In some examples, the material of the color conversion layer includes quantum dots or fluorescent powder.

[0016] In some examples, the sub-pixels in the pixel unit are arranged side by side;

[0017] Alternatively,

[0018] The number of sub-pixels in the pixel unit is four, and the four sub-pixels are arranged in an array.

[0019] Alternatively,

[0020] The number of sub-pixels in the pixel unit is five, one of the five sub-pixels is surrounded by the other four sub-pixels, and the four sub-pixels are arranged in an array.

[0021] In some examples, the light emitting chip is a Micro-LED light emitting chip or a Mini-LED light emitting chip.

[0022] This disclosure provides a display device comprising any of the display substrates described above.

[0023] This disclosure provides a method for preparing a display substrate, comprising:

[0024] Provide a substrate;

[0025] Multiple pixel units are formed on the substrate. Each pixel unit includes multiple sub-pixels. Each sub-pixel includes a pixel driving circuit, a light-emitting chip, a first pad, and a second pad. The first pad is connected to the pixel driving circuit. The first electrode of the light-emitting chip is configured to be connected to the first pad, and the second electrode of the light-emitting chip is configured to be connected to the second pad.

[0026] Detect whether the sub-pixels of each pixel unit can be lit, and take at least some of the sub-pixels in the pixel unit that can be lit as display sub-pixels, and take the remaining sub-pixels as redundant sub-pixels;

[0027] A color conversion layer is formed based on the position information of the displayed sub-pixels.

[0028] In some examples, the preparation method further includes:

[0029] Determine the position information of the sub-pixels that can emit light among the redundant sub-pixels;

[0030] A light-shielding pattern or a reflective layer is formed on the light-emitting side of the light-emitting chip of the light-emitting sub-pixel in the redundant sub-pixels.

[0031] In some examples, the light-emitting chip is configured to emit light of a first color, and the display sub-pixel includes a first sub-pixel, a second sub-pixel, and a third sub-pixel; the color conversion layer includes forming a first color conversion pattern on the light-emitting side of the light-emitting chip of the first sub-pixel, and forming a second color conversion pattern on the light-emitting side of the light-emitting chip of the second sub-pixel; wherein,

[0032] The first color conversion pattern is configured to emit light of a second color when excited by light of the first color; the second color conversion pattern is configured to emit light of a third color when excited by light of the first color.

[0033] In some examples, the fabrication method further includes forming a distributed Bragg mirror on the light-emitting side of the first color conversion pattern and the second color conversion pattern; the reflectivity of the distributed Bragg mirror for light of the second color and light of the third color is less than the reflectivity for light of the first color; and the transmittance of the distributed Bragg mirror for light of the second color and light of the third color is greater than the transmittance for light of the first color.

[0034] In some examples, the preparation method further comprises forming a color resist of a second color on the light-out side of the first color conversion pattern, and forming a color resist of a third color on the light-out side of the second color conversion pattern.

[0035] In some examples, the preparation method further comprises forming a semi-transmissive and semi-reflective film layer on the light-out side of the first color conversion pattern and the second color conversion pattern, configured to transmit a part of the light emitted by the light-emitting chip and reflect another part.

[0036] In some examples, the step of forming the color conversion layer according to the position information of the display sub-pixels comprises:

[0037] According to the position information of the display sub-pixels, the color conversion layer is directly formed on the light-out side of the light-emitting chip, or is attached to the light-out side of the light-emitting chip in a manner of attachment.

[0038] In some examples, the number of the redundant sub-pixels in the pixel unit is less than the number of the display sub-pixels.

[0039] In some examples, the number of the display sub-pixels in the pixel unit is 3, and the number of the redundant sub-pixels is 1; or the number of the display sub-pixels in the pixel unit is 3, and the number of the redundant sub-pixels is 2.

[0040] In some examples, the material of the color conversion layer comprises quantum dots or fluorescent powder. BRIEF DESCRIPTION OF DRAWINGS

[0041] FIG. 1 is a cross-sectional view of an exemplary light-emitting chip.

[0042] FIG. 2 is a schematic view of a display substrate according to an embodiment of the present disclosure.

[0043] FIG. 3 is a correspondence between display sub-pixels and a color conversion layer under a first exemplary pixel arrangement according to an embodiment of the present disclosure.

[0044] FIG. 4 is a correspondence between display sub-pixels and a color conversion layer under a second exemplary pixel arrangement according to an embodiment of the present disclosure.

[0045] FIG. 5 is a correspondence between display sub-pixels and a color conversion layer under a third exemplary pixel arrangement according to an embodiment of the present disclosure.

[0046] FIG. 6 is a correspondence between display sub-pixels and a color conversion layer under a fourth exemplary pixel arrangement according to an embodiment of the present disclosure.

[0047] FIG. 7 is a schematic view of an exemplary display substrate according to an embodiment of the present disclosure.

[0048] FIG. 8 is a schematic view of another exemplary display substrate according to embodiments of the present disclosure.

[0049] FIG. 9 is a schematic view of still another exemplary display substrate according to embodiments of the present disclosure.

[0050] FIG. 10 is a partial flowchart of a method of manufacturing a display substrate according to embodiments of the present disclosure. DETAILED DESCRIPTION

[0051] For those skilled in the art to better understand the technical solutions of the present application, the present application will be described in further detail below in conjunction with the drawings and specific embodiments.

[0052] Unless otherwise defined, technical terms or scientific terms used in the present disclosure shall have the ordinary meaning understood by those skilled in the art to which the present disclosure pertains. The terms "first", "second", and similar terms used in the present disclosure do not denote any order, quantity, or importance, but are used to distinguish different components. Similarly, the terms "one", "a", or "the" and similar terms do not denote a quantity restriction, but mean that at least one exists. The terms "include", "comprise", and similar terms mean that the elements or objects before the terms encompass the elements or objects listed after the terms and their equivalents, and do not exclude other elements or objects. The terms "connected" or "connected" and similar terms do not mean physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms "up", "down", "left", "right", and the like are used only to indicate relative positional relationships, and when the absolute positions of the described objects change, the relative positional relationships can also change accordingly.

[0053] Currently, among the three colors of red, green, and blue LED light emitting chips, the blue LED light emitting chip has the highest light emitting efficiency and the lowest cost; therefore, in some display substrates, full-color display can be achieved by using a blue LED light emitting chip + color conversion structure. Correspondingly, in the transfer process of the LED light emitting chip, only one color of LED light emitting chip needs to be transferred, thereby improving the transfer efficiency and reducing the repair difficulty.

[0054] In related technologies, for the repair technology of the display substrate, 3 or 6 redundant sub-pixels are designed in the pixel unit of the three display sub-pixels, that is, 6 or 9 LED light emitting chips are included in each pixel unit, which results in that the resolution of the display panel using the display substrate is difficult to improve, and the preparation cost is relatively high.

[0055] To solve the above problems, the present embodiment provides the following technical solutions. Before the present embodiment is described, it should be noted that, in the present embodiment, only a light emitting chip is taken as an example of a blue light color LED light emitting chip, i.e., the first color is blue. Each pixel unit includes three display sub-pixels, namely a first sub-pixel, a second sub-pixel, and a third sub-pixel. The second color in the present embodiment is red, and the third color is green.

[0056] FIG. 1 is a cross-sectional view of an exemplary light emitting chip. As shown in FIG. 1, the light emitting chip can be specifically an LED chip, which includes a transparent substrate 21 and a semiconductor layer stack disposed on the transparent substrate 21.

[0057] The transparent substrate 21 can be sapphire, but is not limited thereto. In addition to an insulating substrate, the transparent substrate 21 can be a conductive substrate or a semiconductor substrate that can ensure light transmission properties. A concave-convex structure (not shown in the figure) can be formed on the upper surface of the transparent substrate 21. The concave-convex structure can improve light extraction efficiency and can improve the growth quality of a single crystal.

[0058] The semiconductor layer stack can include a first semiconductor layer 22, an active layer 23, and a second semiconductor layer 24. Among them, the first semiconductor layer can be an n-type nitride semiconductor layer containing In x Al y Ga 1-x-y N (0≤x<1, 0≤y<1, 0≤x+y<1), and the n-type impurity can be silicon. For example, the first semiconductor layer 21 can contain n-type GaN. The second semiconductor layer 24 can be a p-type nitride semiconductor layer containing In x Al y Ga 1-x-y N (0≤x<1, 0≤y<1, 0≤x+y<1), and the p-type impurity can be magnesium. For example, the second semiconductor layer 24 can be a single-layer structure, but as in some example embodiments, it can have a multi-layer structure containing different compositions. The active layer 23 can have a multi-quantum well (MQW) structure, in which quantum well layers and quantum barrier layers are alternately stacked with each other. For example, the quantum well layers and the quantum barrier layers can respectively include different compositions of In x Al y Ga 1-x-y N (0≤x≤1, 0≤y≤1, 0≤x+y≤1). In a certain example, the quantum well layer can include a composition of In x Ga 1-x N (0<x≤1), and the quantum barrier layer can include GaN or AlGaN. The active layer 23 is not limited to the MQW structure, and can have a single quantum well (SQW) structure.

[0059] In some examples, a buffer layer (not shown in the figures) can be provided between the transparent substrate 21 and the first semiconductor layer 22, and the buffer layer can have a composition of In x Al y Ga 1-x-y N (0≤x≤1, 0≤y≤1). For example, the buffer layer can include GaN, AlN, AlGaN, or InGaN. If necessary, the buffer layer can also be formed by combining multiple layers or gradually changing its composition.

[0060] In some examples, the LED chip includes a first electrode and a second electrode 25 can be provided on the mesa-etched region of the first semiconductor layer 22 and the second semiconductor layer 24, respectively, so that the first electrode and the second electrode 25 can be located on the same side of the LED chip. For example, the first electrode can include at least one of Al, Au, Cr, Ni, Ti, and Sn. The second electrode can include a reflective metal. For example, the second electrode 25 can include a material such as Ag, Ni, Al, Cr, Rh, Pd, Ir, Ru, Mg, Zn, Pt, or Au, and can be used as a structure having a single layer or two or more layers.

[0061] In some examples, as shown in FIG. 1, the light emitting chip can also not be provided with a first electrode, and only a second electrode 25 is provided, which is a transparent electrode, for example, the material of the second electrode 25 is selected from a transparent conductive material such as ITO. In this case, an insulating layer 26 is provided on the side of the second electrode 25 away from the second semiconductor layer 24, a first pad 201 is provided on the mesa-etched region of the first semiconductor layer 22 through a via hole penetrating the insulating layer 26, and a second pad 202 is provided on the second electrode 25 through a via hole penetrating the insulating layer 26, and the first pad 201 and the second pad 202 can be located on the same side of the LED chip. Further, a current blocking layer 27 can also be provided between the second electrode 25 and the second semiconductor layer 24.

[0062] It should also be noted that in the embodiments of the present disclosure, when the LED chip is a blue light LED chip, the color conversion layer can be composed of red light color conversion material and green light color conversion material. For example: the material of the color conversion layer is selected from quantum dots or phosphor. When the material of the color conversion layer is selected from quantum dots, the material of the color conversion layer can specifically include red quantum dots and green quantum dots, in which case the blue light emitted by the blue light LED chip can excite the red quantum dots to emit red light and excite the green quantum dots to emit green light. When the material of the color conversion layer is selected from phosphor, the material of the color conversion layer can specifically include red phosphor and green phosphor, in which case the blue light emitted by the blue light LED chip can excite the red phosphor to emit red light and excite the green phosphor to emit green light.

[0063] FIG. 2 is a schematic diagram of a display substrate according to an embodiment of the present disclosure; as shown in FIG. 2, the display substrate according to an embodiment of the present disclosure includes a substrate 10 and a plurality of pixel units A disposed on the substrate 10. Each pixel unit A includes a plurality of sub-pixels, each of which includes a pixel driving circuit, a light emitting chip 20, a first pad 101 connected to the pixel driving circuit, and a second pad. The first electrode of the light emitting chip 20 is configured to be connected to the first pad 101, and the second electrode of the light emitting chip 20 is configured to be connected to the second pad. At least part of the sub-pixels in the pixel unit A that can be lit are display sub-pixels 100, and the remaining sub-pixels are redundant sub-pixels 200. The light emitting side of the light emitting chip 20 of at least part of the display sub-pixels 100 is provided with a color conversion layer 40. The number of display sub-pixels 100 in the pixel unit A is greater than the number of redundant sub-pixels 200.

[0064] It should be noted that whether there is a "bad point" in each pixel unit A, i.e., whether each sub-pixel in each pixel unit A has a sub-pixel that cannot emit light, needs to be detected, for example, by using an optical detection device (AOI) to detect whether the light emitting chip 20 has a bonding abnormality.

[0065] The light emitting chip 20 in the embodiment of the present disclosure includes but is not limited to a Micro-LED light emitting chip 20 or a Mini-LED light emitting chip 20.

[0066] In the embodiment of the present disclosure, taking three display sub-pixels 100 required for each pixel unit A as an example, the display substrate according to the embodiment of the present disclosure is subjected to "bad point" detection during preparation, so the number of redundant sub-pixels 200 in each pixel unit A can be one or two, that is, four or five sub-pixels are formed in each pixel unit A, and only one or two standby sub-pixels are activated when a "bad point" exists in the pixel unit A. Compared with the related art, the display substrate according to the embodiment of the present disclosure can realize a high PPI design, and the cost will be greatly reduced.

[0067] In some examples, each sub-pixel of the pixel unit A in the embodiment of the present disclosure can be arranged in the following manner, it should be understood that the following only gives a few exemplary arrangement manners, but does not constitute a limitation on the protection scope of the embodiment of the present disclosure.

[0068] The first example: Fig. 3 is the corresponding relationship between the display sub-pixel 100 and the color conversion layer 40 in the first example of the pixel arrangement of the embodiment of the present disclosure. As shown in Fig. 3, each pixel unit A includes four sub-pixels, three of which are used as display sub-pixels 100, and one of which is used as a redundant sub-pixel 200. The four sub-pixels in the pixel unit A are arranged in an array. For each pixel unit A, assuming that the preset pixel arrangement is: the sub-pixel for emitting red light is located in the first row and the first column, the sub-pixel for emitting green light is located in the first row and the second column, and the sub-pixel for emitting blue light is located in the second row and the first column. In this case, the sub-pixel located in the second row and the second column in each pixel unit A is a redundant sub-pixel. After light emission detection, if each sub-pixel in the pixel unit A can emit light, then the three sub-pixels located in the first row and the first column, the first row and the second column, and the second row and the first column are used as display sub-pixels 100, and the sub-pixel located in the second row and the second column is used as a redundant sub-pixel 200. If there is a "bad point" in the pixel unit A, then the sub-pixel located in the second row and the second column is used as a display sub-pixel 100, replacing the "bad point", and the "bad point" corresponds to the redundant sub-pixel 200, and the remaining sub-pixels are all used as display sub-pixels 100.

[0069] Continuing to refer to Fig. 3, accordingly, according to the position information of the display sub-pixel 100, the color conversion layer 40 forms a first color conversion pattern 401 and a second color conversion pattern 402 at the corresponding positions, i.e., red quantum dots and green quantum dots. The position of the emitted blue light can be a hollow pattern. The position of the color conversion black is to represent that a light shielding pattern or a reflective layer will be formed at this position subsequently, which can also be a hollow pattern in fact.

[0070] The second example: FIG. 4 is a corresponding relationship between the display sub-pixel 100 and the color conversion layer 40 under the pixel arrangement of the second example of the embodiment of the present disclosure; as shown in FIG. 4, the difference between this example and the first example is that in each pixel unit A of this example, five sub-pixels are included, three of which are used as display sub-pixels 100, and two of which are used as redundant sub-pixels 200. The five sub-pixels in the pixel unit A are arranged in two rows, one row of three sub-pixels and one row of four sub-pixels. For each pixel unit A, assuming that the preset pixel arrangement mode is that the sub-pixel for emitting red light is located at the first position of the first row, the sub-pixel for emitting green light is located at the second position of the first row, and the sub-pixel for emitting blue light is located at the third position of the first row; the two sub-pixels located at the second row are redundant sub-pixels. After the light emitting detection is performed, if each sub-pixel in the pixel unit A can emit light, then the first, second and third sub-pixels of the first row are used as display sub-pixels 100, and the two sub-pixels of the second row are used as redundant sub-pixels 200. If there is a "bad point" in the three sub-pixels of the first row in the pixel unit A, then the sub-pixel of the second row is used as a display sub-pixel 100 to replace the "bad point", and the "bad point" is used as a redundant sub-pixel 200, and the remaining sub-pixels are all used as display sub-pixels 100.

[0071] Continuing to refer to FIG. 4, accordingly, according to the position information of the display sub-pixel 100, the color conversion layer 40 forms the first color conversion pattern 401 and the second color conversion pattern 402 at the corresponding positions, i.e., red quantum dots and green quantum dots. The position of the emitted blue light is a hollow pattern in the color conversion layer 40. The position of the color conversion black is to indicate that a light shielding pattern or a reflective layer is formed at this position subsequently, which is actually also a hollow pattern. The third mode: FIG. 5 is a corresponding relationship between the display sub-pixel 100 and the color conversion layer 40 under the pixel arrangement of the third example of the embodiment of the present disclosure; as shown in FIG. 5, each pixel unit A includes four sub-pixels, three of which are used as display sub-pixels 100, and one of which is used as a redundant sub-pixel 200. The four sub-pixels in the pixel unit A are arranged side by side. For each pixel unit A, assuming that the preset pixel arrangement mode is that the sub-pixel for emitting red light is located at the first position, the sub-pixel for emitting green light is located at the second position, and the sub-pixel for emitting blue light is located at the third position, in which case, for the sub-pixel located at the fourth position in each pixel unit A, it is a redundant sub-pixel. After the light emitting detection is performed, if each sub-pixel in the pixel unit A can emit light, then the first, second and third sub-pixels are used as display sub-pixels 100, and the fourth sub-pixel is used as a redundant sub-pixel 200. If there is a "bad point" in the first three sub-pixels in the pixel unit A, then the fourth sub-pixel is used as a display sub-pixel 100 to replace the "bad point", and the "bad point" is used as a redundant sub-pixel 200, and the remaining sub-pixels are all used as display sub-pixels 100.

[0072] Continuing to refer to FIG. 5, correspondingly, according to the position information of the display sub-pixel 100, the color conversion layer 40 forms the first color conversion pattern 401 and the second color conversion pattern 402 at the corresponding positions, i.e., the red quantum dots and the green quantum dots. The position where the blue light is emitted is a position where the color conversion layer 40 can be a hollow pattern. The position where the black color is converted is a position where a light shielding pattern or a reflective layer is formed subsequently, which can actually also be a hollow pattern.

[0073] The fourth mode: FIG. 6 is a fourth example of the pixel arrangement of the embodiment of the present disclosure, and the corresponding relationship between the display sub-pixel 100 and the color conversion layer 40; as shown in FIG. 6, each pixel unit A includes five sub-pixels, three of which are used as display sub-pixels 100, and two of which are used as redundant sub-pixels 200. One of the five sub-pixels is surrounded by the other four sub-pixels, and the four sub-pixels are arranged in an array. Assuming that the preset pixel arrangement mode is that the sub-pixel for emitting red light is located in the first row and the first column, the sub-pixel for emitting green light is located in the first row and the second column, and the sub-pixel for emitting blue light is located in the second row and the first column, in this case, the sub-pixel located in the second row and the second column and the sub-pixel located in the middle of the pixel unit A are redundant sub-pixels. After light emission detection, if each sub-pixel in the pixel unit A can emit light, then the three sub-pixels located in the first row and the first column, the first row and the second column, and the second row and the first column of the four sub-pixels arranged in an array are used as display sub-pixels 100, and the sub-pixel located in the second row and the second column and the sub-pixel located in the middle of the pixel unit A are used as redundant sub-pixels 200. If there is a "bad point" in the pixel unit A, then the sub-pixel located in the second row and the second column and / or the sub-pixel located in the middle of the pixel unit A are used as display sub-pixels 100, replacing the "bad point", and the "bad point" corresponds to the redundant sub-pixel 200, and the remaining sub-pixels are all display sub-pixels 100.

[0074] Continuing to refer to FIG. 6, correspondingly, according to the position information of the display sub-pixel 100, the color conversion layer 40 forms the first color conversion pattern 401 and the second color conversion pattern 402 at the corresponding positions, i.e., the red quantum dots and the green quantum dots. The position where the blue light is emitted is a position where the color conversion layer 40 can be a hollow pattern. The position where the black color is converted is a position where a light shielding pattern or a reflective layer is formed subsequently, which can actually also be a hollow pattern.

[0075] It should be noted that the arrangement of the sub-pixels in each pixel unit A in the embodiments of the present disclosure is designed based on a preset arrangement of the sub-pixels in the pixel unit A, and the size and spacing of the sub-pixels corresponding to different color lights. For example, for the "pin-shaped" pixel arrangement in the related art, three sub-pixels are actually displayed, and one or two sub-pixels can be added to each pixel unit A in the embodiments of the present disclosure in combination with the size and spacing of the original three sub-pixels, to form the pixel unit A in the embodiments of the present disclosure.

[0076] In some examples, referring to FIG. 1, the light-emitting chip 20 includes a first electrode, a first semiconductor layer, an active layer, a second semiconductor layer, and a second electrode layer stacked in sequence away from the substrate 10. A bonding structure is formed on the side of the first pad 101 away from the substrate 10, and the first electrode is provided with a first pad 201 on the side close to the bonding structure, and the first electrode is bonded to the bonding structure through the first pad 201 to realize the electrical connection between the first electrode of the light-emitting chip 20 and the first pad 101. The second electrode of the light-emitting chip 20 and the second pad can be connected through a connecting electrode, or the second electrode can be directly extended to directly connect with the second pad.

[0077] Further, referring to FIG. 1, the bonding structure includes at least one bonding part 30, and the bonding part 30 includes an intermetallic compound (IMC) barrier layer 301 and a bonding layer 302 arranged in sequence away from the substrate 10. The intermetallic compound barrier layer 301 is made of conductive material and is used to prevent the metal materials on both sides from reacting with each other to form an intermetallic compound.

[0078] In some examples, the material of the intermetallic compound barrier layer 301 includes at least one of Mo and Ti. For example, the intermetallic compound barrier layer 301 can be a Mo metal layer, a Ti metal layer, or a stacked structure of the two.

[0079] In some embodiments, the thickness of the intermetallic compound barrier layer 301 is between 0.1 and 0.5 microns, so as to prevent the overall thickness of the bonding structure from being too large while ensuring the barrier effect. For example, the thickness of the intermetallic compound barrier layer 301 is 0.1 microns, or 0.25 microns, or 0.35 microns, or 0.5 microns.

[0080] In some examples, referring to FIG. 1, the display substrate not only includes the above structure, but also can include a planarization layer 60 arranged on the side of the light-emitting chip 20 away from the substrate substrate 10. Specifically, the planarization layer 60 includes a first part and a second part, the first part is arranged between adjacent bonding structures and adjacent light-emitting units, and the second part is located on the side of the light-emitting unit away from the substrate substrate 10. Among them, the first part and the second part are an integral structure. Through the arrangement of the planarization layer 60, it can prevent the display substrate from having a large step difference, so as to facilitate the manufacture of subsequent structures. In some examples, the surface of the planarization layer 60 away from the substrate substrate 10 can be a flat or substantially flat surface. Among them, the planarization layer 60 can be made of an organic material, thereby facilitating the planarization layer 60 to form a flat surface.

[0081] In some examples, referring to FIG. 1, the display substrate not only includes the above structure, but also can include a light shielding pattern or a reflective layer arranged on the light-emitting side of the light-emitting chip 20 of the sub-pixel capable of emitting light in the redundant sub-pixel 200. In this case, the light emitted by the sub-pixel capable of emitting light in the redundant sub-pixel 200 can be avoided from affecting the display.

[0082] Further, the light shielding pattern includes but is not limited to a black matrix, and in the embodiments of the present disclosure, only the black matrix is taken as an example of the light shielding pattern. When the light shielding pattern adopts the black matrix, a black matrix layer 50 can be arranged on the side of the planarization layer 60 away from the substrate substrate 10, the black matrix layer 50 has an opening penetrating in the thickness direction of the black matrix layer 50 at positions corresponding to each light-emitting chip 20 in the first sub-pixel R, the second sub-pixel G and the third sub-pixel B, and the remaining positions of the black matrix layer 50 are black matrix patterns 501. In this way, not only the black matrix patterns 501 are formed on the light-emitting side of the light-emitting chip 20 of the sub-pixel capable of emitting light in the redundant sub-pixel 200, but also the black matrix patterns 501 are formed between each light-emitting chip 20 in the first sub-pixel R, the second sub-pixel G and the third sub-pixel B. Through the arrangement of the black matrix patterns 501, the light crosstalk between adjacent sub-pixels can also be prevented. Further, the thickness of the black matrix layer 50 formed in the embodiments of the present disclosure is about 2-15 μm, and the thickness of the red quantum dots and the green quantum dots is about 1-10 μm. Through the reasonable thickness of the black matrix layer 50 and the thickness of the red quantum dots and the green quantum dots, the light crosstalk between the sub-pixels can be better prevented.

[0083] Further, when the reflective layer is arranged on the light-emitting side of the light-emitting chip 20 of the sub-pixel capable of emitting light in the redundant sub-pixel 200, the material of the reflective layer includes but is not limited to Ag. In this case, the black matrix layer 50 described above can also be formed on the light-emitting side of the light-emitting chip 20 to prevent the light crosstalk between adjacent sub-pixels.

[0084] In some examples, in order to improve the color gamut, a color gamut improving layer can also be formed on the side of the red quantum dots and the green quantum dots away from the substrate 10, which can be a distributed Bragg reflection mirror (DBR), an absorption color resist, or a semi-transparent half-reflection film 80, which will be described one by one below.

[0085] In one example, FIG. 7 is a schematic diagram of an exemplary display substrate according to an embodiment of the present disclosure; as shown in FIG. 7, when the color gamut improving layer is a distributed Bragg reflection mirror (DBR), the reflectivity of the distributed Bragg reflection mirror to red light and green light is less than the reflectivity to blue light, and the transmittance of the distributed Bragg reflection mirror to red light and green light is greater than the transmittance to blue light. That is, the distributed Bragg reflection mirror has high reflectivity to blue light and high transmittance to red light and green light. In this example, the distributed Bragg reflection mirror highly reflects blue light, so that the reflected blue light can further excite the red quantum dots to convert into red light and the green quantum dots to convert into green light, thereby improving the color conversion efficiency of the red quantum dots and the green quantum dots and alleviating the problem of blue light bias in the backlight light emission.

[0086] Further, the distributed Bragg reflection mirror is composed of alternately arranged first film layers and second film layers, the refractive indices of the first film layers and the second film layers are different, and for example, the refractive index of the first film layer is greater than the refractive index of the second film layer. The refractive indices of the first film layers and the second film layers determine the reflectivity of the distributed Bragg reflection mirror. Specifically, the reflectivity of the distributed Bragg reflection mirror is calculated according to the following formula:

[0087] wherein N represents the number of pairs of media layers (each pair of media layers is composed of one first film layer and one second film layer arranged adjacently), n H is the refractive index of the first film layer, n L is the refractive index of the second film layer, n o is the refractive index of the incident medium, n i is the refractive index of the exit medium; the bandwidth Δλ of the photonic band gap is given by the following formula:

[0088] wherein λ0 is the center wavelength of the wavelength band.

[0089] Further, one type of distributed Bragg reflection mirror is composed of alternately arranged titanium dioxide TiO2 and zinc oxide ZnO, and another type of distributed Bragg reflection mirror is composed of alternately arranged zinc oxide ZnO and silicon dioxide SiO2.

[0090] In another example, FIG. 8 is a schematic diagram of another exemplary display substrate according to an embodiment of the present disclosure; as shown in FIG. 8, the color gamut enhancement layer adopts an absorption type color film. Specifically, a red color filter 701 is arranged on the side of the red quantum dots corresponding to the first sub-pixel R away from the substrate 10, a green color filter 702 is arranged on the side of the green quantum dots corresponding to the second sub-pixel G away from the substrate 10, and of course a blue color filter 703 can also be formed at the position corresponding to the third sub-pixel B. Among them, the red color filter 701 emits red light and absorbs green light and blue light, the green color filter 702 emits red light and absorbs red light and blue light, the blue color filter 703 emits blue light and absorbs red light and green light, and the color gamut can be improved in this way.

[0091] In another example, FIG. 9 is a schematic diagram of another exemplary display substrate according to an embodiment of the present disclosure; as shown in FIG. 9, the color gamut enhancement layer adopts a semi-transmissive and semi-reflective film 80 layer, and the semi-transmissive and semi-reflective film layer is arranged on the side of the red quantum dots corresponding to the first sub-pixel R and the green quantum dots corresponding to the second sub-pixel G away from the substrate 10. The semi-reflective and semi-transmissive film layer is configured to transmit a part of the light emitted by the light emitting chip 20 and reflect the other part.

[0092] Since the conversion efficiency of the color conversion layer 40 is not high, the outcoupling efficiency of blue light will be greater than that of red / green light. In this example, by arranging the semi-reflective and semi-transmissive film layer, a part of the blue light emitted by the light emitting chip 20 is transmitted and the other part is reflected, and the reflected blue light can be further converted by the red quantum dots into red light and by the green quantum dots into green light, thereby improving the color conversion efficiency of the red quantum dots and the green quantum dots and alleviating the problem of blue bias of the backlight outcoupling.

[0093] In some examples, the substrate 10 in the embodiments of the present disclosure can adopt a hard substrate of glass-based material or the like; or a flexible substrate of polyimide (PI) material or the like.

[0094] FIG. 10 is a partial flowchart of a preparation method of a display substrate according to an embodiment of the present disclosure; as shown in FIG. 10, the present disclosure provides a preparation method of a display substrate, which can be used to prepare the display substrate described above. The preparation method in the embodiments of the present disclosure includes the following steps:

[0095] S1, providing a substrate 10.

[0096] The substrate 10 in the embodiments of the present disclosure includes but is not limited to a glass substrate, and in the embodiments of the present disclosure, only the glass substrate is taken as an example.

[0097] S2, forming a plurality of pixel units A on the substrate 10, the pixel unit A includes a plurality of sub-pixels, the sub-pixel includes a pixel driving circuit, a light emitting chip 20, a first pad 101 and a second pad, the first pad 101 is connected with the pixel driving circuit; the first electrode of the light emitting chip 20 is configured to be connected with the first pad 101, and the second electrode of the light emitting chip 20 is configured to be connected with the second pad.

[0098] In some examples, the pixel driving circuit formed in step S2 can be composed of thin film transistors, storage capacitors and the like electrical elements, so that the step of forming the pixel driving circuit in step S2 can include the step of forming the gate, the active layer, the source and the drain of the thin film transistor, and the first plate and the second plate of the storage capacitor and the like film layers on the substrate 10 through a patterning process.

[0099] Further, in step S2, after the first pad 101 and the second pad are formed, the first electrode and the second electrode of the light emitting chip 20 can be electrically connected with the first pad 101 and the second pad respectively by bonding through the use of the massive transfer technology. For example, the light emitting chip 20 includes a first electrode, a first semiconductor layer, an active layer, a second semiconductor layer and a second electrode layer which are sequentially stacked in the direction away from the substrate 10. A bonding structure is formed on the side of the first pad 101 away from the substrate 10, a first pad 201 is formed on the side of the first electrode close to the bonding structure, and the first electrode is bonded with the bonding structure through the first pad 201 to realize the electrical connection between the first electrode of the light emitting chip 20 and the first pad 101. The second electrode of the light emitting chip 20 can be connected with the second pad through a connecting electrode, or the second electrode can be directly extended to be directly connected with the second pad.

[0100] It should be noted that the bonding in the embodiment of the present disclosure can be specifically eutectic bonding.

[0101] Further, the bonding structure includes at least one bonding part 30, the bonding part 30 includes an intermetallic compound (IMC) barrier layer 301 and a bonding layer 302 which are sequentially arranged in the direction away from the substrate 10, the intermetallic compound barrier layer 301 is made of conductive material and is used to prevent the metal materials on both sides from reacting with each other to form intermetallic compounds.

[0102] In some examples, step S2 can further form a planarization layer 60 on the side of the light emitting chip 20 away from the substrate substrate 10 after forming the light emitting chip 20. Specifically, the planarization layer 60 includes a first portion and a second portion, the first portion is arranged between adjacent bonding structures and adjacent light emitting units, and the second portion is located on the side of the light emitting unit away from the substrate substrate 10. The first portion and the second portion are an integral structure. By arranging the planarization layer 60, a large step difference can be prevented on the display substrate, so as to facilitate the subsequent manufacturing of the structure. In some embodiments, the surface of the planarization layer 60 away from the substrate substrate 10 can be a flat or substantially flat surface. The planarization layer 60 can be made of an organic material, so as to facilitate the planarization layer 60 to form a flat surface.

[0103] S3, detecting whether the sub-pixels of each pixel unit A can be lit, taking at least part of the sub-pixels of the pixel unit A that can be lit as display sub-pixels 100, and taking the remaining sub-pixels as redundant sub-pixels 200.

[0104] In some examples, in step S3, a gate scanning signal can be provided to the pixel driving circuit row by row, and a driving voltage can be provided to the corresponding light emitting chip 20 through the pixel driving circuit. By observing the light emitting state of the light emitting chip 20, it can be determined whether there is a "dead pixel" in each pixel unit A, i.e., there is a light emitting chip 20 that cannot be lit. Taking an example of a pixel unit A provided with four sub-pixels, and three sub-pixels in each pixel unit A being used for display, when it is detected that all four sub-pixels in the pixel unit A can be lit, three of them are selected as display sub-pixels 100, and the remaining one is selected as a redundant sub-pixel 200. When it is detected that three of the four sub-pixels in the pixel unit A can be lit, and one cannot be lit, the sub-pixels that can be lit are selected as display sub-pixels 100, and the sub-pixel that cannot be lit is a redundant sub-pixel 200.

[0105] Further, when it is detected that each sub-pixel in the pixel unit A can be lit, the corresponding sub-pixels are preferably selected as display sub-pixels 100 according to a preset pixel arrangement mode. For example, the preset pixel arrangement mode is "pin shape", so the display sub-pixels 100 are determined according to the corresponding position information of the sub-pixels required by the "pin shape". In this way, display uniformity can be provided. It should be noted that for the redundant sub-pixels 200 that can be lit, in order to avoid affecting the display, it is necessary to ensure that the redundant sub-pixels 200 do not emit light, for example, a light shielding structure or a reflecting structure is formed on the light emitting side of the redundant sub-pixel 200, or the pixel driving circuit in the redundant sub-pixel 200 is disconnected from the light emitting chip 20, etc.

[0106] S4, forming a color conversion layer 40 according to the position information of the display sub-pixel 100.

[0107] In some examples, the color conversion layer 40 material formed in step S4 includes quantum dots or phosphor powder. In the present embodiment, only the selection of quantum dots as the material of the color conversion layer 40 is taken as an example. Step S4 can specifically include forming a first color conversion pattern 401, i.e., red quantum dots, on the light emitting side of the light emitting chip 20 of the first sub-pixel R, and forming a second color conversion pattern 402, i.e., green quantum dots, on the light emitting side of the light emitting chip 20 of the second sub-pixel G. Since the light emitted by the light emitting chip 20 is blue light, the color conversion layer 40 can be hollow on the light emitting side of the light emitting chip 20 of the third sub-pixel B, and of course, a transparent medium layer can be filled in the hollow pattern, which is not limited in the present embodiment. In this way, the blue light emitted by the light emitting chip 20 in the first sub-pixel R excites the red quantum dots on the light emitting side thereof, and emits red light, the blue light emitted by the light emitting chip 20 in the second sub-pixel G excites the green quantum dots on the light emitting side thereof, and emits green light, and the blue light emitted by the light emitting chip 20 in the third sub-pixel B is directly emitted, thereby realizing full-color display. For the quantum dot material in step S4, the light emitting side of the light emitting chip 20 can be directly formed, or the quantum dot material can be attached to the light emitting side of the light emitting chip 20 in a lamination manner.

[0108] In the present embodiment, since the light emitting of each sub-pixel is detected before the color conversion layer 40 is formed, it is determined that there are “bad points” in each pixel unit A, and then the display sub-pixel 100 in each pixel unit A is determined according to the “bad point” condition to prepare the color conversion layer 40, so that in step S2, there is no need to form too many sub-pixels in each pixel unit A. For example, when the number of display sub-pixels 100 required by the pixel unit A is three, four or five sub-pixels are formed in each pixel unit A in step S2, i.e., only one or two standby sub-pixels are needed to be activated when there is a “bad point” in the pixel unit A. Compared with the related art, the display substrate of the present embodiment can realize high PPI design, and the cost will be greatly reduced.

[0109] In some examples, the preparation method of the display substrate in the present embodiment not only includes the above steps, but also includes determining the position information of the sub-pixel capable of emitting light in the redundant sub-pixel 200; and forming a light shielding pattern or a reflective layer on the light emitting side of the light emitting chip 20 of the sub-pixel capable of emitting light in the redundant sub-pixel 200. In this case, the emitted light of the sub-pixel capable of emitting light in the redundant sub-pixel 200 can be avoided from affecting the display.

[0110] Further, the light shielding pattern includes but is not limited to a black matrix, and in the embodiments of the present disclosure, only the black matrix is taken as an example of the light shielding pattern. When the light shielding pattern is the black matrix, before the color conversion layer 40 is formed, the black matrix layer 50 can be formed on the side of the planarization layer 60 away from the substrate 10, and the black matrix layer 50 is patterned to form an opening corresponding to each light emitting chip 20 in the first sub-pixel R, the second sub-pixel G and the third sub-pixel B. The remaining positions form a black matrix pattern 501. In this way, not only the light emitting chip 20 of the sub-pixel capable of emitting light in the redundant sub-pixel 200 is formed on the light emitting side of the black matrix pattern 501, but also the black matrix pattern 501 is formed between each light emitting chip 20 in the first sub-pixel R, the second sub-pixel G and the third sub-pixel B. By setting the black matrix pattern 501, the light crosstalk between adjacent sub-pixels can also be prevented. Further, the thickness of the black matrix layer 50 formed in the embodiments of the present disclosure is about 2-15 μm, and the thickness of the red quantum dots and the green quantum dots is about 1-10 μm. By reasonably setting the thickness of the black matrix layer 50 and the thickness of the red quantum dots and the green quantum dots, the light crosstalk between the sub-pixels can be better prevented.

[0111] Further, when the reflective layer is formed on the light emitting side of the light emitting chip 20 of the sub-pixel capable of emitting light in the redundant sub-pixel 200, the material of the reflective layer includes but is not limited to Ag. In this case, the black matrix layer 50 described above can also be formed on the light emitting side of the light emitting chip 20 to prevent the light crosstalk between adjacent sub-pixels.

[0112] In some examples, the preparation method of the display substrate in the embodiments of the present disclosure not only includes the above steps, but also a color gamut enhancement layer can be formed on the side of the red quantum dots and the green quantum dots away from the substrate 10 in order to improve the color gamut. The color gamut enhancement layer can be a distributed Bragg reflector DBR (DBR; distributed Bragg reflection), an absorption type color resistance, or a semi-transparent and semi-reflective film 80 layer, which will be described one by one.

[0113] The first case: a distributed Bragg reflector (DBR) is formed on the side of the red quantum dots corresponding to the first sub-pixel R and the green quantum dots corresponding to the second sub-pixel G away from the substrate 10. The reflectivity of the distributed Bragg reflector to red light and green light is less than the reflectivity to blue light; and the transmittance of the distributed Bragg reflector to red light and green light is greater than the transmittance to blue light. That is, the distributed Bragg reflector has high reflectivity to blue light and high transmittance to red light and green light. In this example, the blue light is highly reflected by the distributed Bragg reflector, so that the reflected blue light can further excite the red quantum dots to convert into red light and the green quantum dots to convert into green light, thereby improving the color conversion efficiency of the red quantum dots and the green quantum dots and alleviating the problem of blue light bias in the backlight light emission.

[0114] The distributed Bragg reflector is composed of first film layers and second film layers arranged alternately, and the refractive indexes of the first film layers and the second film layers are different. For example, the refractive index of the first film layer is greater than that of the second film layer. The refractive indexes of the first film layers and the second film layers determine the reflectivity of the distributed Bragg reflector. Specifically, the reflectivity of the distributed Bragg reflector is calculated according to the following formula:

[0115] wherein N represents the number of pairs of media layers (each pair of media layers is composed of one first film layer and one second film layer arranged adjacently), n H is the refractive index of the first film layer, n L is the refractive index of the second film layer, n o is the refractive index of the incident medium, n i is the refractive index of the exit medium; the bandwidth Δλ of the photonic band gap is given by the following formula:

[0116] wherein λ0 is the center wavelength of the wavelength band.

[0117] Further, one type of distributed Bragg reflector is composed of titanium dioxide TiO2 and zinc oxide ZnO arranged alternately, and another type of distributed Bragg reflector is composed of zinc oxide ZnO and silicon dioxide SiO2 arranged alternately.

[0118] The second case: a red color resistance 701 is formed on the side of the red quantum dots corresponding to the first sub-pixel R away from the substrate 10, a green color resistance 702 is formed on the side of the green quantum dots corresponding to the second sub-pixel G away from the substrate 10, and a blue color resistance 703 can also be formed at the position corresponding to the third sub-pixel B. The red color resistance 701 emits red light and absorbs green light and blue light, the green color resistance 702 emits green light and absorbs red light and blue light, and the blue color resistance 703 emits blue light and absorbs red light and green light. In this way, the color gamut can be improved.

[0119] The third case: a semi-transmissive and semi-reflective film 80 layer is formed on the side of the red quantum dots corresponding to the first sub-pixel R and the green quantum dots corresponding to the second sub-pixel G away from the substrate 10, and the semi-reflective and semi-transmissive film layer is configured to transmit a part of the light emitted by the light-emitting chip 20 and reflect the other part.

[0120] Since the conversion efficiency of the color conversion layer 40 is not high, the outcoupling efficiency of blue light is greater than that of red / green light. In this example, by setting the semi-reflective and semi-transmissive film layer, a part of the blue light emitted by the light-emitting chip 20 is transmitted and the other part is reflected, and the reflected blue light can further excite the red quantum dots to convert into red light and the green quantum dots to convert into green light, thereby improving the color conversion efficiency of the red quantum dots and the green quantum dots and alleviating the problem of blue bias of the backlight outcoupling.

[0121] The display device can include any device or product having a display function. For example, the display device can be a smart phone, a mobile phone, an electronic book reader, a desktop PC (personal computer), a laptop PC, a netbook PC, a personal digital assistant (PDA), a portable multimedia player (PMP), a digital audio player, a mobile medical device, a camera, a wearable device (e.g., a head-mounted device, electronic clothing, an electronic bracelet, an electronic necklace, electronic accessories, electronic tattoos, or a smart watch), a television, etc.

[0122] It can be understood that the above embodiments are only exemplary embodiments adopted for illustrating the principles of the present application, and the present application is not limited thereto. Various modifications and improvements can be made by those of ordinary skill in the art without departing from the spirit and essence of the present application, and these modifications and improvements are also considered to be within the protection scope of the present application.

Claims

1. A display substrate comprising: a substrate substrate; a plurality of pixel units disposed on the substrate substrate, each of the pixel units comprising a plurality of sub-pixels, each of the sub-pixels comprising a pixel driving circuit, a light emitting chip, a first pad and a second pad, the first pad being connected with the pixel driving circuit, a first pole of the light emitting chip being configured to be connected with the first pad, and a second pole of the light emitting chip being configured to be connected with the second pad; wherein at least part of the sub-pixels in each of the pixel units are capable of being lighted up as display sub-pixels, and the remaining sub-pixels are capable of being lighted up as redundant sub-pixels, a light emitting side of the light emitting chip of at least part of the display sub-pixels is provided with a color conversion layer, and a number of the display sub-pixels is greater than a number of the redundant sub-pixels. 2.The display substrate of claim 1, wherein, a light shielding pattern or a reflective layer is provided on the light emitting side of the light emitting chip of the sub-pixel capable of emitting light in the redundant sub-pixels. 3.The display substrate of claim 1, wherein, the light emitting chip is configured to emit light of a first color, the display sub-pixels comprise a first sub-pixel, a second sub-pixel and a third sub-pixel, and the color conversion layer comprises a first color conversion pattern provided on the light emitting side of the light emitting chip of the first sub-pixel and a second color conversion pattern provided on the light emitting side of the light emitting chip of the second sub-pixel; wherein the first color conversion pattern is configured to emit light of a second color under excitation of the light of the first color, and the second color conversion pattern is configured to emit light of a third color under excitation of the light of the first color. 4.The display substrate of claim 3, wherein, a distributed Bragg reflector is provided on the light emitting side of the first color conversion pattern and the second color conversion pattern, the distributed Bragg reflector has a reflectivity to the light of the second color and a reflectivity to the light of the third color, both of which are less than a reflectivity to the light of the first color, and the distributed Bragg reflector has a transmissivity to the light of the second color and a transmissivity to the light of the third color, both of which are greater than a transmissivity to the light of the first color. 5.The display substrate of claim 3, wherein, a color resistance of the second color is provided on the light emitting side of the first color conversion pattern, and a color resistance of the third color is provided on the light emitting side of the second color conversion pattern. 6.The display substrate of claim 3, wherein, a semi-transmissive and semi-reflective film layer is provided on the light emitting side of the first color conversion pattern and the second color conversion pattern, and is configured to transmit part of the light emitted by the light emitting chip and reflect the other part. 7.The display substrate of claim 1, wherein, a material of the color conversion layer comprises quantum dots or fluorescent powder.

8. The display substrate according to any one of claims 1-7, wherein each of the sub-pixels in the pixel units is arranged side by side; alternatively, a number of the sub-pixels in each of the pixel units is four, and the four sub-pixels are arranged in an array; alternatively, a number of the sub-pixels in each of the pixel units is five, one of the five sub-pixels is surrounded by the remaining four sub-pixels, and the four sub-pixels are arranged in an array. 9.The display substrate according to any one of claims 1-7, wherein, the light emitting chip is a Micro-LED light emitting chip or a Mini-LED light emitting chip.

10. A display device comprising the display substrate according to any one of claims 1-9.

11. A method for manufacturing a display substrate, comprising: Providing a substrate; forming a plurality of pixel units on the substrate, each of the pixel units comprising a plurality of sub-pixels, each of the sub-pixels comprising a pixel driving circuit, a light emitting chip, a first pad and a second pad, the first pad being connected to the pixel driving circuit, a first electrode of the light emitting chip being configured to be connected to the first pad, and a second electrode of the light emitting chip being configured to be connected to the second pad; detecting whether each of the sub-pixels of the pixel units can be lit up, and taking the sub-pixels of the pixel units that can be lit up at least partially as display sub-pixels, and taking the remaining sub-pixels as redundant sub-pixels; forming a color conversion layer according to position information of the display sub-pixels. Further comprising: 12.The method of manufacturing the display substrate according to claim 11, wherein determining position information of the sub-pixels of the redundant sub-pixels that can emit light; forming a light shielding pattern or a reflective layer on a light emitting side of the light emitting chip of the sub-pixels of the redundant sub-pixels that can emit light. The light emitting chip is configured to emit light of a first color, the display sub-pixels comprise a first sub-pixel, a second sub-pixel and a third sub-pixel, and the forming of the color conversion layer comprises forming a first color conversion pattern on a light emitting side of the light emitting chip of the first sub-pixel, and forming a second color conversion pattern on a light emitting side of the light emitting chip of the second sub-pixel; wherein 13. The method of manufacturing the display substrate according to claim 11, wherein The first color conversion pattern is configured to emit light of a second color under excitation of the light of the first color, and the second color conversion pattern is configured to emit light of a third color under excitation of the light of the first color. Further comprising forming a distributed Bragg reflector on the light emitting side of the first color conversion pattern and the second color conversion pattern; the distributed Bragg reflector has a reflectivity to the light of the second color and a reflectivity to the light of the third color, both of which are less than a reflectivity to the light of the first color; and the distributed Bragg reflector has a transmissivity to the light of the second color and a transmissivity to the light of the third color, both of which are greater than a transmissivity to the light of the first color.

14. The method of manufacturing the display substrate according to claim 13, wherein Further comprising forming a color resistance of the second color on the light emitting side of the first color conversion pattern, and forming a color resistance of the third color on the light emitting side of the second color conversion pattern.

15. The method of manufacturing the display substrate according to claim 13, wherein, Further comprising forming a semi-transmissive and semi-reflective film layer on the light emitting side of the first color conversion pattern and the second color conversion pattern, which is configured to transmit a part of the light emitted by the light emitting chip and reflect another part of the light.

16. The method of manufacturing the display substrate according to claim 13, wherein The step of forming the color conversion layer according to the position information of the display sub-pixels comprises:

17. The method of producing a display substrate according to any one of claims 11 to 16, wherein forming the color conversion layer directly on the light emitting side of the light emitting chip according to the position information of the display sub-pixels, or adhering the color conversion layer to the light emitting side of the light emitting chip in a manner of adhesion. The number of the redundant sub-pixels in the pixel unit is less than the number of the display sub-pixels.

18. The method of producing a display substrate according to any one of claims 11 to 16, wherein The number of the display sub-pixels in the pixel unit is 3, and the number of the redundant sub-pixels is 1; or the number of the display sub-pixels in the pixel unit is 3, and the number of the redundant sub-pixels is 2.

19. The method of manufacturing the display substrate according to claim 18, wherein, The material of the color conversion layer comprises quantum dots or fluorescent powder.

20. The method of producing a display substrate according to any one of claims 11 to 16, wherein ​

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