Display substrate, preparation method thereof and display device

Abstract

The invention discloses a display substrate, a preparation method thereof and a display device. The display substrate comprises a light-emitting substrate and a liquid crystal panel which are stacked, and the light-emitting substrate is arranged as a backlight source of the liquid crystal panel; in the direction perpendicular to the display substrate, the display substrate further comprises a plurality of groups of first polaroids and second polaroids which are arranged in pairs, and the polarization direction of the first polaroids and the polarization direction of the second polaroids which are arranged in pairs are parallel. The light-emitting substrate comprises a driving back plate and a plurality of backlight units arranged on the driving back plate, the first polarizing films are located on the backlight units, the second polarizing films are located on the sides, away from the driving back plate, of the first polarizing films, and in the plane parallel to the display substrate, the polarization directions of the first polarizing films in the adjacent backlight units intersect.

Description

Technical Field

[0001] The embodiments of the present disclosure relate to the field of display technology, and in particular, to a display substrate and a method for preparing the same, and a display device. Background Art

[0002] Light Emitting Diode (LED) technology has been developed for nearly three decades, from the initial solid-state lighting power supply to the backlight source in the display field to the LED display screen, providing a solid foundation for its wider application. With the development of chip manufacturing and packaging technology, sub-millimeter light emitting diode (Mini Light Emitting Diode, Mini LED) display and micro light emitting diode (Micro Light Emitting Diode, Micro LED) display have gradually become a hot spot in display technology. Micro LED display is mainly used in AR / VR and other fields, while Mini LED display is mainly used in TV and outdoor display.

[0003] The inventors of the present application have found through research that a display substrate using a backlight source design has obvious display halos. Summary of the invention

[0004] The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

[0005] The embodiments of the present disclosure provide a display substrate and a method for manufacturing the same, and a display device, so as to solve the problem that a display substrate with a backlight source design displays obvious halo.

[0006] In a first aspect, an embodiment of the present disclosure provides a display substrate, comprising a stacked light-emitting substrate and a liquid crystal panel, wherein the light-emitting substrate is configured as a backlight source of the liquid crystal panel; in a direction perpendicular to the display substrate, the display substrate further comprises a plurality of groups of first polarizers and second polarizers arranged in pairs, wherein the polarization direction of the first polarizers arranged in pairs is parallel to the polarization direction of the second polarizers; the light-emitting substrate comprises a driving backplane and a plurality of backlight units arranged on the driving backplane, wherein the first polarizer is located in the backlight unit, and the second polarizer is located on a side of the first polarizer away from the driving backplane, and in a plane parallel to the display substrate, the polarization directions of the first polarizers in adjacent backlight units intersect.

[0007] In an exemplary embodiment, the backlight unit includes a substrate, a light-emitting functional layer arranged on the substrate, and a first electrode and a second electrode arranged on the light-emitting functional layer; the first electrode and the second electrode face the driving backplane, the first electrode and the second electrode are electrically connected to the driving backplane respectively, and the light-emitting functional layer is configured to emit light under the action of the voltage of the first electrode and the second electrode.

[0008] In an exemplary embodiment, the light-emitting functional layer includes a first active layer, a quantum well, a second active layer and a current spreading layer arranged in sequence on the substrate; the first electrode is electrically connected to the current spreading layer, and the second electrode is electrically connected to the first active layer.

[0009] In an exemplary embodiment, the first polarizer is located on a side of the current spreading layer away from the substrate; and the second polarizer is located on a side of the substrate away from the light-emitting functional layer.

[0010] In an exemplary embodiment, the display substrate further includes a first flat layer and a second flat layer; the first flat layer is located on a side of the first polarizer away from the substrate, and the orthographic projection of the first flat layer on the substrate covers the orthographic projection of the first polarizer on the substrate; the second flat layer is located on a side of the second polarizer away from the substrate, and the orthographic projection of the second flat layer on the substrate covers the orthographic projection of the second polarizer on the substrate.

[0011] In an exemplary embodiment, the first polarizer is located on a side of the current spreading layer away from the substrate; and the second polarizer is located on a side of the liquid crystal panel away from the light-emitting substrate.

[0012] In an exemplary embodiment, the display substrate further includes a first flat layer and a second flat layer; the first flat layer is located on a side of the first polarizer away from the substrate, and the orthographic projection of the first flat layer on the substrate covers the orthographic projection of the first polarizer on the substrate; the second flat layer is located on a side of the second polarizer away from the liquid crystal panel, and the orthographic projection of the second flat layer on the liquid crystal panel covers the orthographic projection of the second polarizer on the liquid crystal panel.

[0013] In an exemplary embodiment, the first polarizer is located on a side of the substrate away from the light-emitting functional layer; and the second polarizer is located on a side of the liquid crystal panel away from the light-emitting substrate.

[0014] In an exemplary embodiment, the display substrate further includes a first flat layer and a second flat layer; the first flat layer is located on a side of the first polarizer away from the substrate, and the orthographic projection of the first flat layer on the substrate covers the orthographic projection of the first polarizer on the substrate; the second flat layer is located on a side of the second polarizer away from the liquid crystal panel, and the orthographic projection of the second flat layer on the liquid crystal panel covers the orthographic projection of the second polarizer on the liquid crystal panel.

[0015] In an exemplary embodiment, the backlight unit includes a light-emitting functional layer and a first electrode and a second electrode arranged on the light-emitting functional layer; the first electrode and the second electrode face the driving backplane, the first electrode and the second electrode are electrically connected to the driving backplane respectively, and the light-emitting functional layer is configured to emit light under the action of the voltage of the first electrode and the second electrode; the light-emitting functional layer includes a first active layer, a quantum well, a second active layer and a current expansion layer arranged in sequence, and the current expansion layer faces the driving backplane; the first electrode and the current expansion layer are electrically connected, and the second electrode and the first active layer are electrically connected; the first polarizer is located on the side of the first active layer away from the driving backplane; the second polarizer is located on the side of the liquid crystal panel away from the light-emitting substrate.

[0016] In an exemplary embodiment, the first polarizer includes a plurality of mutually parallel first wire grids, and the second polarizer includes a plurality of mutually parallel second wire grids, and the first wire grids of the first polarizer and the second wire grids of the second polarizer arranged in pairs are parallel to each other.

[0017] In an exemplary embodiment, the plurality of first polarizers include at least two different types of polarizers, and the polarization directions of the different types of polarizers are different; in a plane parallel to the driving backplane, the orthographic projections of the different types of polarizers on the driving backplane are arranged alternately.

[0018] In an exemplary embodiment, the plurality of first polarizers include a first type of polarizer, a second type of polarizer, a third type of polarizer and a fourth type of polarizer, and the polarization directions of the first type of polarizer, the second type of polarizer, the third type of polarizer and the fourth type of polarizer intersect with each other; in a plane parallel to the driving backplane, the orthographic projections of the plurality of first type of polarizers on the driving backplane, the orthographic projections of the plurality of second type of polarizers on the driving backplane, the orthographic projections of the plurality of third type of polarizers on the driving backplane and the orthographic projections of the plurality of fourth type of polarizers on the driving backplane are arranged alternately.

[0019] In a second aspect, an embodiment of the present disclosure provides a display device, comprising the display substrate as described above.

[0020] In the third aspect, an embodiment of the present disclosure provides a method for preparing a display substrate, wherein the display substrate includes a stacked light-emitting substrate and a liquid crystal panel, the light-emitting substrate being configured as a backlight source of the liquid crystal panel; in a direction perpendicular to the display substrate, the display substrate also includes a plurality of groups of first polarizers and second polarizers arranged in pairs; the light-emitting substrate includes a driving backplane and a plurality of backlight units arranged on the driving backplane; the method includes: forming the first polarizer in the backlight unit, wherein the polarization directions of the first polarizers in adjacent backlight units intersect in a plane parallel to the display substrate; forming the second polarizer on a side of the first polarizer away from the driving backplane, wherein the polarization directions of the first polarizers and the second polarizers arranged in pairs are parallel.

[0021] The display substrate proposed in the embodiment of the present disclosure has a first polarizer disposed in the backlight unit, and the polarization directions of the first polarizers in adjacent backlight units are different, so that the light emitted from the adjacent backlight units to the liquid crystal panel has different polarization directions. In addition, a second polarizer is disposed on the side of the first polarizer away from the driving backplane, and the polarization directions of the first polarizer and the second polarizer disposed in pairs are parallel, so that even if the light of the backlight unit is incident on the adjacent backlight unit, it will be blocked by the second polarizer disposed correspondingly in the adjacent backlight unit, thereby solving the problem of obvious halo in the display substrate using a backlight source.

[0022] Other aspects will be apparent upon reading and understanding the drawings and detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings are used to provide further understanding of the technical solution of the present disclosure and constitute a part of the specification. Together with the embodiments of the present disclosure, they are used to explain the technical solution of the present disclosure and do not constitute a limitation on the technical solution of the present disclosure.

[0024] Figure 1 is a schematic diagram of a light emitting substrate in some technologies;

[0025] Figure 2 To adopt Figure 1 Schematic diagram of a display substrate in which the light-emitting substrate is used as a backlight source;

[0026] Figure 3 is a schematic diagram of a planar structure of an array substrate;

[0027] Figure 4 It is a structural schematic diagram of a display substrate according to an exemplary embodiment of the present disclosure;

[0028] Figure 5is a schematic diagram of orthographic projection of a plurality of first polarizers on a driving backplane in an exemplary embodiment;

[0029] Figure 6 is a schematic diagram of orthographic projection of a plurality of first polarizers on a driving backplane in yet another exemplary embodiment;

[0030] Figure 7 is a schematic diagram after forming a first planarization layer in an exemplary embodiment;

[0031] Figure 8 is a schematic diagram of a first electrode connection block and a second electrode connection block after forming in an exemplary embodiment;

[0032] Fig. 9 is a schematic diagram of a distributed Bragg reflector after it is formed in an exemplary embodiment;

[0033] Fig.10 is a schematic diagram after forming a first electrode and a second electrode in an exemplary embodiment;

[0034] Fig.11 is a schematic diagram after forming a second planarization layer in an exemplary embodiment;

[0035] Fig.12 is a schematic structural diagram of a display substrate in yet another exemplary embodiment;

[0036] Fig.13 is a schematic structural diagram of a display substrate in yet another exemplary embodiment;

[0037] Fig.14 FIG. 4 is a schematic structural diagram of a display substrate in yet another exemplary embodiment. DETAILED DESCRIPTION

[0038] The embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. Note that the embodiments can be implemented in a plurality of different forms. A person skilled in the art can easily understand the fact that the methods and contents can be transformed into various forms without departing from the purpose and scope of the present disclosure. Therefore, the present disclosure should not be interpreted as being limited to the contents described in the following embodiments. In the absence of conflict, the embodiments in the present disclosure and the features in the embodiments can be arbitrarily combined with each other.

[0039] The proportions of the drawings in this disclosure can be used as a reference in the actual process, but are not limited to this. For example: the width-to-length ratio of the channel, the thickness and spacing of each film layer, the width and spacing of each signal line can be adjusted according to actual needs. The number of pixels in the display backplane and the number of sub-pixels in each pixel are not limited to the numbers shown in the figures. The drawings described in this disclosure are only structural schematic diagrams, and one method of this disclosure is not limited to the shapes or values ​​shown in the drawings.

[0040] In the present specification, ordinal numbers such as “first”, “second” and “third” are provided to avoid confusion among constituent elements, and are not intended to limit the number.

[0041] In this specification, for the sake of convenience, the words and phrases indicating the orientation or positional relationship, such as "middle", "upper", "lower", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., are used to illustrate the positional relationship of the constituent elements with reference to the drawings. This is only for the convenience of describing this specification and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation of the present disclosure. The positional relationship of the constituent elements is appropriately changed according to the direction in which each constituent element is described. Therefore, it is not limited to the words and phrases described in the specification, and can be appropriately replaced according to the situation.

[0042] In this specification, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate, or the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this disclosure can be understood according to specific circumstances.

[0043] In this specification, "electrical connection" includes the case where components are connected together through an element having some electrical function. There is no particular limitation on the "element having some electrical function" as long as it can transmit electrical signals between connected components. Examples of "element having some electrical function" include not only electrodes and wiring, but also switching elements such as transistors, resistors, inductors, capacitors, and other elements having various functions.

[0044] In this specification, "parallel" means a state where the angle formed by two straight lines is greater than -10° and less than 10°, and therefore, also includes a state where the angle is greater than -5° and less than 5°. In addition, "perpendicular" means a state where the angle formed by two straight lines is greater than 80° and less than 100°, and therefore, also includes a state where the angle is greater than 85° and less than 95°.

[0045] The triangles, rectangles, trapezoids, pentagons or hexagons in this specification are not in the strict sense, and may be approximate triangles, rectangles, trapezoids, pentagons or hexagons, etc. There may be some small deformations caused by tolerances, and there may be chamfers, arc edges and deformations.

[0046] The term "about" in the present disclosure refers to a numerical value that is not strictly limited to allow for process and measurement errors.

[0047] Figure 1 Schematic diagram of a light-emitting substrate in some technologies. Figure 1 As shown, the light-emitting substrate may include a driving backplane 1 and a plurality of backlight units disposed on the driving backplane 1. Under the control of the driving backplane 1, the plurality of backlight units may emit light of corresponding brightness. The backlight unit may include a substrate 10 and a light-emitting functional layer 11 disposed on the substrate 10, wherein the substrate 10 is located on a side of the light-emitting functional layer 11 away from the driving backplane 1. In some technologies, the material of the substrate 10 is sapphire, and the thickness of the substrate 10 in a direction perpendicular to the driving backplane 1 is relatively large. The light emitted by the light-emitting functional layer 11 has a large light emission angle after passing through the substrate 10, and the light emitted between adjacent backlight units is prone to crosstalk, which affects the display color gamut of the entire display substrate. Figure 1 The arrows in the figure indicate two light beams emitted by the leftmost backlight unit. The light beams emitted by the leftmost backlight unit can be incident on the backlight unit in the middle, thus affecting the light output of the backlight unit in the middle.

[0048] Figure 2 To adopt Figure 1 The light-emitting substrate shown is a schematic diagram of a display substrate used as a backlight source. Figure 2 As shown, the display substrate includes a light-emitting substrate and a liquid crystal panel. The liquid crystal panel includes an array substrate 21, an opposite substrate 22, and a liquid crystal layer 20 disposed between the array substrate 21 and the opposite substrate 22. The liquid crystal layer 20 includes a plurality of liquid crystal molecules. The display substrate may include a plurality of sub-pixels. A single backlight unit may correspond to a single sub-pixel on the display substrate, so as to control the light emission of a single sub-pixel so that the display substrate forms a display. The substrate 10 of the backlight unit may be located on a side close to the array substrate 21, and the driving backplane 1 may be located on a side away from the array substrate 21. The light emitted by the backlight unit may pass through the substrate 10 and then be incident on the liquid crystal panel. As shown Figure 2 As shown, since the thickness of the substrate 10 in the direction perpendicular to the driving backplane 1 is relatively large, the light emitted by the light-emitting functional layer 11 has a larger light emission angle after passing through the substrate 10. The light emitted by a single backlight unit may be incident on the sub-pixels corresponding to the adjacent backlight units, forming a display halo on the display substrate.

[0049] Figure 3 FIG. 1 is a schematic diagram of a planar structure of an array substrate. Figure 3As shown, in an exemplary embodiment, the array substrate may include a display area AA and a frame area, and the frame area may be arranged on at least one side of the display area AA. In an exemplary embodiment, the frame area may be arranged around the display area AA. The frame area may include a circuit area, and the circuit area may include a first circuit area BB1 and a second circuit area BB2. The first circuit area BB1 may be located on one side of the display area AA along the first direction X. The second circuit area BB2 may be located on the side of the display area AA in the opposite direction of the first direction X. The display area AA may include at least one first signal line extending along the first direction X, and at least one second signal line extending along the second direction Y, the first signal line may be, for example, a gate line, and the second signal line may be, for example, a data line. A first scan driver may be arranged in the first circuit area BB1, and a second scan driver may be arranged in the second circuit area BB2, and the first scan driver and the second scan driver may provide scan signals to the gate lines in the display area AA. The data driver may provide data signals to the data lines in the display area AA.

[0050] In an exemplary embodiment, if Figure 3 As shown, multiple gate lines (S1 to S m ) and multiple data lines (D1 to D n ) can cross-define a plurality of sub-pixel (Pxij) regions, and a pixel electrode, a common electrode, and a driving circuit connected to the pixel electrode are arranged in each sub-pixel region. The driving circuit may include at least one switching unit. Taking the switching unit as a thin film transistor as an example, the drain electrode of the thin film transistor may be electrically connected to the pixel electrode, the source electrode may be electrically connected to the data line, and the gate electrode may be electrically connected to the gate line. The on-off of the thin film transistor is controlled by a scanning signal transmitted by the gate line, and the pixel voltage transmitted on the data line is output to the pixel electrode through the driving circuit.

[0051] In an exemplary embodiment, the opposite substrate 22 may include a color filter layer, and the color filter layer may include color filter units of different colors. In a direction perpendicular to the display substrate, a single color filter unit corresponds to a single sub-pixel region. Under the control of the driving circuit, the liquid crystal molecules of the corresponding sub-pixel are deflected, and the light from the backlight unit of the light-emitting substrate passes through the liquid crystal layer 20 and reaches the corresponding color filter layer, lighting up the corresponding sub-pixel region on the display substrate, so that the display substrate forms a display.

[0052] An embodiment of the present disclosure provides a display substrate, comprising a stacked light-emitting substrate and a liquid crystal panel, wherein the light-emitting substrate is configured as a backlight source of the liquid crystal panel; in a direction perpendicular to the display substrate, the display substrate further comprises a plurality of groups of first polarizers and second polarizers arranged in pairs, wherein the polarization direction of the first polarizers arranged in pairs is parallel to the polarization direction of the second polarizers; the light-emitting substrate comprises a driving backplane and a plurality of backlight units arranged on the driving backplane, wherein the first polarizer is located in the backlight unit, and the second polarizer is located on a side of the first polarizer away from the driving backplane, and in a plane parallel to the display substrate, the polarization directions of the first polarizers in adjacent backlight units intersect.

[0053] The display substrate proposed in the embodiment of the present disclosure has a first polarizer disposed in the backlight unit, and the polarization directions of the first polarizers in adjacent backlight units are different, so that the light emitted from the adjacent backlight units to the liquid crystal panel has different polarization directions. In addition, a second polarizer is disposed on the side of the first polarizer away from the driving backplane, and the polarization directions of the first polarizer and the second polarizer disposed in pairs are parallel, so that even if the light of the backlight unit is incident on the adjacent backlight unit, it will be blocked by the second polarizer disposed correspondingly in the adjacent backlight unit, thereby solving the problem of obvious halo in the display substrate using a backlight source.

[0054] In an exemplary embodiment, the backlight unit includes a substrate, a light-emitting functional layer arranged on the substrate, and a first electrode and a second electrode arranged on the light-emitting functional layer; the first electrode and the second electrode face the driving backplane, the first electrode and the second electrode are electrically connected to the driving backplane respectively, and the light-emitting functional layer is configured to emit light under the action of the voltage of the first electrode and the second electrode.

[0055] In an exemplary embodiment, the light-emitting functional layer includes a first active layer, a quantum well, a second active layer and a current spreading layer arranged in sequence on the substrate; the first electrode is electrically connected to the current spreading layer, and the second electrode is electrically connected to the first active layer.

[0056] In an exemplary embodiment, the first polarizer is located on a side of the current spreading layer away from the substrate; and the second polarizer is located on a side of the substrate away from the light-emitting functional layer.

[0057] In an exemplary embodiment, the display substrate further includes a first flat layer and a second flat layer; the first flat layer is located on a side of the first polarizer away from the substrate, and the orthographic projection of the first flat layer on the substrate covers the orthographic projection of the first polarizer on the substrate; the second flat layer is located on a side of the second polarizer away from the substrate, and the orthographic projection of the second flat layer on the substrate covers the orthographic projection of the second polarizer on the substrate.

[0058] In an exemplary embodiment, the first polarizer is located on a side of the current spreading layer away from the substrate; and the second polarizer is located on a side of the liquid crystal panel away from the light-emitting substrate.

[0059] In an exemplary embodiment, the display substrate further includes a first flat layer and a second flat layer; the first flat layer is located on a side of the first polarizer away from the substrate, and the orthographic projection of the first flat layer on the substrate covers the orthographic projection of the first polarizer on the substrate; the second flat layer is located on a side of the second polarizer away from the liquid crystal panel, and the orthographic projection of the second flat layer on the liquid crystal panel covers the orthographic projection of the second polarizer on the liquid crystal panel.

[0060] In an exemplary embodiment, the first polarizer is located on a side of the substrate away from the light-emitting functional layer; and the second polarizer is located on a side of the liquid crystal panel away from the light-emitting substrate.

[0061] In an exemplary embodiment, the display substrate further includes a first flat layer and a second flat layer; the first flat layer is located on a side of the first polarizer away from the substrate, and the orthographic projection of the first flat layer on the substrate covers the orthographic projection of the first polarizer on the substrate; the second flat layer is located on a side of the second polarizer away from the liquid crystal panel, and the orthographic projection of the second flat layer on the liquid crystal panel covers the orthographic projection of the second polarizer on the liquid crystal panel.

[0062] In an exemplary embodiment, the backlight unit includes a light-emitting functional layer and a first electrode and a second electrode arranged on the light-emitting functional layer; the first electrode and the second electrode face the driving backplane, the first electrode and the second electrode are electrically connected to the driving backplane respectively, and the light-emitting functional layer is configured to emit light under the action of the voltage of the first electrode and the second electrode; the light-emitting functional layer includes a first active layer, a quantum well, a second active layer and a current expansion layer arranged in sequence, and the current expansion layer faces the driving backplane; the first electrode and the current expansion layer are electrically connected, and the second electrode and the first active layer are electrically connected; the first polarizer is located on the side of the first active layer away from the driving backplane; the second polarizer is located on the side of the liquid crystal panel away from the light-emitting substrate.

[0063] In an exemplary embodiment, the first polarizer includes a plurality of mutually parallel first wire grids, and the second polarizer includes a plurality of mutually parallel second wire grids, and the first wire grids of the first polarizer and the second wire grids of the second polarizer arranged in pairs are parallel to each other.

[0064] In an exemplary embodiment, the plurality of first polarizers include at least two different types of polarizers, and the polarization directions of the different types of polarizers are different; in a plane parallel to the driving backplane, the orthographic projections of the different types of polarizers on the driving backplane are arranged alternately.

[0065] In an exemplary embodiment, the plurality of first polarizers include a first type of polarizer and a second type of polarizer, and the polarization direction of the first type of polarizer intersects with the polarization direction of the second type of polarizer; in a plane parallel to the driving backplane, the orthographic projections of the plurality of first type of polarizers on the driving backplane and the orthographic projections of the plurality of second type of polarizers on the driving backplane are arranged alternately.

[0066] In an exemplary embodiment, the plurality of first polarizers include a first type of polarizer, a second type of polarizer, a third type of polarizer and a fourth type of polarizer, and the polarization directions of the first type of polarizer, the second type of polarizer, the third type of polarizer and the fourth type of polarizer intersect with each other; in a plane parallel to the driving backplane, the orthographic projections of the plurality of first type of polarizers on the driving backplane, the orthographic projections of the plurality of second type of polarizers on the driving backplane, the orthographic projections of the plurality of third type of polarizers on the driving backplane and the orthographic projections of the plurality of fourth type of polarizers on the driving backplane are arranged alternately.

[0067] Figure 4 FIG. 1 is a schematic diagram of a display substrate according to an exemplary embodiment of the present disclosure, illustrating the situation of two backlight units. Figure 4As shown, the display substrate includes a stacked light-emitting substrate and a liquid crystal panel, and the light-emitting substrate is set as the backlight source of the liquid crystal panel. The light-emitting substrate includes a driving backplane 1 and a plurality of backlight units arranged on the driving backplane 1. In a direction perpendicular to the display substrate, the display substrate also includes a plurality of groups of first polarizers 106 and second polarizers 113 arranged in pairs, the first polarizer 106 is located in the backlight unit, and the second polarizer 113 is located on the side of the first polarizer 106 away from the driving backplane 1. The polarization direction of the first polarizers 106 arranged in pairs is parallel to the polarization direction of the second polarizer 113. In a direction parallel to the display substrate, the polarization directions of the first polarizers 106 in adjacent backlight units intersect.

[0068] In an exemplary embodiment, a single backlight unit may include a single LED, or a single backlight unit may include two or more adjacent LEDs, and the LEDs may be sub-millimeter LEDs, micro LEDs, etc., which are not limited in the present disclosure.

[0069] In an exemplary embodiment, the first polarizer 106 and the second polarizer 113 may be wire grid polarizers (Wire Grating Polarizer, WGP), such as metal wire grid polarizers, which are not limited in the present disclosure. Since the wire grid polarizer has good light transmittance, by using the wire grid polarizer, it can be ensured that the brightness of the display substrate will not be reduced.

[0070] In an exemplary embodiment, if Figure 4 As shown, a single backlight unit may include a single light-emitting diode, the main structure of the light-emitting diode includes a substrate 10, a light-emitting functional layer arranged on the substrate 10, and a first electrode 111 and a second electrode 112 arranged on the light-emitting functional layer, wherein the substrate 10 serves as a substrate of the light-emitting diode, the first electrode 111 and the second electrode 112 serve as contact electrodes of the light-emitting functional layer, respectively, the first electrode 111 and the second electrode 112 are electrically connected to the driving backplane 1, respectively, and the light-emitting functional layer is used to emit light under the action of the voltage of the first electrode 111 and the second electrode 112.

[0071] In an exemplary embodiment, the light-emitting functional layer includes a first active layer 101, a quantum well 102, a second active layer 103, and a current spreading layer 104, which are sequentially epitaxially grown on a substrate 10. The first active layer 101 as a hole injection layer is disposed on the substrate 10, the quantum well 102 as a light extraction layer is disposed on the first active layer 101, the second active layer 103 as an electron injection layer is disposed on the quantum well 102, and the current spreading layer 104 is disposed on the second active layer 103. The light-emitting functional layer is formed with two high and low step surfaces, the first electrode 111 is disposed on the current spreading layer 104 of the high step surface, and the second electrode 112 is disposed on the first active layer 101 of the low step surface. By providing the current spreading layer 104, the effect of current spreading can be improved, thereby improving the light emitting brightness of the light-emitting diode.

[0072] In an exemplary embodiment, a first electrode connection block 108 is disposed on the high step surface, and the first electrode 111 can be connected to the current spreading layer 104 through the first electrode connection block 108. A second electrode connection block 109 is disposed on the low step surface, and the second electrode 112 can be connected to the first active layer 101 through the second electrode connection block 109.

[0073] In an exemplary embodiment, if Figure 4 As shown, the first polarizer 106 may be located on the side of the current spreading layer 104 away from the substrate 10, and the first polarizer 106 may include a plurality of mutually parallel first wire grids. A first planar layer 107 may be provided on the side of the first polarizer 106 away from the substrate 10, and the orthographic projection of the first planar layer 107 on the substrate 10 may cover the orthographic projections of the plurality of first wire grids on the substrate 10.

[0074] In an exemplary embodiment, if Figure 4 As shown, the second polarizer 113 may be located at a side of the substrate 10 away from the light-emitting functional layer, and the second polarizer 113 may include a plurality of second wire grids parallel to each other, and the first wire grid of the first polarizer 106 and the second wire grid of the second polarizer 113 arranged in pairs are parallel to each other. A second flat layer 114 may be provided at a side of the second polarizer 113 away from the substrate 10, and the orthographic projection of the second flat layer 114 on the substrate 10 may cover the orthographic projections of the plurality of second wire grids on the substrate 10.

[0075] In an exemplary embodiment, if Figure 4As shown, a distributed Bragg reflector (DBR) 110 may be provided on the side of the first flat layer 107 away from the substrate 10, and a first via hole is provided on the distributed Bragg reflector 110, and the first electrode 111 may be connected to the first electrode connection block 108 through the first via hole, and the second electrode 112 may be connected to the second electrode connection block 109 through the first via hole. The distributed Bragg reflector 110 has a periodically stacked superlattice layer, and may be composed of two materials with different refractive indices arranged alternately in an ABAB manner to form a periodic structure. By providing the distributed Bragg reflector 110, the luminous brightness of the backlight unit may be improved.

[0076] In an exemplary embodiment, the material of the distributed Bragg reflector 110 may include silicon oxide, titanium oxide, etc., which is not limited in the present disclosure.

[0077] In an exemplary embodiment, the liquid crystal panel includes an array substrate 21, an opposite substrate 22, and a liquid crystal layer 20 disposed between the array substrate 21 and the opposite substrate 22. The array substrate 21 includes a plurality of sub-pixel regions, and the array substrate 21 in each sub-pixel region is provided with a pixel electrode, a common electrode, and a driving circuit connected to the pixel electrode. The liquid crystal layer 20 includes a plurality of liquid crystal molecules. The opposite substrate 22 includes a color filter layer, and the color filter layer includes color filter units of different colors. In a direction perpendicular to the display substrate, a single color filter unit and a single sub-pixel region are correspondingly arranged. Figure 4 It is shown that the array substrate 21 is arranged on the side close to the light-emitting substrate. In other embodiments, the opposite substrate 22 can also be arranged on the side close to the light-emitting substrate. The present disclosure does not limit the structure of the liquid crystal panel and the positional relationship between the liquid crystal panel and the light-emitting substrate.

[0078] Figure 4, shows a case where the display substrate includes two backlight units, and the polarization directions of the first polarizers of the two backlight units are different. Since the current spreading layer is located on the side close to the driving backplane, by setting the first polarizer on the side of the current spreading layer away from the substrate, the polarization directions of the first polarizers of the adjacent backlight units are different, so that even after the light emitted by the backlight unit is reflected by the driving backplane, the reflected light can still maintain the same polarization direction as the first polarizer of the backlight unit. In addition, by setting the second polarizer on the side of the substrate 10 away from the light-emitting functional layer, and the polarization direction of the first polarizer set in pairs is parallel to the polarization direction of the second polarizer, even if the light of the backlight unit is incident on the adjacent backlight unit, it will be blocked by the second polarizer set in the adjacent backlight unit and will not be emitted from the adjacent backlight unit. Therefore, the light crosstalk and display halo of the display substrate can be reduced. By using a wire grid polarizer, the light crosstalk and display halo of the display substrate can be reduced without reducing the brightness of the display substrate.

[0079] Figure 5 FIG. 1 is a schematic diagram of orthographic projection of a plurality of first polarizers on a driving backplane in an exemplary embodiment. Figure 5 As shown, a plurality of backlight units can be arranged in an array on the driving backplane 1, a single backlight unit is provided with a single first polarizer, and the plurality of first polarizers include a first type polarizer 106A and a second type polarizer 106B, and the polarization direction of the first type polarizer 106A and the polarization direction of the second type polarizer 106B intersect. Along the first direction X, the first type polarizer 106A and the second type polarizer 106B are arranged in an interlaced manner, and along the second direction Y, the first type polarizer 106A and the second type polarizer 106B are arranged in an interlaced manner. The polarization direction of the first polarizer 106 arranged in pairs is parallel to the polarization direction of the second polarizer 113, which will not be described in detail here.

[0080] In an exemplary embodiment, the first type polarizer 106A includes a plurality of mutually parallel first type wire grids, and the second type polarizer 106B includes a plurality of mutually parallel second type wire grids, and the extension direction of the first type wire grids intersects the extension direction of the second type wire grids.

[0081] Figure 6 FIG. 4 is a schematic diagram of orthographic projection of a plurality of first polarizers on a driving backplane in another exemplary embodiment. Figure 6As shown, multiple backlight units can be arranged in an array on the driving backplane 1, and a single first polarizer is provided in a single backlight unit. The multiple first polarizers include a first type polarizer 106A, a second type polarizer 106B, a third type polarizer 106C, and a fourth type polarizer 106D. The polarization directions of the first type polarizer 106A, the second type polarizer 106B, the third type polarizer 106C, and the fourth type polarizer 106D intersect with each other. Figure 6 As shown, in different rows along the first direction X, the first type of polarizer 106A and the second type of polarizer 106B are arranged in an interlaced manner, and the third type of polarizer 106C and the fourth type of polarizer 106D are arranged in an interlaced manner; in different columns along the second direction Y, the first type of polarizer 106A and the third type of polarizer 106C are arranged in an interlaced manner, and the second type of polarizer 106B and the fourth type of polarizer 106D are arranged in an interlaced manner. The first type of polarizer 106A, the second type of polarizer 106B, the third type of polarizer 106C and the fourth type of polarizer 106D can be arranged in other interlaced manners, and the multiple first polarizers can include more different types of polarizers, and the polarization directions of different types of polarizers are different, which is not limited by the present disclosure. The polarization direction of the first polarizer 106 arranged in pairs is parallel to the polarization direction of the second polarizer 113, which will not be repeated here.

[0082] In an exemplary embodiment, the first type of polarizer 106A includes a plurality of mutually parallel first type wire grids, the second type of polarizer 106B includes a plurality of mutually parallel second type wire grids, the third type of polarizer 106C includes a plurality of mutually parallel third type wire grids, and the fourth type of polarizer 106D includes a plurality of mutually parallel fourth type wire grids, and the extension directions of the first type of wire grids, the second type of wire grids, the third type of wire grids, and the fourth type of wire grids intersect in pairs.

[0083] In this embodiment, multiple first polarizers include multiple different types of polarizers, and the polarization directions of different types of polarizers are different. The multiple different types of polarizers are arranged at intervals from each other, so that the anti-crosstalk effect of the display substrate is better, which helps to improve the display quality.

[0084] The preparation process of the display substrate is exemplified below. In this embodiment, growth can be carried out by a metal organic chemical vapor deposition method. The "A and B are arranged in the same layer" mentioned in the present disclosure means that A and B are formed simultaneously through the same patterning process, and the "thickness" of the film layer is the size of the film layer in the direction perpendicular to the substrate. In the exemplary embodiments of the present disclosure, "the orthographic projection of B is within the range of the orthographic projection of A" or "the orthographic projection of A contains the orthographic projection of B" means that the boundary of the orthographic projection of B falls within the boundary of the orthographic projection of A, or the boundary of the orthographic projection of A overlaps with the boundary of the orthographic projection of B.

[0085] To form Figure 4 Taking the display substrate shown as an example, in an exemplary embodiment, the preparation process of the display substrate may include the following steps.

[0086] (1) The first active layer 101 , the quantum well 102 , and the second active layer 103 are sequentially grown on the substrate 10 .

[0087] Subsequently, a current spreading layer 104 is formed on the second active layer 103 to complete the preparation of the light emitting functional layer.

[0088] Subsequently, a first polarizer 106 is formed on the current spreading layer 104 , and the polarization directions of the first polarizers 106 of adjacent light-emitting functional layers intersect.

[0089] Subsequently, a first planarization layer 107 is formed on the first polarizer 106 , and the first planarization layer 107 covers the first polarizer 106 .

[0090] After forming the first planar layer 107, the light emitting diode can be Figure 7 shown.

[0091] In an exemplary embodiment, the material of the substrate 10 may be sapphire; the first active layer 101 is an n-type active layer, and as an electron injection layer, n-type doped gallium nitride may be used; the quantum well 102, as a light-emitting layer of the light-emitting diode, may include multiple periods of alternately grown indium gallium nitride potential well layers and gallium nitride potential barrier layers; the second active layer 25 may be a p-type active layer, and as a hole injection layer, p-type doped gallium nitride may be used. The first polarizer 106 may include a plurality of mutually parallel first wire grids. The first flat layer 107 may be made of an organic material. The material, thickness, process and other parameters of each film layer may be selected as needed, and the present disclosure does not limit this.

[0092] (2) The first flat layer 107, the first polarizer 106, the current spreading layer 104, the second active layer 103, the quantum well 102 and the first active layer 101 are sequentially etched by an etching process, so that the light-emitting functional layer forms two step surfaces, one high and one low. Among them, the first active layer 101, the quantum well 102, the second active layer 103 and the current spreading layer 104 form a higher step surface, and the lower step surface is located in the first active layer 101.

[0093] Subsequently, a first electrode connection block 108 and a second electrode connection block 109 are formed on the two step surfaces of the light-emitting functional layer, wherein the first electrode connection block 108 is located on the high step surface and the second electrode connection block 109 is located on the low step surface. Figure 8 shown.

[0094] (3) A distributed Bragg reflector 110 is formed on the substrate 10 having the aforementioned pattern, and a plurality of first via holes are formed on the distributed Bragg reflector 110, wherein the plurality of first via holes respectively expose the surface of the first electrode connection block 108 and the surface of the second electrode connection block 109. The surface of the distributed Bragg reflector 110 away from the substrate 10 may be parallel to the substrate 10, such as Fig. 9 shown.

[0095] In an exemplary embodiment, the distributed Bragg reflector 110 has a periodically stacked superlattice layer, and can be composed of two materials with different refractive indices arranged alternately in an ABAB manner to form a periodic structure. Suitable materials and the number of alternating periods can be selected as needed, and the present disclosure does not limit this.

[0096] (4) A first electrode 111 and a second electrode 112 are formed on the distributed Bragg reflector 110. The first electrode 111 and the second electrode 112 can be disposed on the same layer, and the first electrode 111 can be connected to the first electrode connection block 108 through a first via hole, and the second electrode 112 can be connected to the second electrode connection block 109 through a first via hole. Fig.10 shown.

[0097] In exemplary embodiments, the first electrode 111 and the second electrode 112 may be a transparent conductive material, which is not limited in the present disclosure.

[0098] (5) A second polarizer 113 is formed on the side of the substrate 10 away from the light-emitting functional layer. The second polarizer 113 may include a plurality of second wire grids parallel to each other. The first wire grids of the first polarizer 106 and the second wire grids of the second polarizer 113 are arranged in pairs and are parallel to each other.

[0099] Subsequently, a second planar layer 114 is formed on a side of the second polarizer 113 away from the substrate 10, and the second planar layer 114 may cover the second polarizer 113. Fig.11 shown.

[0100] (6) The light-emitting diodes are transferred onto the driving backplane 1 to form a light-emitting substrate.

[0101] Subsequently, the light-emitting substrate can be combined with a liquid crystal panel to obtain Figure 4 The display substrate is shown.

[0102] Fig.12 FIG. 1 is a schematic structural diagram of a display substrate in yet another exemplary embodiment, illustrating a situation of two backlight units. Fig.12 Display substrate and Figure 4 The difference between the display substrate and the display substrate is that the positions of the second polarizer 113 and the second flat layer 114 are different. The other structures can refer to the above description. Figure 4The description will not be repeated here.

[0103] In an exemplary embodiment, the second polarizer 113 may be disposed on a side of the opposite substrate 22 of the liquid crystal panel away from the driving backplane 1 , and the second planar layer 114 may be disposed on a side of the second polarizer 113 away from the driving backplane 1 .

[0104] In this embodiment, since the current spreading layer is located on the side close to the driving backplane, by setting the first polarizer on the side of the current spreading layer away from the substrate, the polarization directions of the first polarizers of adjacent backlight units are different, so that even after the light emitted by the backlight unit is reflected by the driving backplane, the reflected light can still maintain the same polarization direction as the first polarizer of the backlight unit. In addition, by setting the second polarizer on the side of the opposite substrate away from the driving backplane, and the polarization direction of the first polarizer and the polarization direction of the second polarizer set in pair are parallel, even if the light of the backlight unit is incident on the sub-pixel corresponding to the adjacent backlight unit, it will be blocked by the second polarizer of the sub-pixel corresponding to the adjacent backlight unit when the light is emitted, and will not be emitted from the sub-pixel corresponding to the adjacent backlight unit, thereby reducing the light crosstalk and display halo of the display substrate. By using a wire grid polarizer, the light crosstalk and display halo of the display substrate can be reduced without reducing the brightness of the display substrate.

[0105] Fig.12 The preparation process of the display substrate can refer to the above Figure 4 The description of the substrate preparation process is shown in FIG.

[0106] Fig.13 FIG. 1 is a schematic structural diagram of a display substrate in yet another exemplary embodiment, illustrating a situation of two backlight units. Fig.13 Display substrate and Fig.12 The difference between the display substrate and the display substrate is that the positions of the first polarizer 106 and the first flat layer 107 are different. The other structures can refer to the above description. Fig.13 The description will not be repeated here.

[0107] In an exemplary embodiment, the first polarizer 106 may be disposed on a side of the substrate 10 away from the light emitting functional layer, and the first planarization layer 107 may be disposed on a side of the first polarizer 106 away from the light emitting functional layer.

[0108] In this embodiment, since the substrate 10 is located on the side close to the liquid crystal panel, by arranging the first polarizer on the side of the substrate 10 away from the light-emitting functional layer, the polarization directions of the first polarizers of the adjacent backlight units are different, so that no matter which direction the light enters the present backlight unit, after entering the liquid crystal panel from the corresponding position of the present backlight unit, the polarization direction of the light is the same as the polarization direction of the first polarizer of the present backlight unit. This arrangement enables the present backlight unit to make full use of the light emitted from the adjacent backlight unit, which can not only solve the light crosstalk of the display substrate, but also improve the light utilization rate of the display substrate. By arranging the second polarizer on the side of the opposite substrate away from the driving backplane, and the polarization direction of the first polarizer arranged in pairs is parallel to the polarization direction of the second polarizer, it can be ensured that the polarization direction of the light incident on the present sub-pixel is the same as the polarization direction of the second polarizer of the present sub-pixel when it is emitted, so that the display halo of the display substrate can be reduced. By using a wire grid polarizer, the light crosstalk and display halo of the display substrate can be reduced without reducing the brightness of the display substrate.

[0109] Fig.13 The preparation process of the display substrate can refer to the above Fig.12 The description of the substrate preparation process is shown in FIG.

[0110] Fig.14 FIG. 1 is a schematic structural diagram of a display substrate in yet another exemplary embodiment, illustrating a situation of two backlight units. Fig.14 Display substrate and Fig.13 The difference between the display substrate and Fig.14 The display substrate in the embodiment is stripped of the substrate 10, and the first polarizer 106 is directly formed on the first active layer 101. The other structures can refer to the above description. Fig.13 The description will not be repeated here.

[0111] In this embodiment, by stripping the substrate, the first polarizer is directly arranged on the side of the first active layer 101 away from the light-emitting functional layer, and the light does not need to pass through the substrate before entering the liquid crystal panel. The optical path of the light incident on the liquid crystal panel is smaller, and the light output angle of a single backlight unit can be reduced, so that the light emitted by a single backlight unit is more concentrated, which can not only reduce the probability of light crosstalk between adjacent backlight units, but also improve the utilization rate of light by the display substrate, and can also reduce the thickness of the display substrate, which is conducive to realizing the thinness of the display substrate. Since the first active layer is located on the side close to the liquid crystal panel, by directly forming the first polarizer on the first active layer, the polarization direction of the first polarizer in the adjacent backlight unit is different, so that no matter which direction the light enters the backlight unit, after entering the liquid crystal panel from the corresponding position of the backlight unit, the polarization direction of the light is the same as the polarization direction of the first polarizer. This arrangement allows the backlight unit to make full use of the light emitted from the adjacent backlight unit, which can not only solve the light crosstalk of the display substrate, but also improve the light utilization rate of the display substrate. By arranging a second polarizer on the side of the opposite substrate away from the driving backplane, and arranging the polarization direction of the first polarizer and the polarization direction of the second polarizer arranged in pair to be parallel, it can be ensured that the polarization direction of the light incident on the sub-pixel is the same as the polarization direction of the second polarizer of the sub-pixel when it is emitted, so that the display halo of the display substrate can be reduced. By using a wire grid polarizer, the light crosstalk and display halo of the display substrate can be reduced without reducing the brightness of the display substrate.

[0112] Fig.14 The preparation process of the display substrate can refer to the above Fig.13 The description of the substrate preparation process is shown in FIG.

[0113] It should be noted that the above-described embodiments or implementations are merely illustrative and not restrictive. Therefore, the present disclosure is not limited to what is specifically shown and described herein. Various modifications, substitutions, or omissions may be made to the forms and details of the implementations without departing from the scope of the present disclosure. For example, Figure 4 , Fig.12 The display substrate shown in the figure can also be peeled off the substrate, and the structures and features shown in the above embodiments can be arbitrarily combined as needed, and the present disclosure does not limit this.

[0114] The present disclosure also provides a display device, including the display substrate described above. The display device can be any product or component with a display function, such as an LCD display, a mobile phone, a tablet computer, a television, a monitor, a notebook computer, a digital photo frame, a navigator, etc., but the present disclosure is not limited thereto.

[0115] The embodiment of the present disclosure also provides a method for preparing a display substrate, wherein the display substrate includes a stacked light-emitting substrate and a liquid crystal panel, wherein the light-emitting substrate is configured as a backlight source of the liquid crystal panel; in a direction perpendicular to the display substrate, the display substrate also includes a plurality of groups of first polarizers and second polarizers arranged in pairs; the light-emitting substrate includes a driving backplane and a plurality of backlight units arranged on the driving backplane; the method includes: forming the first polarizer in the backlight unit, wherein the polarization directions of the first polarizers in adjacent backlight units intersect in a plane parallel to the display substrate; and forming the second polarizer on a side of the first polarizer away from the driving backplane, wherein the polarization directions of the first polarizers and the second polarizers arranged in pairs are parallel.

[0116] Although the embodiments disclosed in the present invention are as above, the contents described are only embodiments adopted to facilitate understanding of the present invention and are not intended to limit the present invention. Any technician in the field to which the present invention belongs can make any modifications and changes in the form and details of implementation without departing from the spirit and scope disclosed in the present invention, but the patent protection scope of the present invention shall still be subject to the scope defined in the attached claims.

Claims

1. A display substrate, characterized in that: The invention comprises a stacked light-emitting substrate and a liquid crystal panel, wherein the light-emitting substrate is arranged as a backlight source of the liquid crystal panel; in a direction perpendicular to the display substrate, the display substrate further comprises a plurality of groups of first polarizers and second polarizers arranged in pairs, wherein the polarization directions of the first polarizers arranged in pairs are parallel to the polarization directions of the second polarizers; The light-emitting substrate includes a driving backplane and a plurality of backlight units arranged on the driving backplane, the first polarizer is located in the backlight unit, the second polarizer is located on a side of the first polarizer away from the driving backplane, and in a plane parallel to the display substrate, the polarization directions of the first polarizers in adjacent backlight units intersect.

2. The display substrate according to claim 1, characterized in that: The backlight unit includes a substrate, a light-emitting functional layer arranged on the substrate, and a first electrode and a second electrode arranged on the light-emitting functional layer; the first electrode and the second electrode face the driving backplane, the first electrode and the second electrode are electrically connected to the driving backplane respectively, and the light-emitting functional layer is configured to emit light under the action of the voltage of the first electrode and the second electrode.

3. The display substrate according to claim 2, characterized in that: The light-emitting functional layer includes a first active layer, a quantum well, a second active layer and a current spreading layer which are sequentially arranged on the substrate; the first electrode is electrically connected to the current spreading layer, and the second electrode is electrically connected to the first active layer.

4. The display substrate according to claim 3, characterized in that: The first polarizer is located at a side of the current spreading layer away from the substrate; the second polarizer is located at a side of the substrate away from the light-emitting functional layer.

5. The display substrate according to claim 4, characterized in that: The display substrate further includes a first flat layer and a second flat layer; the first flat layer is located on a side of the first polarizer away from the substrate, and the orthographic projection of the first flat layer on the substrate covers the orthographic projection of the first polarizer on the substrate; the second flat layer is located on a side of the second polarizer away from the substrate, and the orthographic projection of the second flat layer on the substrate covers the orthographic projection of the second polarizer on the substrate.

6. The display substrate according to claim 3, characterized in that: The first polarizer is located at a side of the current spreading layer away from the substrate; the second polarizer is located at a side of the liquid crystal panel away from the light-emitting substrate.

7. The display substrate according to claim 6, characterized in that: The display substrate also includes a first flat layer and a second flat layer; the first flat layer is located on a side of the first polarizer away from the substrate, and the orthographic projection of the first flat layer on the substrate covers the orthographic projection of the first polarizer on the substrate; the second flat layer is located on a side of the second polarizer away from the liquid crystal panel, and the orthographic projection of the second flat layer on the liquid crystal panel covers the orthographic projection of the second polarizer on the liquid crystal panel.

8. The display substrate according to claim 3, characterized in that: The first polarizer is located on a side of the substrate away from the light-emitting functional layer; the second polarizer is located on a side of the liquid crystal panel away from the light-emitting substrate.

9. The display substrate according to claim 8, characterized in that: The display substrate also includes a first flat layer and a second flat layer; the first flat layer is located on a side of the first polarizer away from the substrate, and the orthographic projection of the first flat layer on the substrate covers the orthographic projection of the first polarizer on the substrate; the second flat layer is located on a side of the second polarizer away from the liquid crystal panel, and the orthographic projection of the second flat layer on the liquid crystal panel covers the orthographic projection of the second polarizer on the liquid crystal panel.

10. The display substrate according to claim 1, characterized in that: The backlight unit comprises a light-emitting functional layer and a first electrode and a second electrode arranged on the light-emitting functional layer; the first electrode and the second electrode face the driving backplane, the first electrode and the second electrode are electrically connected to the driving backplane respectively, and the light-emitting functional layer is configured to emit light under the voltage of the first electrode and the second electrode; The light-emitting functional layer comprises a first active layer, a quantum well, a second active layer and a current expansion layer which are arranged in sequence, and the current expansion layer faces the driving backplane; the first electrode is electrically connected to the current expansion layer, and the second electrode is electrically connected to the first active layer; The first polarizer is located on a side of the first active layer away from the driving backplane; the second polarizer is located on a side of the liquid crystal panel away from the light-emitting substrate.

11. The display substrate according to claim 1, characterized in that: The first polarizer includes a plurality of first wire grids parallel to each other, and the second polarizer includes a plurality of second wire grids parallel to each other. The first wire grids of the first polarizer and the second wire grids of the second polarizer, which are arranged in pairs, are parallel to each other.

12. The display substrate according to claim 1, characterized in that: The plurality of first polarizers include at least two different types of polarizers, and the polarization directions of the different types of polarizers are different; in a plane parallel to the driving backplane, the orthographic projections of the different types of polarizers on the driving backplane are arranged alternately.

13. The display substrate according to claim 12, characterized in that: The multiple first polarizers include a first type of polarizer, a second type of polarizer, a third type of polarizer and a fourth type of polarizer, and the polarization directions of the first type of polarizer, the second type of polarizer, the third type of polarizer and the fourth type of polarizer intersect with each other; in a plane parallel to the driving backplane, the orthographic projections of the multiple first type of polarizers on the driving backplane, the orthographic projections of the multiple second type of polarizers on the driving backplane, the orthographic projections of the multiple third type of polarizers on the driving backplane and the orthographic projections of the multiple fourth type of polarizers on the driving backplane are arranged in an interlaced manner.

14. A display device, characterized in that: The display substrate comprises the display substrate as claimed in any one of claims 1 to 13.

15. A method for preparing a display substrate, characterized in that: The display substrate comprises a stacked light-emitting substrate and a liquid crystal panel, wherein the light-emitting substrate is provided as a backlight source of the liquid crystal panel; in a direction perpendicular to the display substrate, the display substrate further comprises a plurality of groups of first polarizers and second polarizers provided in pairs; The light-emitting substrate includes a driving backplane and a plurality of backlight units arranged on the driving backplane; the method includes: forming the first polarizer in the backlight unit, wherein the polarization directions of the first polarizers in adjacent backlight units intersect in a plane parallel to the display substrate; The second polarizer is formed on a side of the first polarizer away from the driving backplane, and the polarization direction of the first polarizer and the polarization direction of the second polarizer arranged in pair are parallel.

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