Display substrate, preparation method thereof and display device

Abstract

The invention relates to the technical field of display equipment, and discloses a display substrate, a preparation method thereof and a display device.The display equipment comprises a substrate body, a first electrode, a second electrode, a first electrode and a second electrode, the black matrix is located on the first side face of the substrate, the black matrix is provided with a plurality of openings, the black matrix comprises a first light shielding layer and a second light shielding layer which are sequentially arranged in a stacked mode in the first direction, the first light shielding layer is made of metal materials, and the second light shielding layer is made of metal semiconductor oxide materials; the first direction is the direction from the second side to the first side. The display equipment is favorable for realizing high resolution, and meanwhile, the reflectivity of the black matrix can be obviously reduced, and the display effect is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of display equipment, and in particular to a display substrate, a preparation method thereof and a display device. Background Art

[0002] At present, in the field of consumer-level VR products, liquid crystal display (LCD) screens still occupy a mainstream position, mainly due to their following four advantages: (1) high quality, no flicker, no screen flicker, and better eye protection; (2) good picture effect, no deformation, and mature technology; (3) high clarity, low energy consumption, and perfect image signal; (4) low cost; However, in order to avoid dizziness and reduce the "screen door effect" as much as possible, the screen resolution needs to be increased as much as possible;

[0003] One of the major reasons that restrict the resolution of liquid crystal display products is the size of the black matrix (BM). The basic function of the black matrix in the color film substrate is to block light, which is used to improve the contrast of the TFT-LCD liquid crystal display screen, avoid color mixing of connected color layers, and reduce external light reflection. The use of the black matrix can effectively block the light leakage between sub-pixels. To obtain a good light-shielding effect, the black matrix must have a smaller reflectivity. In the prior art, the black matrix uses a resin BM because the resin BM has low cost and low reflectivity, and the reflected light will not be blue or red. However, in order to improve the contrast of TFT-LCD, in addition to reducing the reflectivity of the black matrix, it is also necessary to strengthen the dimensional accuracy management to prevent light leakage caused by fitting deviation. Due to its material limitations, the size of the traditional resin BM is difficult to be reduced, which limits the development of high-resolution TFT-LCD products. Summary of the invention

[0004] The present invention provides a display substrate, a manufacturing method thereof and a display device. The display substrate is conducive to achieving high resolution and can significantly reduce the reflectivity of a black matrix and improve the display effect.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] A display substrate, comprising:

[0007] A substrate having a first side surface and a second side surface opposite to each other;

[0008] A black matrix, wherein the black matrix is ​​located on the first side of the base substrate, the black matrix has a plurality of openings, the black matrix comprises a first light-shielding layer and a second light-shielding layer sequentially stacked along a first direction, the material of the first light-shielding layer is a metal material, the material of the second light-shielding layer is a metal semiconductor oxide material, and the first direction is the direction in which the second side points to the first side.

[0009] Optionally, the first light-shielding layer includes at least two metal layers stacked in sequence along the first direction.

[0010] Optionally, the first light-shielding layer includes a first supporting metal layer, an intermediate metal layer, and a second supporting metal layer stacked in sequence along a first direction, the first supporting metal layer and the second supporting metal layer have stronger corrosion resistance than the intermediate metal layer, and the hardness of the first supporting metal layer and the second supporting metal layer is greater than the hardness of the intermediate metal layer.

[0011] Optionally, the first supporting metal layer and the second supporting metal layer are made of titanium, and the intermediate metal layer is made of aluminum.

[0012] Optionally, the first supporting metal layer and the second supporting metal layer have a film thickness of 50 angstroms to 1000 angstroms along the first direction, and the intermediate metal layer has a film thickness of 500 angstroms to 8000 angstroms along the first direction.

[0013] Optionally, the second light-shielding layer includes at least two film layers sequentially arranged along the first direction.

[0014] Optionally, a material of the second light-shielding layer is at least one of indium tin oxide, indium zinc oxide and indium gallium zinc oxide.

[0015] Optionally, a film thickness of the second light-shielding layer along the first direction is 500 angstroms to 3000 angstroms.

[0016] Optionally, it further includes a filter layer located on a side of the black matrix away from the base substrate and a passivation layer located on a side of the filter layer away from the base substrate.

[0017] Optionally, it further includes an electrode layer located on a side of the passivation layer away from the substrate.

[0018] Optionally, a shielding layer is further included on the second side of the substrate, and the shielding layer is used to shield interference from external electric fields.

[0019] The present invention also provides a display device, comprising any one of the display substrates provided in the above technical solutions.

[0020] The present invention also provides a method for preparing a display substrate, comprising:

[0021] Forming a first light shielding layer on the first side surface of the base substrate, wherein the material of the first light shielding layer is a metal material;

[0022] A second light shielding layer is formed on a side of the first light shielding layer away from the base substrate. The material of the second light shielding layer is a metal semiconductor oxide. The second light shielding layer and the first light shielding layer together form a black matrix. The black matrix has a plurality of openings.

[0023] Optionally, after forming the first light shielding layer on the first side of the substrate, the method further comprises:

[0024] patterning the first light shielding layer by a dry etching process;

[0025] After forming the second light shielding layer on the side of the first light shielding layer away from the base substrate, the method comprises:

[0026] The second light shielding layer is patterned by a wet etching process.

[0027] Optionally, after forming the second light shielding layer on the side of the first light shielding layer facing away from the base substrate, the method further comprises:

[0028] The first light shielding layer and the second light shielding layer are patterned by a dry etching process.

[0029] The present invention provides a display substrate, a preparation method thereof and a display device. The display substrate comprises a base substrate and a black matrix. The black matrix is ​​located on a first side of the base substrate. The black matrix has a plurality of openings. The black matrix comprises a first light-shielding layer and a second light-shielding layer which are sequentially stacked on the base substrate. The material of the first light-shielding layer may be a metal material, and the material of the second light-shielding layer may be a metal semiconductor oxide. The shape and size of the black matrix can be precisely controlled, which is conducive to achieving high resolution. At the same time, since the second light-shielding layer is arranged on a side of the first light-shielding layer away from the base substrate, the first light-shielding layer and the second light-shielding layer have different refractive indices for light. Under the action of the second light-shielding layer, most of the light incident on the black matrix will be absorbed by the first light-shielding layer, which can significantly reduce the reflectivity of the black matrix. The black matrix has a better light-shielding effect, which is conducive to improving the contrast and picture quality when displaying pictures, and can improve the display effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a curve diagram showing the relationship between the black matrix film thickness and the reflectivity in the related art;

[0031] Figure 2 A schematic structural diagram of a display substrate provided by an embodiment of the present invention;

[0032] Figure 3 A schematic structural diagram of a first light-shielding layer provided in an embodiment of the present invention;

[0033] Figure 4 A schematic structural diagram of a display substrate provided by an embodiment of the present invention;

[0034] Figure 5 A schematic structural diagram of a display substrate provided by an embodiment of the present invention;

[0035] Figure 6 A fitting curve of the film thickness and reflectivity of the second light-shielding layer provided in an embodiment of the present invention;

[0036] Figure 7 A flow chart of a method for preparing a display substrate provided by an embodiment of the present invention;

[0037] Figure 8 and Fig. 9 A schematic diagram of a black matrix manufacturing process provided by an embodiment of the present invention;

[0038] Fig.10 A schematic diagram of a black matrix manufacturing process provided by an embodiment of the present invention.

[0039] icon:

[0040] 1-substrate substrate; 2-black matrix; 21-first light-shielding layer; 211-first supporting metal layer; 212-intermediate metal layer; 213-second supporting metal layer; 22-second light-shielding layer; 3-filter layer; 31-red color resistance; 32-green color resistance; 33-blue color resistance; 4-passivation layer; 5-electrode layer; 6-spacer; 7-shielding layer. DETAILED DESCRIPTION

[0041] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0042] In the related art, in order to improve the resolution of the display panel, a black matrix made of metal materials can be used instead of a black matrix made of organic materials. For example, a black matrix made of metal material molybdenum (Mo) can more finely control the shape of the metal and reduce the size, so that the black matrix is ​​smaller and thinner, thereby achieving high resolution and helping to improve the aperture ratio. However, the black matrix made of metal materials has a high reflectivity to light, which will affect the contrast of the display panel and the display effect of the display panel.

[0043] In practical applications, when the material of the black matrix is ​​molybdenum, such as Figure 1 The figure shows the relationship between the reflectivity of the black matrix and the thickness of the black matrix, wherein curve A is the relationship between the thickness and reflectivity of the black matrix of the metal material before annealing, and curve B is the relationship between the thickness and reflectivity of the black matrix of the metal material after annealing. Figure 1It can be seen that when the film thickness of the black matrix is ​​thin, for example, when the film thickness of the black matrix is ​​500 angstroms, the reflectivity is high, above 60%, which will affect the display effect.

[0044] In order to solve the above technical problems, an embodiment of the present invention provides a display substrate, such as Figure 2 As shown, including:

[0045] A substrate 1, wherein the substrate 1 has a first side surface and a second side surface opposite to each other;

[0046] Black matrix 2, the black matrix 2 is located on the first side of the base substrate 1, the black matrix 2 has a plurality of openings, the black matrix 2 includes a first light-shielding layer 21 and a second light-shielding layer 22 stacked in sequence along a first direction, the material of the first light-shielding layer 21 is a metal material, the material of the second light-shielding layer 22 is a metal semiconductor oxide material, and the first direction is the direction from the second side to the first side.

[0047] The display substrate provided in the embodiment of the present invention includes a base substrate 1 and a black matrix 2. The black matrix 2 is located on the first side of the base substrate 1. The black matrix 2 has multiple openings. The black matrix 2 includes a first light-shielding layer 21 and a second light-shielding layer 22 which are sequentially stacked on the base substrate 1. The material of the first light-shielding layer 21 can be a metal material, and the material of the second light-shielding layer 22 can be a metal semiconductor oxide. The shape and size of the black matrix 2 can be accurately controlled, which is conducive to achieving high resolution. At the same time, since the second light-shielding layer 22 is arranged on the side of the first light-shielding layer 21 away from the base substrate 1, the first light-shielding layer 21 and the second light-shielding layer 22 have different refractive indices for light. Under the action of the second light-shielding layer 22, most of the light incident on the black matrix 2 will be absorbed by the first light-shielding layer 21, which can significantly reduce the reflectivity of the black matrix 2 and has a better light-shielding effect, which is conducive to improving the contrast and picture quality when displaying the picture, and can improve the display effect.

[0048] Specifically, the display substrate may be a color film substrate in a liquid crystal display panel.

[0049] In the embodiment of the present invention, the first light shielding layer 21 may have only one metal layer. For example, the material of the first light shielding layer 21 may be aluminum (Al) or molybdenum (Mo), etc., or other metal materials, which are not limited here.

[0050] Optionally, the first light-shielding layer 21 may also include at least two metal layers stacked in sequence along the first direction. The stacked arrangement of the first light-shielding layer 21 is conducive to accurately controlling the film thickness of the first light-shielding layer 21, and is conducive to achieving high resolution. For example, the first light-shielding layer 21 may include a first metal layer and a second metal layer stacked in sequence along the first direction; the material of the first metal layer may be aluminum (Al), and the material of the second metal layer may be titanium (Ti); or the material of the first metal layer is titanium (Ti), and the material of the second metal layer is aluminum (Al). Specifically, the number of metal layers in the first light-shielding layer 21 and the materials of each metal layer are not limited here and can be determined according to actual conditions.

[0051] In the above invention embodiments, Figure 3 As shown, the first light-shielding layer 21 may also include a first supporting metal layer 211, an intermediate metal layer 212, and a second supporting metal layer 213 which are sequentially stacked along a first direction. The corrosion resistance of the first supporting metal layer 211 and the second supporting metal layer 213 is stronger than that of the intermediate metal layer 212. The hardness of the first supporting metal layer 211 and the second supporting metal layer 213 is greater than that of the intermediate metal layer 212. The first supporting metal layer 211 and the second supporting metal layer 213 can protect the intermediate metal layer 212 from corrosion and deformation, thereby increasing the service life of the black matrix 2.

[0052] Specifically, the material of the first supporting metal layer 211 and the second supporting metal layer 213 may be titanium, and the material of the intermediate metal layer 212 may be aluminum. Titanium has better corrosion resistance and hardness than aluminum. The first supporting metal layer 211 and the second supporting metal layer 213 made of titanium can protect the intermediate metal layer 212 made of aluminum from corrosion, blistering and other problems. Optionally, the material of the first supporting metal layer 211 and the second supporting metal layer 213 may also be molybdenum, and the material of the intermediate metal layer 212 may be aluminum. The materials of the first supporting metal layer 211, the intermediate metal layer 212 and the second supporting metal layer 213 are not limited here and can be determined according to actual conditions.

[0053] Specifically, the thickness of the first supporting metal layer 211 and the second supporting metal layer 213 along the first direction may be 50 angstroms to 1000 angstroms, and the thickness of the intermediate metal layer 212 along the first direction may be 500 angstroms to 8000 angstroms, which is not limited here and depends on actual conditions.

[0054] In the embodiment of the present invention, the second shading layer 22 may include only one layer; or the second shading layer 22 may include at least two film layers sequentially arranged along the first direction, which is not limited here and depends on actual conditions.

[0055] Specifically, the material of the second light shielding layer 22 can be at least one of indium tin oxide (ITO), indium zinc oxide (IZO), indium gallium zinc oxide (IGZO), etc. The refractive index of the ITO material is between 1.8 and 2.1, and decreases slightly with the increase of the film thickness, the refractive index of the IZO material is about 2.05, and the refractive index of the IGZO material is about 1.9.

[0056] Specifically, if the second light shielding layer 22 has only one film layer, the material of the second light shielding layer 22 can be any one of indium tin oxide, indium zinc oxide and indium gallium zinc oxide, or if the second light shielding layer 22 has two film layers, the material of one film layer can be indium tin oxide, and the material of the other film layer can be indium zinc oxide. Specifically, the material of the first light shielding layer 21 is not limited here and can be determined according to actual conditions.

[0057] The thickness of the second light shielding layer 22 along the first direction may be 500 angstroms to 3000 angstroms, which is not limited here and depends on actual conditions.

[0058] In the embodiment of the present invention, Figure 1 As shown, the display substrate may further include a filter layer 3 located on the side of the black matrix 2 facing away from the base substrate 1 and a passivation layer 4 located on the side of the filter layer 3 facing away from the base substrate 1. The filter layer 3 has a plurality of color resists corresponding to the plurality of openings on the black matrix 2, and the filter layer 3 may have three color resists of different colors, for example, a red color resist 31, a green color resist 32, and a blue color resist 33.

[0059] Specifically, in this embodiment, the black matrix 2 can (1) separate the color resistance in the filter layer 3 to improve the contrast and prevent color mixing and cross-color between pixels when the display panel is displayed; (2) shield the light leakage of the backlight source outside the opening part; (3) prevent light from causing changes in the characteristics and working parameters of the thin film transistor; (4) prevent external ambient light from affecting the display contrast.

[0060] In the embodiment of the present invention, the display substrate may be a color film substrate of a TN / PVA type liquid crystal display panel, such as Figure 4 As shown, the display substrate may further include an electrode layer 5 located on the side of the passivation layer 4 away from the base substrate 1 , and the material of the electrode layer 5 may be ITO.

[0061] In the embodiment of the present invention, the display substrate may also be a color film substrate of an ADS / IPS type liquid crystal display panel, such as Figure 5 As shown, the display substrate may further include a shielding layer 7 located on the second side of the base substrate 1, the shielding layer 7 is used to shield the interference of the external electric field on the liquid crystal and improve the display effect. The material of the shielding layer 7 may be ITO.

[0062] Specifically, Figure 2 , Figure 4 and Figure 5 As shown, the display substrate may further include a plurality of spacers 6 located on the side of the passivation layer 4 away from the base substrate 1 , and the orthographic projection of the spacers 6 on the base substrate 1 may be located within the orthographic projection of the black matrix 2 on the base substrate 1 .

[0063] In the actual application of the present application, the first light-shielding layer 21 of the black matrix 2 may include a first supporting metal layer 211, an intermediate metal layer 212, and a second supporting metal layer 213 which are sequentially stacked along a first direction. The materials of the first supporting metal layer 211, the intermediate metal layer 212, and the second supporting metal layer 213 may be Ti, Al, and Ti, respectively. The film thicknesses of the first supporting metal layer 211, the intermediate metal layer 212, and the second supporting metal layer 213 may be 500 angstroms, 4000 angstroms, and 500 angstroms, respectively. The material of the second light-shielding layer 22 may be ITO, and the film thickness of the second light-shielding layer 22 may be 700 angstroms. The reflectivity of the first light-shielding layer 21 is about 60%. After the second light-shielding layer 22 is arranged on the side of the first light-shielding layer 21 away from the base substrate 1, the reflectivity of the black matrix 2 to light may become about 20%, which is significantly reduced.

[0064] Table 1 shows the measurement results of the initial reflectivity when the black matrix 2 has only the first shading layer 21 and the first shading layer 21 has different film thicknesses, wherein the film thickness D of the first shading layer 21 = the film thickness d1 of the first supporting metal layer + the film thickness d2 of the intermediate metal layer + the film thickness d3 of the second supporting metal layer. It can be seen from Table 1 that as the film thickness of the first shading layer increases or decreases, the initial reflectivity does not change significantly and is always around 60%.

[0065] Table 1

[0066] D=d1+d2+d3(angstrom) Reflectivity(%) 500+2000+500 59.9、60.0 500+4000+500 60.0、59.9 500+6500+500 60.5、60.5

[0067] Table 2 shows the change in reflectivity when the black matrix 2 has a first shading layer 21 and a second shading layer 22, with different film thicknesses of the first shading layer 21 and different film thicknesses of the second shading layer 22, wherein d4 is the thickness of the second shading layer 22. It can be seen from Table 2 that when the thickness of the first shading layer 21 is different and the thickness of the second shading layer 22 is the same, the reflectivity of the black matrix 2 is almost at the same level; and for the first shading layer 21 at various film thicknesses, as the thickness of the second shading layer 22 decreases, the reflectivity shows an obvious downward trend; for example, when the thickness of the second shading layer 22 is 400 angstroms, the reflectivity is reduced by about 75%, which is conducive to the production of a thinner black matrix 2 film layer.

[0068] Table 2

[0069]

[0070] like Figure 6 The figure shows the fitting curve of the second light shielding layer 22 and the reflectivity. It can be seen that the thinner the second light shielding layer 22 is, the more obvious the effect of reducing the reflectivity of the black matrix 2 is.

[0071] An embodiment of the present invention further provides a display device, comprising any one of the display substrates provided in the above technical solutions.

[0072] The present invention also provides a method for preparing a display substrate. Figure 7 As shown, including:

[0073] S701: forming a first light shielding layer on a first side surface of the base substrate, wherein the material of the first light shielding layer is a metal material;

[0074] S702: forming a second light shielding layer on a side of the first light shielding layer away from the base substrate, wherein the material of the second light shielding layer is a metal semiconductor oxide, and the second light shielding layer and the first light shielding layer together form a black matrix, and the black matrix has a plurality of openings.

[0075] In the preparation method of the display substrate provided by the embodiment of the present invention, first, a first light-shielding layer is formed on the first side of the base substrate, and the material of the first light-shielding layer can be a metal material. Then, a second light-shielding layer is formed on the side of the first light-shielding layer away from the base substrate, and the material of the second light-shielding layer is a metal semiconductor oxide. The second light-shielding layer and the first light-shielding layer together constitute a black matrix. When the first light-shielding layer and the second light-shielding layer are manufactured, the shape and size of the black matrix can be precisely controlled, which is conducive to achieving high resolution. At the same time, since the second light-shielding layer is arranged on the side of the first light-shielding layer away from the base substrate, the first light-shielding layer and the second light-shielding layer have different refractive indices for light. Under the action of the second light-shielding layer, most of the light incident on the black matrix will be absorbed by the first light-shielding layer, which can significantly reduce the reflectivity of the black matrix, has a better light-shielding effect, is conducive to improving the contrast and picture quality when displaying the picture, and can improve the display effect.

[0076] In the preparation method provided by the embodiment of the present invention, after forming the first light shielding layer on the first side of the substrate in step S701, the following steps are included: S7011: patterning the first light shielding layer by dry etching. This method can make the line width of the patterned first light shielding layer smaller and the pattern more refined;

[0077] After forming a second light shielding layer on the side of the first light shielding layer away from the substrate in step S702, Figure 8 As shown, the following steps are included: S7021: patterning the second light shielding layer by a wet etching process, such as Fig. 9This step can use the same mask plate as that used in step S7011. Although wet etching is used at this time, the deviation of the second light shielding layer during wet etching is small, and the line width of the patterned second light shielding layer can also be very small (about 1 micron), which is conducive to the preparation of a small-sized black matrix.

[0078] Optionally, after forming a second light shielding layer on the side of the first light shielding layer away from the substrate in step S702, Fig.10 As shown, the following steps may be specifically included: patterning the first light shielding layer and the second light shielding layer by dry etching process, such as Fig. 9 That is, the first light shielding layer and the second light shielding layer are deposited at one time and patterned at the same time, which can simplify the manufacturing process and save the manufacturing cost.

[0079] In the preparation method provided by the embodiment of the present invention, after the black matrix is ​​formed in step S702, the method further includes: forming a filter layer on the side of the black matrix away from the base substrate; forming a passivation layer on the side of the filter layer away from the base substrate, such as Figure 2 shown.

[0080] In the preparation method provided by the embodiment of the present invention, after step S702, the following steps are further included: S703 forms a plurality of spacers on the side of the passivation layer away from the base substrate, and the orthographic projection of the spacers on the base substrate can be located within the orthographic projection of the black matrix on the base substrate, such as Figure 4 shown.

[0081] In the preparation method provided in the embodiment of the present invention, if the display substrate to be manufactured is a color filter substrate of a TN / PVA type liquid crystal display panel, after step S703, the following steps are further included: forming an electrode layer on the side of the passivation layer away from the base substrate, and the material of the electrode layer can be ITO, such as Figure 4 shown.

[0082] In the preparation method provided in the embodiment of the present invention, if the display substrate to be manufactured is a color filter substrate of an ADS / IPS type liquid crystal display panel, before step S701, the following steps are further included: forming a shielding layer on the second side surface of the base substrate to shield the interference of the external electric field on the liquid crystal, and the material of the shielding layer can be ITO, such as Figure 5 shown.

[0083] Obviously, those skilled in the art can make various changes and modifications to the embodiments of the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A display substrate, characterized in that: include: A substrate having a first side surface and a second side surface opposite to each other; A black matrix, wherein the black matrix is ​​located on the first side of the base substrate, the black matrix has a plurality of openings, the black matrix comprises a first light-shielding layer and a second light-shielding layer sequentially stacked along a first direction, the material of the first light-shielding layer is a metal material, the material of the second light-shielding layer is a metal semiconductor oxide material, and the first direction is the direction in which the second side points to the first side.

2. The display substrate according to claim 1, characterized in that: The first light shielding layer includes at least two metal layers stacked in sequence along a first direction.

3. The display substrate according to claim 2, characterized in that: The first light-shielding layer includes a first supporting metal layer, an intermediate metal layer, and a second supporting metal layer stacked in sequence along a first direction. The first supporting metal layer and the second supporting metal layer have stronger corrosion resistance than the intermediate metal layer, and the hardness of the first supporting metal layer and the second supporting metal layer is greater than the hardness of the intermediate metal layer.

4. The display substrate according to claim 3, characterized in that: The materials of the first supporting metal layer and the second supporting metal layer are titanium, and the material of the intermediate metal layer is aluminum.

5. The display substrate according to claim 4, characterized in that: The thickness of the first supporting metal layer and the second supporting metal layer along the first direction is 50 angstroms to 1000 angstroms, and the thickness of the intermediate metal layer along the first direction is 500 angstroms to 8000 angstroms.

6. The display substrate according to claim 1, characterized in that: The second light shielding layer includes at least two film layers sequentially arranged along the first direction.

7. The display substrate according to claim 1, characterized in that: The material of the second light shielding layer is at least one of indium tin oxide, indium zinc oxide and indium gallium zinc oxide.

8. The display substrate according to claim 7, characterized in that: The thickness of the second light shielding layer along the first direction is 500 angstroms to 3000 angstroms.

9. The display substrate according to claim 1, characterized in that: It also includes a filter layer located on a side of the black matrix away from the base substrate and a passivation layer located on a side of the filter layer away from the base substrate.

10. The display substrate according to claim 9, characterized in that: It also includes an electrode layer located on a side of the passivation layer away from the substrate.

11. The display substrate according to any one of claims 1 to 9, characterized in that: It also includes a shielding layer located on the second side of the substrate, and the shielding layer is used to shield interference from external electric fields.

12. A display device, characterized in that: Comprising the display substrate as described in any one of claims 1-11.

13. A method for preparing a display substrate, characterized in that: include: Forming a first light shielding layer on the first side surface of the base substrate, wherein the material of the first light shielding layer is a metal material; A second light shielding layer is formed on a side of the first light shielding layer away from the base substrate. The material of the second light shielding layer is a metal semiconductor oxide. The second light shielding layer and the first light shielding layer together form a black matrix. The black matrix has a plurality of openings.

14. The method for preparing a display substrate according to claim 13, characterized in that: After forming the first light shielding layer on the first side of the substrate, the method comprises: patterning the first light shielding layer by a dry etching process; After forming the second light shielding layer on the side of the first light shielding layer away from the base substrate, the method comprises: The second light shielding layer is patterned by a wet etching process.

15. The method for preparing a display substrate according to claim 13, characterized in that: After forming the second light shielding layer on the side of the first light shielding layer away from the base substrate, the method comprises: The first light shielding layer and the second light shielding layer are patterned by a dry etching process.

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