Method for preparing antireflection film, antireflection film, imprinting template and display panel

Abstract

The application provides a preparation method of an antireflection film, the antireflection film, an imprinting template, a display panel and a display device, and relates to the technical field of display. The application solves the problems of complex preparation process, difficult control, low yield and high cost of the antireflection film. The method comprises the following steps: depositing an amorphous silicon layer on a first substrate; performing laser annealing on the amorphous silicon layer to obtain a polycrystalline silicon layer, wherein the polycrystalline silicon layer comprises grain boundary protrusions, and the grain boundary protrusions define a plurality of recesses which are independent of each other; obtaining an imprinting film and performing imprinting on the imprinting film by using the polycrystalline silicon layer to obtain the antireflection film, wherein the antireflection film comprises a plurality of first protrusions, and the plurality of first protrusions and the plurality of recesses correspond to each other. The method obtains the polycrystalline silicon layer by laser annealing, which is conducive to improving the uniformity of the grain boundary protrusions in the polycrystalline silicon layer, and further improves the uniformity of the first protrusions in the antireflection film, thereby improving the uniformity of the contrast ratio of the display panel, and achieving the purpose of controllable, efficient and low-cost preparation of the antireflection film with high yield.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of display, in particular to a preparation method of an antireflection film, the antireflection film, a stamping template, a display panel and a display device. BACKGROUND

[0002] The moth-eye surface is composed of an ordered array of micro-nano structures with a scale smaller than the wavelength of visible light. The structure can be equivalent to a graded refractive index film layer with a continuous gradient of refractive index along the depth direction, which can reduce the reflection phenomenon caused by the large change of refractive index and has a very low reflection coefficient for light. Due to the reflection of the display panel surface of the electronic product in outdoor or strong light environment, the contrast of the display panel is low, and the display panel appears white and glare. The current bionic moth-eye antireflection film can achieve very low reflectivity, and is arranged on the light-emitting side of the display panel, thereby improving the contrast of the display panel. Therefore, it has a wide and important application in the fields of display devices and optical elements.

[0003] At present, the moth-eye antireflection film is usually obtained by self-assembly technology and dry etching process or silver mirror reaction method. However, there are problems of complex preparation process, difficult to control, high cost, and low yield. Therefore, a new preparation method is needed to controllably, efficiently and low-costly prepare a moth-eye antireflection film with high yield. SUMMARY

[0004] In order to solve the above technical problems, the present application is proposed. The embodiments of the present application provide a preparation method of an antireflection film, the antireflection film, a stamping template, a display panel and a display device.

[0005] In a first aspect, an embodiment of the present application provides a preparation method of an antireflection film, the preparation method comprising: depositing an amorphous silicon layer on a first substrate; performing laser annealing on the amorphous silicon layer to obtain a polycrystalline silicon layer, the polycrystalline silicon layer comprising a crystal boundary protrusion, the crystal boundary protrusion defining a plurality of recesses independent of each other; obtaining a stamping film, and stamping the stamping film by using the polycrystalline silicon layer to obtain the antireflection film, wherein the antireflection film comprises a plurality of first protrusions, and the plurality of first protrusions and the plurality of recesses correspond one by one.

[0006] In combination with the first aspect, in some implementations of the first aspect, performing laser annealing on the amorphous silicon layer to obtain the polycrystalline silicon layer comprises: irradiating the amorphous silicon layer by using a laser, and moving on the amorphous silicon layer to obtain a molten amorphous silicon layer; and performing annealing on the molten amorphous silicon layer to recrystallize the molten amorphous silicon layer to obtain the polycrystalline silicon layer.

[0007] With reference to the first aspect, in some implementations of the first aspect, before the amorphous silicon layer is irradiated by the laser, the method further includes: setting the laser beam intensity of the laser to 100 mJ / cm2 to 400 mJ / cm2; setting the laser beam thickness of the laser to 0.3 mm to 0.5 mm; and setting the moving speed of the laser to 4 mm / s to 8 mm / s.

[0008] With reference to the first aspect, in some implementations of the first aspect, the density of the plurality of first protrusions is 8000 per 100 square microns to 10000 per 100 square microns.

[0009] With reference to the first aspect, in some implementations of the first aspect, the height of the first protrusion is greater than or equal to 0.1 microns and less than or equal to 10 microns.

[0010] With reference to the first aspect, in some implementations of the first aspect, the material of the embossed film includes polymethyl acrylate methyl ester.

[0011] In a second aspect, an embodiment of the present application provides an antireflection film prepared by the method for preparing an antireflection film according to any of the above embodiments.

[0012] In a third aspect, an embodiment of the present application provides an embossing template, which includes: a first substrate; a polycrystalline silicon layer located on one side of the first substrate, the polycrystalline silicon layer including grain boundary protrusions, the grain boundary protrusions defining a plurality of recesses independent of each other.

[0013] In a fourth aspect, an embodiment of the present application provides a display panel, which includes: a second substrate; a light emitting device layer located on a surface of one side of the second substrate; and an antireflection film according to any of the above embodiments located on a side of the light emitting device layer away from the second substrate.

[0014] In a fifth aspect, an embodiment of the present application provides a display device, which includes a display panel according to any of the above embodiments.

[0015] The preparation method of the anti-reflection film provided in the embodiments of the present application comprises: depositing an amorphous silicon layer on a first substrate; performing laser annealing on the amorphous silicon layer to obtain a polycrystalline silicon layer, the polycrystalline silicon layer comprising a grain boundary protrusion, the grain boundary protrusion defining a plurality of recesses independent of each other; obtaining an imprint film, and imprinting the imprint film by using the polycrystalline silicon layer to obtain the anti-reflection film, wherein the anti-reflection film comprises a plurality of first protrusions, the plurality of first protrusions and the plurality of recesses corresponding to each other, so that the external light is reflected multiple times between the outer walls of adjacent first protrusions, the energy of the external light is consumed, the energy of the external light emitted from the anti-reflection film is reduced, thereby realizing the low emission rate of the anti-reflection film to the external light, improving the contrast of the display panel, and improving the visual experience effect of the user. Moreover, the preparation method provided in the present application is convenient to control the uniformity of the laser irradiation energy, thereby improving the uniformity of the grain boundary protrusion in the polycrystalline silicon layer, and further improving the uniformity of the first protrusion in the anti-reflection film, thereby improving the uniformity of the contrast of the display panel. Furthermore, the method realizes the controllable, efficient and low-cost preparation of the anti-reflection film with high yield by controlling the laser irradiation energy. BRIEF DESCRIPTION OF DRAWINGS

[0016] The above and other objects, features and advantages of the present application will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which:

[0017] Figure 1 Fig. 1 shows a top view structural schematic diagram of an imprint template provided in an embodiment of the present application.

[0018] Figure 2 Fig. 2 shows a sectional view of the N-N direction of the schematic diagram. Figure 1 Fig. 3 shows a sectional view of the N-N direction of the schematic diagram.

[0019] Figure 3 Fig. 4 shows a structural schematic diagram of an imprint template and an imprint film provided in an embodiment of the present application.

[0020] Figure 4 Fig. 5 shows a top view structural schematic diagram of an anti-reflection film provided in an embodiment of the present application.

[0021] Figure 5 Fig. 6 shows a sectional view of the N-N direction of the schematic diagram. Figure 4 Fig. 7 shows a sectional view of the N-N direction of the schematic diagram.

[0022] Figure 6 Fig. 8 shows a structural schematic diagram of a display panel provided in an embodiment of the present application.

[0023] Figure 7 Fig. 9 shows a flow schematic diagram of a preparation method of an anti-reflection film provided in an embodiment of the present application.

[0024] Figure 8 Fig. 2 shows a flowchart of a method for preparing an antireflection film according to another embodiment of the present application.

[0025] Figure 9 Fig. 3 shows a schematic diagram of a structure for irradiating an amorphous silicon layer by a laser according to an embodiment of the present application.

[0026] Figure 10 Fig. 2 shows a flowchart of a method for preparing an antireflection film according to another embodiment of the present application.

[0027] Figure 11 Fig. 4 shows a schematic diagram of a structure of a display device according to an embodiment of the present application.

[0028] Fig. 4 shows a schematic diagram of a structure of a display device according to an embodiment of the present application. Fig. 4 shows a schematic diagram of a structure of a display device according to an embodiment of the present application. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application will be apparently and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0030] In addition, in order to better illustrate the present application, numerous specific details are given in the following detailed description. A person of ordinary skill in the art should understand that the present application can be implemented without some specific details. In some examples, methods and means familiar to a person of ordinary skill in the art are not described in detail, in order to highlight the main ideas of the present application.

[0031] It should be noted that: similar reference numerals and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0032] In addition, if the terms "first", "second", etc. are used, they are only used for distinguishing description, and cannot be understood as indicating or implying relative importance.

[0033] Figure 1 Fig. 1 shows a top view of a structure of an imprinting template according to an embodiment of the present application. Figure 2 Fig. 2 shows a flowchart of a method for preparing an antireflection film according to another embodiment of the present application. Figure 1The N-N direction cross-sectional view of the schematic diagram is shown. In combination Figure 1 and Figure 2 As shown, the embossing template 100 provided by the embodiments of the present application includes: a first substrate 110; a polysilicon layer 120 located on one side of the first substrate 110, the polysilicon layer 120 includes grain boundary protrusions 1211, and the grain boundary protrusions 1211 define a plurality of grooves 1212 independent of each other.

[0034] The grain boundary protrusions 1211 and the grooves 1212 defined by the grain boundary protrusions 1211 constitute a grain 121. Specifically, the boundary of the grain 121 generates the grain boundary protrusions 1211 due to extrusion. As shown, Figure 1 The plurality of grains 121 are irregularly arranged and closely adjacent.

[0035] In some embodiments, the first substrate 110 can be a glass substrate. In addition, a buffer layer can be arranged between the first substrate 110 and the polysilicon layer 120 to reduce the influence of the irradiation energy of the laser on the first substrate 110 when the amorphous silicon layer is irradiated, for example, to prevent the first substrate 110 from cracking due to excessive irradiation energy of the laser. The material of the buffer layer can be SiN.

[0036] In some embodiments, the polysilicon layer 120 can be located on the surface of the first substrate 110.

[0037] As shown, Figure 1 As shown, Figure 1 The lines in the figure represent the grain boundary protrusions 1211, and the plurality of independent regions surrounded by the lines represent the grooves 1212. The shape of the orthographic projection of the grain boundary protrusions 1211 on the first substrate 110 is random. It should be noted that, Figure 1 The embossing template 100 is obtained by electron microscopy.

[0038] The grain boundary protrusions 1211 of the embossing template 100 provided by the embodiments of the present application are relatively uniform, avoiding the phenomenon that the grain boundary protrusions 1211 in one part of the polysilicon layer 120 are dense and the grain boundary protrusions 1211 in another part are sparse, thereby improving the yield of the antireflection film obtained by subsequent embossing. The embossing template 100 provided by the embodiments of the present application has low economic cost, simple preparation process, and can realize industrial large-area preparation, so the preparation efficiency is high.

[0039] Figure 3 As shown, the embossing template and the structure of the embossing film provided by an embodiment of the present application are shown. As shown, Figure 3 The embossing film 200 is located on the side close to the grain boundary protrusions 1211 of the embossing template 100.

[0040] In some embodiments, the material of the embossing film 200 includes polymethyl acrylate methyl ester. It is easy to obtain and has low cost.

[0041] Figure 4 Fig. 1 shows a top view of a structure of an antireflection film according to an embodiment of the present application. Figure 5 Fig. 2 shows a schematic diagram of a cross section of the antireflection film along the direction N-N in Fig. 1. Figure 4 Fig. 3 shows a schematic diagram of a cross section of the antireflection film along the direction N-N in Fig. 1. Figure 4 Fig. 4 shows a schematic diagram of a cross section of the antireflection film along the direction N-N in Fig. 1. Figure 5 Fig. 5 shows a top view of a structure of an antireflection film according to an embodiment of the present application. Fig. 6 shows a top view of a structure of an antireflection film according to an embodiment of the present application.

[0042] Fig. 7 shows a top view of a structure of an antireflection film according to an embodiment of the present application. Figure 4 Fig. 8 shows a top view of a structure of an antireflection film according to an embodiment of the present application.

[0043] In some embodiments, the density of the first protrusions A1 is 8000 per 100 square microns to 10000 per 100 square microns. The first protrusions A1 with the above density not only achieve low light extraction of the antireflection film A to the external light G, but also are relatively easy to be prepared by the process. Of course, since the first protrusions A1 are obtained by imprinting the grain boundary protrusions 1211 of the polysilicon layer 120, the density of the grain boundary protrusions 1211 is equal to the density of the first protrusions A1, i.e., the density of the grain boundary protrusions 1211 is also 8000 per 100 square microns to 10000 per 100 square microns.

[0044] In some embodiments, the height of the first protrusions A1 is greater than or equal to 0.1 microns and less than or equal to 10 microns. The first protrusions A1 with the above height range not only make the external light G reflect multiple times between the outer walls of adjacent first protrusions A1, consume the energy of the external light G, and reduce the energy of the external light G extracted from the antireflection film A, but also are relatively easy to be prepared by the process. Of course, since the first protrusions A1 are one-to-one corresponding to the grooves 1212, the grooves 1212 are obtained by the grain boundary protrusions 1211, the height of the first protrusions A1 is equal to the depth of the grooves 1212, and also equal to the height of the grain boundary protrusions 1211, i.e., the height of the grain boundary protrusions 1211 is greater than or equal to 0.1 microns and less than or equal to 10 microns.

[0045] The antireflection film A provided by the embodiments of the present application includes a plurality of first protrusions A1 of micro-nano order, which is similar to the micro-nano structure array of the moth eye surface and has the same advantage of low light extraction to the external light G. By arranging the antireflection film A on the light-emitting side of the display panel, the contrast of the display panel is improved, and the white emission and glare phenomenon are improved. In addition, the first protrusions A1 of the antireflection film A provided by the embodiments of the present application are relatively uniform, thereby improving the uniformity of the contrast of the display panel and further optimizing the display effect.

[0046] Figure 6The diagram shown is a structural schematic of a display panel provided in one embodiment of this application. Figure 6 As shown, the display panel 310 provided in this application embodiment includes: a second substrate 311; a light-emitting device layer 312 located on one side of the second substrate 311; and an anti-reflection film A as mentioned in the above embodiment, located on the side of the light-emitting device layer 312 facing away from the second substrate 311.

[0047] It should be noted that the external light G refers to light other than the light emitted from the light-emitting device layer 312 of the display panel 310, that is, light emitted from a light source other than the light-emitting device layer 312.

[0048] The display panel 310 provided in this embodiment has a low emissivity to external light G, so that the vast majority of the light entering the user's eye is emitted from the light-emitting device layer 312 of the display panel 310, while the proportion of light emitted from the external light G through the anti-reflection film A is extremely small, or even zero. Therefore, the display panel 310 provided in this embodiment reduces the interference of external light G on the light emitted from the light-emitting device layer 312, thereby improving the contrast of the display panel 310 and enhancing the user's visual experience.

[0049] The preparation method of the antireflective film A provided in the embodiments of this application will be described in detail below. Before that, the principle of generating the grain boundary protrusions 1211 will be explained.

[0050] When recrystallizing an amorphous silicon layer using laser annealing, the amorphous silicon layer is completely melted by a high-energy laser. The molten amorphous silicon layer is then recrystallized. During the recrystallization process, grain boundary protrusions 1211 are generated at the grain boundaries of the grains 121 due to compression.

[0051] Figure 7 The diagram shown is a schematic flow chart of a method for preparing an antireflective film according to an embodiment of this application. Figure 7 As shown, the method for preparing the antireflective film provided in this application includes:

[0052] Step S701: Deposit an amorphous silicon layer on the first substrate 110;

[0053] Step S702: Laser annealing is performed on the amorphous silicon layer to obtain a polycrystalline silicon layer 120;

[0054] See Figure 2 The polycrystalline silicon layer 120 includes grain boundary protrusions 1211, which define a plurality of independent grooves 1212.

[0055] In some embodiments, the amorphous silicon layer is irradiated with an excimer laser, which provides higher irradiation precision and energy.

[0056] In step S703, the imprinting film 200 is obtained, and the imprinting film 200 is imprinted by using the polysilicon layer 120 to obtain the anti-reflection film A.

[0057] Referring to Figure 3 , the imprinting film 200 is located on the side close to the grain boundary protrusion 1211.

[0058] In some embodiments, pressure is applied to the polysilicon layer 120 and the imprinting film 200 to deform the surface of the imprinting film 200 to form a plurality of first protrusions A1 corresponding to the plurality of grooves 1212.

[0059] The anti-reflection film A prepared by the embodiment of the present application comprises a plurality of first protrusions A1, and the plurality of first protrusions A1 and the plurality of grooves 1212 correspond one-to-one, so that the external light G is reflected multiple times between the outer walls of adjacent first protrusions A1, consumes the energy of the external light G, and reduces the energy of the external light G emitted from the anti-reflection film A, thereby realizing the low emission rate of the anti-reflection film A to the external light G, thereby improving the contrast of the display panel 310 and improving the visual experience effect of the user. It should be emphasized that the preparation method provided by the embodiment of the present application utilizes the uniformity of the laser irradiation energy, thereby improving the uniformity of the grain boundary protrusion 1211 in the polysilicon layer 120, and further improving the uniformity of the first protrusion A1 in the anti-reflection film A, thereby improving the uniformity of the contrast of the display panel 310. Moreover, the preparation method provided by the embodiment of the present application has simple process, can realize industrial large-area preparation, and has high preparation efficiency; furthermore, the optional material of the imprinting film 200 is relatively extensive, and the cost is relatively low.

[0060] Figure 8 Fig. 4 shows a flowchart of a preparation method of an anti-reflection film provided by another embodiment of the present application. Figure 9 Fig. 2 shows a structure diagram of the laser irradiating the amorphous silicon layer provided by an embodiment of the present application. In combination with Figure 8 and Figure 9 As shown in the figure, the laser annealing is performed on the amorphous silicon layer F to obtain the polysilicon layer 120, which comprises:

[0061] In step S801, the laser Q irradiates the amorphous silicon layer F, and moves on the amorphous silicon layer F to obtain the molten amorphous silicon layer F.

[0062] As Figure 9 shown, the laser beam S emitted by the laser Q irradiates the amorphous silicon layer F and the laser Q irradiates the amorphous silicon layer F by moving, so that the amorphous silicon layer F is molten by the high-energy laser emitted by the laser Q. Wherein, the direction Y of the laser movement is the direction pointing to the amorphous silicon layer F.

[0063] In this step, the irradiation direction of the laser beam S can be perpendicular to the plane where the amorphous silicon layer F is located, which is conducive to improving the accuracy of the laser beam S aiming at the silicon atom, and the operation is more convenient.

[0064] At step S802, the molten amorphous silicon layer F is annealed to recrystallize the molten amorphous silicon layer F to obtain a polycrystalline silicon layer 120.

[0065] As shown in FIG. 12, after the molten amorphous silicon layer F is annealed, the molten amorphous silicon layer F is recrystallized to obtain a polycrystalline silicon layer 120, which is composed of regular chessboard-shaped particles. Figure 9 In some embodiments, the laser Q can be an excimer laser, and the laser annealing process is referred to as an excimer laser annealing process.

[0066]

[0067] As shown in FIG. 13, the preparation method of the anti-reflective film provided in another embodiment of the present application includes the following steps. Figure 10 As shown in FIG. 13, before the amorphous silicon layer F is irradiated by the laser Q, the following steps are further included: Figure 10 At step S1001, the intensity of the laser beam S of the laser Q is set to 100-400 mJ / cm2;

[0068] At step S1002, the thickness of the laser beam S of the laser Q is set to 0.3-0.5 mm;

[0069] At step S1003, the moving speed of the laser Q is set to 4-8 mm / s.

[0070] In steps S1001-S1003, the intensity, thickness and moving speed of the laser beam S of the laser Q are controlled according to the height and density of the grain boundary protrusions 1211 obtained in practice. The thickness of the laser beam S refers to the length of the laser beam S irradiated on the same silicon atom from the beginning to the end of the irradiation, and the thickness of the laser beam S and the moving speed of the laser Q together determine the irradiation time of the same silicon atom.

[0071] Specifically, the greater the intensity of the laser beam S and the greater the thickness of the laser beam S and the smaller the moving speed of the laser Q, the greater the laser energy received by the amorphous silicon layer F, and thus the more sufficient the melting of the amorphous silicon layer F, and the higher and sparser the grain boundary protrusions 1211 generated in the annealing process. On the contrary, the smaller the intensity of the laser beam S and the smaller the thickness of the laser beam S and the greater the moving speed of the laser Q, the smaller the laser energy received by the amorphous silicon layer F, and thus the less sufficient the melting of the amorphous silicon layer F, and the lower and denser the grain boundary protrusions 1211 generated in the annealing process.

[0072]

[0073] ​Therefore, the preparation method provided in this application embodiment, by flexibly setting the intensity, thickness, and speed of the laser beam S in the above steps, generates grain boundary protrusions 1211 of various heights and densities, thereby obtaining first protrusions A1 of various heights and densities, that is, obtaining a variety of antireflection films A, thus having a low emissivity for external light G of various wavelengths, and improving the controllability of the preparation process.

[0074] Figure 11 The diagram shown is a structural schematic of a display device provided in an embodiment of this application. Figure 11 As shown, one embodiment of this application also provides a display device 300. It is understood that the display panel 310 can be applied to the display device 300, which can be, for example, any product or component with display functionality such as a mobile terminal, tablet computer, computer monitor, television, wearable device, or information kiosks. The display device 300 includes the display panel 310 as in any embodiment of this application, and its technical principles and effects are similar, so they will not be described again here.

[0075] The basic principles of this application have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of each embodiment of this application. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the application to the necessity of employing the aforementioned specific details for implementation.

[0076] The block diagrams of devices, apparatuses, devices, and systems involved in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

[0077] It should also be noted that in the apparatus, equipment, and methods of this application, the components or steps can be disassembled and / or recombined. These disassemblies and / or recombinations should be considered as equivalent solutions of this application.

[0078] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other aspects without departing from the scope of the application. Thus, the present application is not intended to be limited to the aspects shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0079] The above description has been presented to enable any person skilled in the art to make or use the application. Numerous modifications and alterations to this application will be readily apparent to those skilled in the art, and it is intended to include all such modifications and alterations insofar as they come within the scope of the general concepts defined herein.

Claims

1. A method for preparing an antireflective film, characterized in that, include: An amorphous silicon layer is deposited on the first substrate; The amorphous silicon layer is laser annealed to obtain a polycrystalline silicon layer, the polycrystalline silicon layer including grain boundary protrusions, the grain boundary protrusions defining a plurality of independent grooves; An imprint film is obtained, and the imprint film is imprinted using the polycrystalline silicon layer to obtain the antireflective film, wherein the antireflective film includes a plurality of first protrusions, and the plurality of first protrusions and the plurality of grooves correspond one-to-one; The density of the plurality of first protrusions is from 8,000 per 100 square micrometers to 10,000 per 100 square micrometers; The method further includes: providing a buffer layer between the first substrate and the polysilicon layer.

2. The preparation method according to claim 1, characterized in that, The process of laser annealing the amorphous silicon layer to obtain a polycrystalline silicon layer includes: The amorphous silicon layer is irradiated with a laser and moved on the amorphous silicon layer to obtain a molten amorphous silicon layer; The molten amorphous silicon layer is annealed to recrystallize the molten amorphous silicon layer, thereby obtaining the polycrystalline silicon layer.

3. The preparation method according to claim 2, characterized in that, Before irradiating the amorphous silicon layer with a laser, the method further includes: The laser beam intensity of the laser is set to be between 100 millijoules per square centimeter and 400 millijoules per square centimeter; The laser beam thickness of the laser is set to 0.3 mm to 0.5 mm; The laser's moving speed is set to 4 mm / s to 8 mm / s.

4. The preparation method according to claim 1, characterized in that, The height of the first protrusion is greater than or equal to 0.1 micrometers and less than or equal to 10 micrometers.

5. The preparation method according to any one of claims 1 to 4, characterized in that, The material of the embossed film includes polymethyl methacrylate.

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