Blackbody and its preparation method and application

Abstract

The present application belongs to the field of black body technology, and provides a black body and a preparation method and application thereof, wherein the black body comprises a crystal substrate, the surface of the crystal substrate has a plurality of inverted pyramid grooves, and the surface of the inverted pyramid grooves has a microstructure. The present application uses a crystal material as a substrate, and forms an inverted pyramid groove with a microstructure on the surface of the crystal material, which not only has a good wave absorption effect and good stability, but also is easy to process and prepare.

Description

Technical Field

[0001] The present application relates to the technical field of black bodies, and in particular to a black body and a preparation method and application thereof. Background Art

[0002] At present, black bodies include coated black bodies and structured black bodies. Among them, the coated black body forms a coating structure on the surface of the substrate, and uses the membrane structure and the coating structure to achieve the wave absorbing function. However, the bonding force between the coating structure and the substrate in the coated black body is poor, which easily causes the coating structure to fall off. The structured black body refers to a micron-level quasi-periodic array structure black body, which uses the wave absorbing structure on the surface of the substrate to achieve the wave absorbing function. Copper or silver is usually selected as the substrate, and then the wave absorbing structure is formed on the surface of the substrate. However, the wave absorbing efficiency of the structured black body is difficult to guarantee and difficult to process. Therefore, how to provide a black body with high wave absorbing efficiency, good stability and easy processing and preparation has become a technical problem that urgently needs to be solved. Summary of the invention

[0003] Based on this, an embodiment of the present application provides a black body with high wave absorption efficiency, good stability and easy processing and preparation, and a preparation method and application thereof.

[0004] In a first aspect, the present application provides a black body, which includes a crystal substrate, a surface of the crystal substrate having a plurality of inverted pyramid grooves, and a surface of the inverted pyramid grooves having a microstructure.

[0005] In some embodiments, a plurality of the inverted pyramid grooves are arranged in an array on the surface of the crystal substrate.

[0006] In some embodiments, the depth of the inverted pyramid groove is 15 μm to 40 μm; and the spacing distance between adjacent inverted pyramid grooves is 20 μm to 40 μm.

[0007] In some embodiments, the microstructure comprises a particulate structure.

[0008] In some embodiments, the average diameter of the particle structure is 300 nm to 400 nm.

[0009] In some embodiments, the material of the crystalline substrate includes at least one of silicon, germanium, silicon carbide, and diamond.

[0010] In some embodiments, at least a portion of the surface of the inverted pyramid groove includes a modified material layer.

[0011] In some embodiments, the material of the modified material layer includes at least one of an oxide and a hydrate.

[0012] In a second aspect, the present application provides a method for preparing a black body, the method for preparing a black body comprising:

[0013] providing a crystalline substrate;

[0014] forming a plurality of prefabricated holes on the surface of the crystal substrate;

[0015] Using an etchant to etch the crystal substrate having the plurality of preformed holes, so as to anisotropically etch the preformed holes to form inverted pyramid grooves;

[0016] The crystal substrate after the etching process is subjected to laser irradiation process, so that a microstructure is formed on the surface of the inverted pyramid groove.

[0017] In some embodiments, the plurality of prefabricated holes are arranged in an array on the crystalline substrate.

[0018] In some embodiments, the preformed holes have an average diameter of 10 μm to 20 μm and a depth of 10 μm to 30 μm.

[0019] In some embodiments, the spacing distance between adjacent preformed holes is 20 μm to 40 μm.

[0020] In some embodiments, the etchant includes at least one of an acid solution, an alkaline solution, a salt solution, and an organic solvent.

[0021] In some embodiments, the laser irradiation treatment uses a laser with a pulse width of 1 fs to 100 ps and a power of 0.5 W to 2 W.

[0022] In some embodiments, the method of forming a plurality of pre-made holes on the surface of the crystalline substrate comprises laser drilling.

[0023] In some embodiments, the laser opening uses a laser with a pulse width of 1 fs to 100 ps and a power of 2 W to 5 W.

[0024] In a third aspect, the present application provides an application of a black body as described in the first aspect or a black body prepared by the method for preparing a black body as described in the second aspect in preparing a thermal imaging device.

[0025] Compared with the traditional technology, this application has at least the following beneficial effects:

[0026] The present application uses a crystal material as the substrate of the black body, and forms a microstructured inverted pyramid groove wave-absorbing structure on the surface of the crystal material, which cooperates to achieve a high wave-absorbing effect and has the stability of a structural black body. In addition, compared with metal materials such as copper, the crystal material is easier to process over a large area to form a wave-absorbing structure. Therefore, the black body of the present application has the characteristics of high stability, good wave-absorbing effect, and easy processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a scanning electron microscope image of the crystal substrate after laser drilling in Example 1 of the present application.

[0028] Figure 2 This is a scanning electron microscope image of the crystal substrate after etching treatment in Example 1 of the present application.

[0029] Figure 3 This is another scanning electron microscope image of the crystal substrate after etching treatment in Example 1 of the present application.

[0030] Figure 4 This is a scanning electron microscope image of the crystal substrate after laser irradiation treatment in Example 1 of the present application.

[0031] Figure 5 This is another scanning electron microscope image of the crystal substrate after laser irradiation treatment in Example 1 of the present application. DETAILED DESCRIPTION

[0032] Below in conjunction with the embodiments and examples, the present application is further described in detail. These embodiments and examples are only used to illustrate the present application and are not used to limit the scope of the present application. The purpose of providing these embodiments and examples is to make the understanding of the disclosure of the present application more thorough and comprehensive. It should also be understood that the present application can be implemented in many different forms, and is not limited to the embodiments and examples described herein. Those skilled in the art can make various changes or modifications without violating the connotation of the present application, and the equivalent form obtained also falls within the protection scope of the present application. In addition, in the description below, a large number of specific details are given in order to provide a more comprehensive understanding of the present application. It should be understood that the present application can be implemented without one or more of these details.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0034] In this application, "optionally", "optional", and "optional" mean optional or dispensable, that is, any one of the two parallel schemes of "yes" or "no". If multiple "options" appear in a technical solution, unless otherwise specified and there is no contradiction or mutual restriction, each "optional" is independent.

[0035] In this application, the terms "first", "second", etc. in "the first aspect", "the second aspect", etc. are used only for descriptive purposes and cannot be understood as indicating or implying relative importance or quantity, nor can they be understood as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first", "second", etc. only serve the purpose of non-exhaustive enumeration and description, and it should be understood that they do not constitute a closed limitation on quantity.

[0036] In the present application, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0037] In the present application, when it comes to a numerical interval (i.e., a numerical range), unless otherwise specified, the distribution of the optional numerical values ​​in the numerical interval is considered to be continuous, and includes the two numerical endpoints (i.e., the minimum and maximum values) of the numerical interval, and each numerical value between the two numerical endpoints. Unless otherwise specified, when the numerical interval only refers to an integer in the numerical interval, it includes the two endpoint integers of the numerical range, and each integer between the two endpoints, which is equivalent to directly listing each integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be combined. In other words, unless otherwise specified, the numerical range disclosed in the present application should be understood to include any and all sub-ranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, a percentage, a ratio, etc. "Numerical interval" allows for a broad range of quantitative intervals such as percentage intervals, ratio intervals, and ratio intervals.

[0038] All documents mentioned in this application are cited as references in this application, just as each document is cited as reference separately. Unless they conflict with the application purpose and / or technical solution of this application, the cited documents involved in this application are cited with all contents and all purposes. When the cited documents are involved in this application, the definitions of relevant technical features, terms, nouns, phrases, etc. in the cited documents are also cited. When the cited documents are involved in this application, the examples and preferred methods of the cited relevant technical features can also be incorporated into this application as references, but are limited to the implementation of this application. It should be understood that when the cited content conflicts with the description in this application, the present application shall prevail or be modified adaptively according to the description of this application.

[0039] In traditional technology, coated black bodies have poor stability due to the problem of easy detachment between the coating and the substrate. Structured black bodies are usually made of copper or silver metal materials. Although the stability of the black body is good, the absorbing structure is difficult to process and the absorbing effect is difficult to improve. The present application found that using crystalline materials as the substrate of the black body has better processing performance than metal materials, and microstructures can be formed in situ on the crystalline material, which can synergistically improve the absorbing effect of the black body.

[0040] In a first aspect, the present application provides a black body, which includes a crystal substrate, a surface of the crystal substrate having a plurality of inverted pyramid grooves, and a surface of the inverted pyramid grooves having a microstructure.

[0041] The present application uses a crystal material as the substrate of the black body, and forms a microstructured inverted pyramid groove wave-absorbing structure on the surface of the crystal material, which cooperates to achieve a high wave-absorbing effect and has the stability of a structural black body. In addition, compared with metal materials such as copper, the crystal material is easier to process over a large area to form a wave-absorbing structure. Therefore, the black body of the present application has the characteristics of high stability, good wave-absorbing effect, and easy processing.

[0042] In some embodiments, a plurality of the inverted pyramid grooves are arranged in an array on the surface of the crystal substrate.

[0043] It is understandable that the present application does not impose any specific requirements or restrictions on the form of the array arrangement, and it can be reasonably selected according to the wave absorbing effect. Optionally, the plurality of inverted pyramid grooves are arranged in a rectangular array on the surface of the crystal substrate.

[0044] In some embodiments, the depth of the inverted pyramid groove is 15 μm to 40 μm, for example, it can be 15 μm, 16 μm, 18 μm, 20 μm, 22 μm, 24 μm, 26 μm, 28 μm, 30 μm, 32 μm, 34 μm, 36 μm, 38 μm or 40 μm.

[0045] In some embodiments, the spacing distance between adjacent inverted pyramid grooves is 20 μm to 40 μm, for example, 20 μm, 22 μm, 24 μm, 26 μm, 28 μm, 30 μm, 32 μm, 34 μm, 36 μm, 38 μm or 40 μm.

[0046] It is understood that the spacing distance in this application refers to the distance between the centroids of two adjacent structural shapes on the same horizontal plane. Taking the spacing distance between inverted pyramid grooves as an example, it means that on the same plane, the spacing distance refers to the distance between the vertices of the inverted pyramid grooves.

[0047] In some embodiments, the microstructure comprises a particulate structure.

[0048] In some embodiments, the average diameter of the particle structure is 300 nm to 400 nm, for example, 300 nm, 310 nm, 320 nm, 330 nm, 340 nm, 350 nm, 360 nm, 370 nm, 380 nm, 390 nm or 400 nm.

[0049] In some embodiments, the material of the crystalline substrate includes at least one of silicon, germanium, silicon carbide, and diamond.

[0050] In some embodiments, at least a portion of the surface of the inverted pyramid groove includes a modified material layer.

[0051] In some embodiments, the material of the modified material layer includes at least one of an oxide and a hydrate.

[0052] In some embodiments, the modified material layer is formed in situ on the crystal substrate. In the present application, the modified material layer is formed in situ on the crystal substrate, thereby ensuring the stability of the combination of the modified material layer and the crystal substrate. Furthermore, after the surface material of the inverted pyramid groove is modified, the wave absorption effect of the black body can be effectively improved.

[0053] In some embodiments, the material of the crystalline substrate includes silicon, and the material of the modified material layer includes at least one of silicon oxide and silicon hydrate, wherein the modified material layer is in-situ formed on the crystalline substrate.

[0054] A second aspect of the present application provides a method for preparing a black body, the method for preparing a black body comprising:

[0055] providing a crystalline substrate;

[0056] forming a plurality of prefabricated holes on the surface of the crystal substrate;

[0057] Using an etchant to etch the crystal substrate having the plurality of preformed holes, so as to anisotropically etch the preformed holes to form inverted pyramid grooves;

[0058] The crystal substrate after the etching process is subjected to laser irradiation process, so that a microstructure is formed on the surface of the inverted pyramid groove.

[0059] The present application forms a plurality of prefabricated holes on a crystal substrate in advance, and then performs anisotropic etching with an etchant, so that the prefabricated holes are etched into inverted pyramid grooves under the action of anisotropic etching, thereby forming a wave-absorbing structure of a black body; in addition, by subjecting the inverted pyramid grooves formed by etching to laser irradiation treatment, the crystal material undergoes material modification and laser etching, thereby forming a modified material layer and a microstructure in situ on the surface of the inverted pyramid groove, thereby improving the wave-absorbing effect of the black body. The present application realizes large-area preparation of black bodies by means of opening holes, etching, and laser irradiation, and the preparation process is simple, the preparation efficiency is high, and the cost is low.

[0060] It is understandable that the present application does not make any specific requirements or special limitations on the shape of the prefabricated hole, and it can be reasonably selected according to the shape of the inverted pyramid groove. For example, the prefabricated hole can be a columnar hole, such as a cylindrical or square column; it can also be a conical hole, such as a conical hole.

[0061] In some embodiments, the thickness of the crystalline substrate is 0.5 mm to 3 mm, for example, 0.5 mm, 0.6 mm, 0.9 mm, 1.2 mm, 1.5 mm, 1.8 mm, 2.1 mm, 2.4 mm, 2.7 mm or 3.0 mm.

[0062] In some embodiments, a plurality of the prefabricated holes are arranged in an array on the crystalline substrate.

[0063] In some embodiments, the average diameter of the preformed holes is 10 μm to 20 μm, for example, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm or 20 μm.

[0064] In some embodiments, the depth of the prefabricated hole is 10 μm to 30 μm, for example, it can be 10 μm, 12 μm, 14 μm, 16 μm, 18 μm, 20 μm, 22 μm, 24 μm, 26 μm, 28 μm or 30 μm.

[0065] In some embodiments, the spacing distance between adjacent preformed holes is 20 μm to 40 μm, for example, 20 μm, 22 μm, 24 μm, 26 μm, 28 μm, 30 μm, 32 μm, 34 μm, 36 μm, 38 μm or 40 μm.

[0066] In some embodiments, the etchant includes at least one of an acid solution, an alkaline solution, a salt solution, and an organic solvent.

[0067] In some embodiments, the material of the crystalline substrate is silicon, and the etchant includes a potassium hydroxide solution.

[0068] In some embodiments, after the laser irradiation treatment, the surface of the inverted pyramid groove undergoes material modification, and a modified material layer is formed in situ. It is understandable that the modified material layer is generated in situ on the inverted pyramid groove, and there may be a clear interface between the modified material layer and the inverted pyramid groove, or there may be a mixed material transition layer of the modified material layer and the crystalline substrate material between the modified material layer and the inverted pyramid groove.

[0069] In some embodiments, the crystal substrate after the etching process is cleaned and dried before being irradiated with laser.

[0070] In some embodiments, the laser irradiation treatment uses a laser pulse width of 1fs~100ps, for example, it can be 1fs, 10fs, 50fs, 100fs, 200fs, 300fs, 400fs, 500fs, 600fs, 700fs, 800fs, 900fs, 1ps, 10ps, 20ps, 30ps, 40ps, 50ps, 60ps, 70ps, 80ps, 90ps or 100ps.

[0071] In some embodiments, the laser irradiation treatment uses a laser with a power of 0.5 W to 2 W, for example, 0.5 W, 0.6 W, 0.8 W, 1.0 W, 1.2 W, 1.4 W, 1.6 W, 1.8 W or 2.0 W.

[0072] The present application appropriately selects the laser power of the laser irradiation treatment to ensure that the microstructure and modified material are formed on the surface of the inverted pyramid groove, avoiding the occurrence of problems such as insufficient surface microstructure density, uneven thickness of the modified layer, and damage to the inverted pyramid material. If the power is relatively small, it may lead to fewer surface microstructures and shallow depth of the modified layer, which in turn causes the absorption performance of the black body to decrease. If the power is relatively large, it may cause the inverted pyramid structure to be destroyed, and it may also cause uneven modification of the material surface and uneven distribution of the microstructure, resulting in a decrease in absorption performance.

[0073] It is understandable that when the material of the crystal substrate is silicon, intrinsic silicon particles, silicon dioxide and silicon hydrates will be generated under laser irradiation, wherein the intrinsic silicon particles can absorb the 3μm~12μm band, silicon dioxide can absorb the 6μm~10μm band, and silicon hydrates can absorb the 3μm~6μm band. By adjusting the power of laser irradiation, the intrinsic silicon particles, silicon dioxide and silicon hydrates are evenly distributed, and the absorption effect of the black body in the 3μm~12μm band is improved.

[0074] In some embodiments, the laser spot diameter used in the laser irradiation treatment is 50 μm to 200 μm, for example, it can be 50 μm, 60 μm, 80 μm, 100 μm, 120 μm, 140 μm, 160 μm, 180 μm or 200 μm.

[0075] In some embodiments, the method of forming a plurality of prefabricated holes on the surface of the crystalline substrate comprises laser drilling.

[0076] The present application adopts a laser drilling method to form prefabricated holes on a crystal substrate. The laser drilling method can directly process the crystal substrate to form a self-masking film. The process is simple, and the hole diameter and hole depth can be controlled by laser parameters, thereby controlling the depth and width of the inverted cone structure to obtain the best light absorption structure and improve the preparation efficiency of the black body.

[0077] In some embodiments, the pulse width of the laser used for laser opening is 1fs~100ps, for example, it can be 1fs, 10fs, 50fs, 100fs, 200fs, 300fs, 400fs, 500fs, 600fs, 700fs, 800fs, 900fs, 1ps, 10ps, 20ps, 30ps, 40ps, 50ps, 60ps, 70ps, 80ps, 90ps or 100ps.

[0078] In some embodiments, the power of the laser used for laser drilling is 2W~5W, for example, it can be 2.0W, 2.3W, 2.6W, 2.9W, 3.2W, 3.5W, 3.8W, 4.1W, 4.4W, 4.7W or 5.0W.

[0079] Exemplarily, a method for preparing the above-mentioned blackbody is provided, comprising:

[0080] S1. providing a crystal substrate;

[0081] S2, forming a plurality of prefabricated holes arranged in an array on the crystal substrate of step S1 by laser drilling, wherein the laser pulse width used for laser drilling is 1fs~100ps, the power is 2W~5W, and the average diameter of the prefabricated holes is 10μm~20μm, the depth is 10μm~30μm, and the spacing is 20μm~40μm;

[0082] S3, immersing the crystal substrate with the prefabricated holes in step S2 into an etchant for etching, so that the prefabricated holes are anisotropically etched to form inverted pyramid grooves, the depth of the inverted pyramid grooves is 15 μm to 40 μm, and the spacing is 20 μm to 40 μm;

[0083] S4, laser irradiating the crystal substrate after the etching process in step S3 to modify the surface of the inverted pyramid groove so that a microstructure is formed on the surface of the inverted pyramid groove. The laser irradiation uses a laser pulse width of 1fs~100ps and a power of 0.5W~2W to prepare the black body.

[0084] A third aspect of the present application provides an application of a black body as described in the first aspect or a black body prepared by the method for preparing a black body as described in the second aspect in preparing a thermal imaging device.

[0085] The embodiments of the present application will be described in detail below in conjunction with examples. It should be understood that these examples are only used to illustrate the present application and are not intended to limit the scope of the present application. The experimental methods for which specific conditions are not specified in the following examples are preferably referred to the guidance provided in the present application, and can also be based on the experimental manual or normal conditions in this area, can also be based on the conditions recommended by the manufacturer, or refer to experimental methods known in the art.

[0086] Example 1

[0087] S1. Provide a crystalline substrate with a thickness of 0.7 mm and made of silicon;

[0088] S2, such as Figure 1As shown, in step S1, a plurality of cylindrical preformed holes arranged in a matrix are formed on the crystal substrate by laser drilling. The laser drilling uses a laser pulse width of 300 fs and a power of 3 W. The average diameter of the preformed holes is 15 μm, the depth is 20 μm, and the spacing is 30 μm.

[0089] S3, immersing the crystal substrate with prefabricated holes in step S2 into a potassium hydroxide aqueous solution with a mass concentration of 5% for etching for 40 minutes. Figure 2 and Figure 3 As shown, an inverted pyramid groove (inverted pyramid structure) is formed by anisotropic etching at the prefabricated hole, the depth of the inverted pyramid groove is 30 μm, and the spacing distance is 30 μm;

[0090] S4, after cleaning and drying, the crystal substrate after etching in step S3 is subjected to laser irradiation for 20 minutes to modify the surface of the inverted pyramid groove, such as Figure 4 and Figure 5 As shown, a microstructure is formed on the surface of the inverted pyramid groove, and the surface material of the inverted pyramid groove is modified under laser irradiation to form intrinsic silicon particles, silicon oxide and silicon hydrate. The laser irradiation uses a laser pulse width of 300fs and a power of 1W. The microstructure includes a particle structure with an average particle size of 350nm and a groove structure with a width of 30μm and a depth of 30μm, thereby preparing the black body.

[0091] Example 2

[0092] S1. Provide a crystalline substrate with a thickness of 0.7 mm and made of silicon;

[0093] S2, forming a plurality of cylindrical prefabricated holes arranged in a matrix on the crystal substrate of step S1 by laser drilling, wherein the laser pulse width used for laser drilling is 100 fs and the power is 3 W, and the average diameter of the prefabricated holes is 15 μm, the depth is 22 μm, and the spacing is 30 μm;

[0094] S3, immersing the crystal substrate with the prefabricated holes in step S2 into a potassium hydroxide solution with a mass concentration of 5% for etching for 40 minutes, so that the prefabricated holes are anisotropically etched to form inverted pyramid grooves (in an inverted pyramid structure), the depth of the inverted pyramid grooves is 30 μm, and the spacing is 30 μm;

[0095] S4. After cleaning and drying, the crystal substrate after etching in step S3 is subjected to laser irradiation treatment for 20 minutes to modify the surface of the inverted pyramid groove so that a microstructure is formed on the surface of the inverted pyramid groove. The surface material of the inverted pyramid groove is modified under laser irradiation to form intrinsic silicon particles, silicon oxide and silicon hydrate. The laser irradiation uses a laser pulse width of 100fs and a power of 2W. The microstructure includes a particle structure with an average particle size of 400nm and a groove structure with a width of 30μm and a depth of 30μm to prepare the black body.

[0096] Example 3

[0097] S1. Provide a crystalline substrate with a thickness of 0.7 mm and made of silicon;

[0098] S2, forming a plurality of cylindrical prefabricated holes arranged in a matrix on the crystal substrate of step S1 by laser drilling, wherein the laser pulse width used for laser drilling is 100 ps and the power is 3 W, and the average diameter of the prefabricated holes is 25 μm, the depth is 20 μm, and the spacing is 30 μm;

[0099] S3, immersing the crystal substrate with the prefabricated holes in step S2 into a potassium hydroxide solution with a mass concentration of 5% for etching for 40 minutes, so that the prefabricated holes are anisotropically etched to form inverted pyramid grooves (in an inverted pyramid structure), the depth of the inverted pyramid grooves is 25 μm, and the spacing is 30 μm;

[0100] S4. After cleaning and drying, the crystal substrate after etching in step S3 is subjected to laser irradiation treatment for 20 minutes to modify the surface of the inverted pyramid groove so that a microstructure is formed on the surface of the inverted pyramid groove. The surface material of the inverted pyramid groove is modified under laser irradiation to form intrinsic silicon particles, silicon oxide and silicon hydrate. The laser irradiation uses a laser pulse width of 100ps and a power of 0.5W. The microstructure includes a particle structure with an average particle size of 300nm and a groove structure with a width of 30μm and a depth of 25μm to prepare the black body.

[0101] Example 4

[0102] The black body was prepared according to the method of Example 1, except that the parameters of the laser drilling were adjusted so that the average diameter of the preformed holes was 5 μm.

[0103] Example 5

[0104] The black body was prepared according to the method of Example 1, except that the parameters of laser drilling were adjusted, and the average diameter of the prefabricated holes formed by the laser drilling was 25 μm.

[0105] Example 6

[0106] A black body was prepared according to the method of Example 1, except that the power of the laser irradiation was 2.5W.

[0107] Example 7

[0108] A black body was prepared according to the method of Example 1, except that the power of the laser irradiation was 0.1 W.

[0109] Comparative Example 1

[0110] A black body is prepared according to the method of Example 1, except that the laser irradiation treatment in step S4 is not performed.

[0111] Comparative Example 2

[0112] A light absorption structure including a plurality of inverted pyramid structures is formed on the surface of the copper substrate by a mechanical scratching method. The inverted pyramid structures are spaced 100 μm apart and have a depth of 200 μm.

[0113] The black bodies prepared in the above embodiments and comparative examples were subjected to performance tests, and the testing method included:

[0114] Emissivity test: The emissivity test was performed using a Fourier infrared spectrometer with an integrating sphere. The characterization band was 2.5 μm to 12 μm, the band test interval was 10 nm, and the obtained emissivity was averaged. The test results are shown in Table 1.

[0115] Stability test: After ultrasonic cleaning for 15 minutes, the prepared structured black body was placed in a 1000°C heating element for a heating aging test. The heating time was 3 hours. After cooling, the emissivity test was performed. The test results are shown in Table 1.

[0116] Table 1

[0117]

[0118] From the above table we can see that:

[0119] (1) Compared with Examples 4-5, it can be seen that the present application adopts appropriate laser drilling parameters so that the average diameter of the processed prefabricated holes is within a suitable range, which can ensure the formation of a complete inverted pyramid, avoid reflections caused by incomplete structures, and maximize the wave absorption effect of the structure.

[0120] (2) Compared with Examples 6-7, it can be seen that the present application controls the power of laser irradiation to ensure the formation of microstructures and modified materials on the surface of the inverted pyramid grooves, thereby avoiding the occurrence of problems such as insufficient surface microstructure density, uneven thickness of the modified layer, mismatch in specific gravity of the modified layer material components, and damage to the inverted pyramid material.

[0121] (3) Compared with Example 1-2, it can be seen that Example 2 uses a traditional copper substrate, which is limited by the processing form, and the size of the wave-absorbing structure formed is relatively large; if the size of Example 2 is further reduced, not only will the processing time be long, but the yield will also be low. However, the present application uses a crystal material as the substrate of the black body, and forms a microstructured inverted pyramid groove wave-absorbing structure on the surface of the crystal material, which cooperates to achieve a high wave-absorbing effect and has the stability of a structural black body. In addition, due to the high efficiency of wet etching technology, crystal materials are easier to process on a large area to form a wave-absorbing structure than metal materials such as copper. Therefore, the black body of the present application has the characteristics of high stability, good wave-absorbing effect and easy processing.

[0122] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0123] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the application. It should be noted that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A blackbody, characterized in that: The black body comprises a crystal substrate, the surface of the crystal substrate has a plurality of inverted pyramid grooves, the surface of the inverted pyramid grooves has a microstructure, the microstructure comprises a particle structure, and the average diameter of the particle structure is 300nm-400nm; A plurality of the inverted pyramid grooves are arranged in an array on the surface of the crystal substrate, and at least part of the surface of the inverted pyramid grooves includes a modified material layer; the material of the modified material layer includes at least one of an oxide and a hydrate; the depth of the inverted pyramid groove is 15 μm to 40 μm; and the spacing distance between adjacent inverted pyramid grooves is 20 μm to 40 μm.

2. The blackbody according to claim 1, characterized in that The material of the crystalline substrate includes at least one of silicon, germanium, silicon carbide and diamond.

3. A method for preparing a black body, characterized in that: The preparation method of the blackbody comprises: providing a crystalline substrate; A plurality of preformed holes are formed on the surface of the crystal substrate, the plurality of preformed holes are arranged in an array on the crystal substrate, the average diameter of the preformed holes is 10 μm to 20 μm, the depth is 10 μm to 30 μm; and the spacing between adjacent preformed holes is 20 μm to 40 μm; Using an etchant to etch the crystal substrate having the plurality of preformed holes, so as to anisotropically etch the preformed holes to form inverted pyramid grooves; Performing laser irradiation treatment on the crystalline substrate after the etching treatment, so that a microstructure is formed on the surface of the inverted pyramid groove, and a modified material layer is formed on at least a portion of the surface of the inverted pyramid groove; Wherein, the microstructure includes a particle structure, and the average diameter of the particle structure is 300nm~400nm; the material of the modified material layer includes at least one of an oxide and a hydrate.

4. The method for preparing a blackbody according to claim 3, characterized in that: The etchant includes at least one of an acid solution, an alkali solution, a salt solution and an organic solvent.

5. The method for preparing a black body according to claim 3, characterized in that: The laser irradiation treatment uses a laser with a pulse width of 1fs to 100ps and a power of 0.5W to 2W.

6. The method for preparing a blackbody according to any one of claims 3 to 5, characterized in that: The method of forming a plurality of prefabricated holes on the surface of the crystal substrate includes laser drilling; The laser opening uses a laser with a pulse width of 1fs to 100ps and a power of 2W to 5W.

7. Use of a black body as claimed in any one of claims 1 to 2 or a black body prepared by the method for preparing a black body as claimed in any one of claims 3 to 6 in preparing a thermal imaging device.

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