Metasurface material with high laser reflectivity as well as preparation method and application of metasurface material

Abstract

The invention provides a metasurface material with high laser reflectivity and a preparation method and application thereof, and relates to the technical field of laser reflecting materials. The super-surface material disclosed by the invention is obtained by constructing a super-structure micro-column array on a substrate; the super-structure micro-column is a silver micro-column; the height H of the micro-column array is 0.15-0.5 [mu] m, the diameter # imgabs0 # of the micro-column array is 0.2-0.5 [mu] m, and the distance D between adjacent arrays of the micro-column array is 0.1-1 [mu] m. Through precise design and construction of the super-structure micro-column array, the laser achieves extremely high reflectivity on the surface of the target, thermal ablation of the laser on the target can be effectively reduced, a stronger reflection effect can be provided when laser attack occurs, thermal damage and ablation caused by laser attack are greatly reduced, and the super-structure micro-column array is suitable for high-energy laser protection and also suitable for high-energy laser protection. And the method can play an important role in the fields of military, aerospace, laser processing, medical treatment and the like, and has wide adaptability.

Description

Technical Field

[0001] The present invention relates to the technical field of laser reflective materials, and in particular to a super surface material with high laser reflectivity, a preparation method thereof and an application thereof. Background Art

[0002] High-energy laser refers to a laser system with large output laser energy and high power. Its energy output is usually in the 10000 joules (10 4 Joules) level, with an average power of 10,000 watts (10 4 The working principle of high-energy laser is based on the principle of stimulated radiation and light amplification. When the electrons of microcolumns or molecules are excited to a high energy level and stimulated by photons of the same frequency, stimulated radiation will be generated, releasing photons of the same frequency, phase and direction as the incident photons, thus forming high-energy lasers. High-energy lasers have many advantages such as concentrated energy, fast transmission speed, high hitting accuracy, anti-electromagnetic interference, and high combat cost-effectiveness. They are new weapons that can effectively attack drones.

[0003] At present, one of the main means of high-energy laser strikes against drones is to irradiate the electronic systems and substrates inside the drones, causing the target to heat up rapidly, resulting in thermal ablation failure and burning of circuits and substrates. The traditional way to deal with high-energy laser strikes is either to use high-performance materials or to improve the material's resistance to high temperatures through protective coatings. Both of these passively resist the effects of lasers and have problems such as low protection thresholds and delayed thermal response. When encountering continuous or high-power laser irradiation, it is often difficult to avoid cumulative thermal damage to key components by simply relying on material upgrades, and the increase in weight and cost brought by high-performance materials will also significantly affect the maneuverability and economy of drones. Therefore, it is necessary to develop a method to reduce thermal ablation of lasers on targets from the source to overcome these problems. Summary of the invention

[0004] In view of this, the present invention is based on the bionic design concept and refers to the technical principle that the wings of insects such as ultra-white insects have extremely high reflectivity to light. It provides a super surface material with high laser reflectivity and its preparation method and application, which can achieve high reflection of laser on the target surface, reduce thermal ablation of laser on the target from the source, realize active defense against laser, and provide new ideas and new ways to deal with high-energy laser strikes.

[0005] The first aspect of the present invention is to provide a supersurface material with high laser reflectivity, wherein the supersurface material is obtained by constructing a superstructure micro-pillar array on a substrate;

[0006] The superstructure microcolumns are silver microcolumns, the height (H) of the microcolumn array is 0.15 to 0.5 μm, and the diameter of the microcolumn array is It is 0.2~0.5μm, and the adjacent array spacing of the microcolumn array is (D) 0.1~1μm.

[0007] A second aspect of the present invention is to provide a method for preparing a supersurface material with high laser reflectivity, which specifically comprises the following steps:

[0008] First, a metasurface design of a metastructured micro-pillar array is carried out, and then a mask model is inversely designed based on the designed array. After the metastructured micro-pillar array is formed on a substrate according to the design, in-situ annealing is performed, and after the in-situ annealing, a metasurface material with high laser reflectivity is obtained.

[0009] Preferably, the superstructure microcolumns are silver microcolumns, the H of the microcolumn array is 0.15 to 0.5 μm, and the The adjacent array spacing D of the microcolumn array is 0.1 to 1 μm.

[0010] Preferably, the metastructure microcolumn array is formed by magnetron sputtering.

[0011] Preferably, the in-situ annealing temperature is 200° C. to 400° C., the holding time is 1 to 3 hours, and after the holding is completed, the sample is naturally cooled to room temperature.

[0012] The third aspect of the present invention is to provide the application of the supersurface material with high laser reflectivity in the field of high-energy laser protection, and the supersurface material with high laser reflectivity is the supersurface material with high laser reflectivity described in the above scheme.

[0013] Compared with the prior art, the beneficial technical effects of the present invention are:

[0014] The present invention optimizes the reflective performance of the laser at the microscopic structure by precisely designing and constructing a super-structured micro-pillar array, so that the laser can achieve extremely high reflectivity on the target surface (the surface reflectivity for a 1064nm laser wavelength is greater than 90%). This can not only effectively reduce the thermal ablation of the target by the laser, but also provide a stronger reflection effect when a laser attack occurs, greatly reducing the thermal damage and ablation caused by laser strikes.

[0015] The present invention can effectively improve the crystal structure of the material through the in-situ annealing step, enhance the thermal stability and laser reflection ability of the supersurface material, and accurately control the arrangement and size of the superstructure microcolumns through magnetron sputtering technology, thereby achieving higher reflectivity in the microstructure of the material.

[0016] The supersurface material of the present invention is not only suitable for high-energy laser protection, but also can play an important role in the fields of military, aerospace, laser processing and medical treatment, and has wide adaptability.

[0017] Compared with traditional laser protection materials, the use of the metasurface material of the present invention can reduce the weight and volume of the overall equipment, which helps to achieve a lighter protection system in design and has lower preparation costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention will be further described below in conjunction with the accompanying drawings.

[0019] Figure 1 Schematic diagram of the surface structure of the supersurface material of Examples 1-3;

[0020] Figure 2 The reflectivity test result of the super surface material in Example 1;

[0021] Figure 3 The reflectivity test result of the super surface material in Example 2;

[0022] Figure 4 This is the reflectivity test result of the supersurface material of Example 3. DETAILED DESCRIPTION

[0023] The technical solution of the present invention will be clearly and completely described below in conjunction with 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.

[0024] The first aspect of the present invention is to provide a supersurface material with high laser reflectivity, wherein the supersurface material is obtained by constructing a superstructure micro-pillar array on a substrate.

[0025] The superstructure microcolumn of the present invention is a silver microcolumn, the H of the microcolumn array is 0.15-0.5 μm, and the The adjacent array spacing D of the microcolumn array is 0.1 to 1 μm.

[0026] In some specific embodiments of the present invention, the substrate material is a silicon wafer, and the diameter of the silicon wafer is 10 to 20 mm.

[0027] Silver has a very high optical reflectivity, especially in the visible and near-infrared spectral range, which makes silver microcolumns have unique advantages in laser reflection applications. Therefore, the present invention selects silver microcolumns as super-structured microcolumns. At the same time, the present invention selects super-structured atoms in the shape of microcolumns, and utilizes the surface plasmon resonance (SPR) effect of the microcolumn structure to enhance the laser reflectivity while avoiding reflection losses caused by rough or uneven surfaces.

[0028] In addition, the design of the present invention refers to the morphology of efficient reflective structures in nature. By strictly limiting parameters such as the height, diameter, spacing, and array arrangement of the micro-pillar array, the microstructure is optimized to achieve efficient optical reflection, thereby ensuring that the metasurface material has high laser reflectivity, structural stability, and manufacturability.

[0029] A second aspect of the present invention is to provide a method for preparing a supersurface material with high laser reflectivity, which specifically comprises the following steps:

[0030] S1. Design of superstructured micropillar array metasurface:

[0031] A superstructured microcolumn array is designed on a substrate, wherein the H of the microcolumn array is 0.15 to 0.5 μm, and the is 0.2-0.5 μm, and the adjacent array D of the micropillar array is 0.1-1 μm;

[0032] S2. Mask production:

[0033] Coating photoresist on the substrate, inversely designing a mask model according to the micro-pillar array designed in step S1, and then subjecting the substrate to ultraviolet light exposure to obtain a substrate with a pattern mask;

[0034] The thickness of the photoresist is 1-10 μm, the wavelength of the ultraviolet light is 355 nm, and the power of the ultraviolet light is 10000-100000 mW / cm 2 , the light exposure treatment time is 15 to 30 seconds;

[0035] In some specific embodiments of the present invention, the substrate is pretreated before use, and the pretreatment method is as follows: the substrate material is cleaned with anhydrous ethanol until the surface is clean and free of contamination;

[0036] S3, magnetron sputtering

[0037] The substrate with the pattern mask obtained in step S2 is placed in a magnetron sputtering vacuum chamber, and a silver target is formed into a superstructure microcolumn array by magnetron sputtering;

[0038] The purity of the silver target is 99.9%, and the vacuum degree of the vacuum chamber is 1.0×10 -4 ~5.0×10 -4 Pa; during the magnetron sputtering process, the mask faces the target material, the distance between the substrate and the sputtering target source is 1 to 5 cm, the magnetron sputtering temperature is 200°C to 400°C, the power is 10 to 50 W, and the magnetron sputtering deposition time is 1 to 3 hours; the magnetron sputtering is carried out in a high-purity argon atmosphere, the argon flow rate is 10 to 50 SCCM, and the gas pressure is 1 to 10 Pa;

[0039] In some specific embodiments of the present invention, pre-sputtering is performed before magnetron sputtering, and formal magnetron sputtering is performed after the glow is stable. The pre-sputtering time is generally 5 to 10 minutes, which can be adjusted according to specific circumstances;

[0040] S4, in-situ annealing

[0041] After the magnetron sputtering is completed, the sputtering power supply is turned off, and the material is in-situ annealed in an argon atmosphere. After the in-situ annealing is completed, a metasurface material with high laser reflectivity is obtained;

[0042] The in-situ annealing temperature is 200° C. to 400° C., the holding time is 1 to 3 hours, and the sample is naturally cooled to room temperature after the holding is completed.

[0043] The third aspect of the present invention is to provide the application of the supersurface material with high laser reflectivity in the field of high-energy laser protection.

[0044] The super surface material of the present invention is based on the bionic design principle and realizes efficient reflection of laser by designing microstructure.

[0045] Metasurface materials with high laser reflectivity are based on bionic materials and mainly achieve efficient reflection of lasers by designing microstructures. Therefore, they have broad application prospects in the field of high-energy laser protection.

[0046] For example, it can be used to prepare protective materials that protect sensitive equipment, weapon systems, spacecraft, etc. from laser attacks or laser ablation damage; it can be used to prepare laser protective covers and other protective equipment; it can be used to prepare high-precision optical equipment, such as laser scanners, laser microscopes, etc., to effectively protect the equipment from laser damage and extend the service life of the equipment; in material processing and energy production equipment, it can be used to reflect excess laser to prevent the equipment from overheating or damage.

[0047] In order to further illustrate the present invention, the following examples are provided for detailed description. The raw materials used in the following examples of the present invention are all commercially available.

[0048] Unless otherwise specified, all experiments were repeated 3 times and the results were expressed as mean values.

[0049] Embodiment 1 A method for preparing a super surface material with high laser reflectivity, comprising the following steps:

[0050] S1. Design a silver microcolumn array, where the H of the microcolumn array is 0.20 μm and the The adjacent array D of the micro-pillar array is 0.30 μm, and the adjacent array D of the micro-pillar array is 0.50 μm. The arrangement of the silver micro-pillar array is as follows Figure 1 As shown;

[0051] S2, cleaning a silicon wafer with a diameter of 10 mm in anhydrous ethanol to ensure that the surface is clean and free of contamination before using it as a substrate;

[0052] S3. According to the designed micro-pillar array, the mask model is reversely designed, and a photoresist with a thickness of 1 μm is coated on the substrate. Then, the substrate is exposed to ultraviolet light with a wavelength of 355 nm for 15 seconds, and the exposure power is 12000 mW / cm 2 , obtaining a substrate with a pattern mask;

[0053] S4. Place the substrate with the pattern mask obtained in S3 in a magnetron sputtering vacuum chamber, use a silver target with a purity of 99.9%, and place the pattern mask toward the target. Adjust the distance between the substrate and the sputtering target source to 2 cm, and start evacuating until the vacuum reaches 1.0×10 -4 Pa, turn on the heating temperature control power supply, set the heating temperature to 200 ° C, start heating the substrate, turn on the gas flow controller and sputtering power supply for preheating, and turn on the sample stage rotation at 30 rpm. After the temperature rises to the predetermined temperature, introduce high-purity argon gas, fix the argon gas flow rate to 10 SCCM, and adjust the gas pressure to the predetermined working pressure of 1 Pa, adjust the sputtering power to 10 W, pre-sputter for 5 minutes, open the baffle and start sputtering after the glow is stable, and the deposition time is 1 hour;

[0054] S5. After the sputtering is completed, the sputtering power is turned off, the sample after magnetron sputtering is placed in a magnetron sputtering device, and the film is in-situ annealed under an argon atmosphere. The in-situ annealing temperature is 200°C and the insulation time is 1 hour. After the insulation is completed, it is naturally cooled to room temperature to obtain a supersurface material with high laser reflectivity.

[0055] According to the test, the surface reflectivity of the supersurface material prepared in this embodiment for a laser wavelength of 1064 nm is 93.1%.

[0056] Embodiment 2 A method for preparing a super surface material with high laser reflectivity, the steps are as follows:

[0057] S1. Design a silver microcolumn array, where the H of the microcolumn array is 0.20 μm and the The distance D between adjacent micropillar arrays is 0.50 μm. The arrangement of the silver micropillar array is as follows: Figure 1 As shown;

[0058] S2, cleaning a silicon wafer with a diameter of 10 mm in anhydrous ethanol to ensure that the surface is clean and free of contamination before using it as a substrate;

[0059] S3. According to the designed micro-pillar array, the mask model is reversely designed, and a photoresist with a thickness of 1.5 μm is coated on the substrate. Then, the substrate is exposed to ultraviolet light with a wavelength of 355 nm for 20 seconds, and the exposure power is 10500 mW / cm 2 , obtaining a substrate with a pattern mask;

[0060] S4. Place the substrate with the pattern mask obtained in S3 in a magnetron sputtering vacuum chamber, use a silver target with a purity of 99.9%, with the pattern mask facing the target, adjust the distance between the substrate and the sputtering target source to 3 cm, and start evacuating until the vacuum degree reaches 2.0×10 -4 Pa, turn on the heating temperature control power supply, set the heating temperature to 250 ° C, start heating the substrate, turn on the gas flow controller and sputtering power supply for preheating, and turn on the sample stage rotation at 30 rpm. After the temperature rises to the predetermined temperature, introduce high-purity argon gas, fix the argon gas flow rate to 18 SCCM, and adjust the gas pressure to the predetermined working pressure of 1 Pa, adjust the sputtering power to 20 W, pre-sputter for 10 minutes, open the baffle and start sputtering after the glow is stable, and the deposition time is 2 hours;

[0061] S5. After the sputtering is completed, the sputtering power is turned off, the sample after magnetron sputtering is placed in a magnetron sputtering device, and the film is in-situ annealed under an argon atmosphere. The in-situ annealing temperature is 300°C and the insulation time is 2h. After the insulation is completed, it is naturally cooled to room temperature to obtain a supersurface material with high laser reflectivity.

[0062] According to the test, the surface reflectivity of the supersurface material prepared in this embodiment for a laser wavelength of 1064 nm is 92.5%.

[0063] Embodiment 3 A method for preparing a super surface material with high laser reflectivity, the steps are as follows:

[0064] S1. Design a silver microcolumn array, where the H of the microcolumn array is 0.25 μm and the The distance D between adjacent micropillar arrays is 0.50 μm. The arrangement of the silver micropillar array is as follows: Figure 1 As shown;

[0065] S2, cleaning a silicon wafer with a diameter of 10 mm in anhydrous ethanol to ensure that the surface is clean and free of contamination before using it as a substrate;

[0066] S3. According to the designed micro-pillar array, the mask model is reversely designed, and a photoresist with a thickness of 2 μm is coated on the substrate. Then, the substrate is exposed to ultraviolet light with a wavelength of 355 nm for 30 seconds, and the exposure power is 20000 mW / cm 2 , obtaining a substrate with a pattern mask;

[0067] S4, placing the substrate with the pattern mask obtained in S3 in a magnetron sputtering vacuum chamber, using a silver target with a purity of 99.9%, with the pattern mask facing the target, adjusting the distance between the substrate and the sputtering target source to 2 cm, and starting to evacuate until the vacuum degree reaches 3.0×10 -4 Pa, turn on the heating temperature control power supply, set the heating temperature to 300 ° C, start heating the substrate, turn on the gas flow controller and sputtering power supply for preheating, and turn on the sample stage rotation at 30 rpm. After the temperature rises to the predetermined temperature, introduce high-purity argon gas, fix the argon gas flow rate to 20 SCCM, and adjust the gas pressure to the predetermined working pressure of 5 Pa, adjust the sputtering power to 20 W, pre-sputter for 10 minutes, open the baffle and start sputtering after the glow is stable, and the deposition time is 2 hours;

[0068] S5. After the sputtering is completed, the sputtering power is turned off, the sample after magnetron sputtering is placed in a magnetron sputtering device, and the film is in-situ annealed under an argon atmosphere. The in-situ annealing temperature is 400°C and the insulation time is 3 hours. After the insulation is completed, it is naturally cooled to room temperature to obtain a supersurface material with high laser reflectivity.

[0069] According to the test, the surface reflectivity of the supersurface material prepared in this embodiment is 90.3% for the 1064nm laser wavelength.

[0070] Comparative Example 1

[0071] Same as Example 1, except that the H of the micro-pillar array is 0.5.

[0072] After testing, the surface reflectivity of the supersurface material prepared in this comparative example for a laser wavelength of 1064 nm is 87.2%.

[0073] Comparative Example 2

[0074] Same as Example 1, except that: is 0.2.

[0075] After testing, the surface reflectivity of the supersurface material prepared in this comparative example for a laser wavelength of 1064 nm is 87.4%.

[0076] Comparative Example 3

[0077] Same as Example 1, except that the distance D between adjacent arrays of the micro-pillar array is 0.05.

[0078] After testing, the surface reflectivity of the supersurface material prepared in this comparative example for a laser wavelength of 1064 nm is 86.5%.

[0079] Comparative Example 4

[0080] Same as Example 1, except that the H of the micro-pillar array is 1.0.

[0081] After testing, the surface reflectivity of the supersurface material prepared in this comparative example is 87.8% for a laser wavelength of 1064 nm.

[0082] Comparative Example 5

[0083] Same as Example 1, except that: is 1.0.

[0084] After testing, the surface reflectivity of the supersurface material prepared in this comparative example for a laser wavelength of 1064 nm is 86.0%.

[0085] Comparative Example 6

[0086] Same as Example 1, except that the distance D between adjacent arrays of the micro-pillar array is 1.5.

[0087] After testing, the surface reflectivity of the supersurface material prepared in this comparative example for a laser wavelength of 1064 nm is 85.9%.

[0088] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A metasurface material with high laser reflectivity, characterized in that: The super surface material is obtained by constructing a super structure micro column array on a substrate; The superstructure microcolumn is a silver microcolumn; The height H of the micro-pillar array is 0.15-0.5 μm, and the diameter of the micro-pillar array is The microcolumn array has a spacing D of 0.2 to 0.5 μm and an adjacent array spacing D of 0.1 to 1 μm.

2. The supersurface material with high laser reflectivity according to claim 1, characterized in that: The substrate is a silicon wafer.

3. The super-surface material with high laser reflectivity according to claim 2, characterized in that: The diameter of the silicon wafer is 10 to 20 mm.

4. The method for preparing a supersurface material with high laser reflectivity according to any one of claims 1 to 3, characterized in that: The following steps are involved: First, a metasurface design of a metastructured micro-pillar array is carried out, and then a mask model is inversely designed based on the designed array. After the metastructured micro-pillar array is formed on a substrate according to the design, in-situ annealing is performed, and after the in-situ annealing, a metasurface material with high laser reflectivity is obtained.

5. The preparation method according to claim 4, characterized in that: The superstructure microcolumns are silver microcolumns, the height H of the microcolumn array is 0.15 to 0.5 μm, and the diameter of the microcolumn array is The adjacent array spacing D of the microcolumn array is 0.1 to 1 μm.

6. The preparation method according to claim 4, characterized in that: The superstructure microcolumn array is formed by magnetron sputtering.

7. The preparation method according to claim 6, characterized in that: The temperature of the magnetron sputtering is 200° C. to 400° C., and the power is 10 to 50W.

8. The preparation method according to claim 6, characterized in that: The magnetron sputtering deposition time is 1 to 3 hours.

9. The preparation method according to claim 2, characterized in that: The in-situ annealing temperature is 200° C. to 400° C., the holding time is 1 to 3 hours, and the sample is naturally cooled to room temperature after the holding is completed.

10. Application of a metasurface material with high laser reflectivity in the field of high-energy laser protection, characterized in that: The supersurface material with high laser reflectivity is the supersurface material with high laser reflectivity described in any one of claims 1 to 3 or the supersurface material with high laser reflectivity prepared by the method described in any one of claims 4 to 9.

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