A vein-imitated wear-resistant ultra-wideband anti-reflection film structure and a preparation method thereof

Abstract

The application discloses a kind of wear-resistant ultra-wideband antireflection film structure of imitative leaf vein and preparation method thereof, it is related to optical thin film technical field.The wear-resistant ultra-wideband antireflection film structure of imitative leaf vein includes surface protruding imitative leaf vein structure, hard layer covered on the imitative leaf vein structure and ultra-wideband antireflection film covered on the hard layer;The ratio of the refractive index of the hard layer and the refractive index of the imitative leaf vein structure is 0.95~1.05:1;The thickness of the ultra-wideband antireflection film is not more than 50 μm.The wear-resistant ultra-wideband antireflection film structure of imitative leaf vein of the application significantly enhances the wear resistance and reliability of antireflection film: imitative leaf vein structure changes contact mode, actively protects the porous ultra-low refractive index film below, ensures its stable performance under mechanical action such as friction, wiping, prolongs service life.

Description

Technical Field

[0001] This invention relates to the field of optical thin film technology, and in particular to a wear-resistant ultrawideband antireflective film structure that mimics leaf veins and its preparation method. Background Technology

[0002] In the pursuit of higher energy capture efficiency in photovoltaic systems and energy-saving designs for high-latitude insulated buildings, enhancing the transmission performance of interfacial light across a wide spectral range is a core element in optimizing overall energy efficiency and environmental adaptability. Ultra-wideband antireflective coatings, as functional layers capable of effectively modulating interfacial optical properties, can significantly suppress Fresnel reflection losses caused by refractive index mismatch across a wide spectral range, thereby enhancing optical transmittance from the visible to near-infrared bands.

[0003] To meet the technical requirements of ultra-wideband and high-efficiency antireflection, introducing porous low-refractive-index films with nanograss-like or similar microstructures has become one of the solutions to achieve an equivalent refractive index gradient transition and break through the performance bottleneck of traditional film systems. These micro / nano structures, by forming a continuous air-medium mixture phase inside and on their surface, can effectively reduce the surface refractive index to extremely low levels, thereby achieving a near-perfect antireflection effect over an extremely wide spectral band.

[0004] However, this technological approach faces a severe challenge: the nanostructures constituting porous, low-refractive-index films are inherently physically fragile. Their enormous specific surface area and delicate microstructure make them highly susceptible to damage or structural collapse under conventional mechanical forces such as outdoor dust, raindrop erosion, and cleaning. This lack of mechanical durability leads to a sharp decline in antireflective properties, severely limiting the reliable application of such high-performance optical films in harsh or long-lifecycle environments. Therefore, how to significantly enhance the mechanical robustness and wear resistance of the film structure while maintaining ultra-wideband antireflective performance has become a crucial technical problem urgently needing to be solved in this field. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of traditional ultra-wideband antireflection film, which is difficult to balance with wear resistance and long lifespan, and to provide a leaf vein-inspired wear-resistant ultra-wideband antireflection film structure and its preparation method.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A wear-resistant ultra-wideband antireflective film structure with leaf vein-like features includes a leaf vein-like structure with protruding surfaces, a hardened layer covering the leaf vein-like structure, and an ultra-wideband antireflective film covering the hardened layer.

[0008] The ratio of the refractive index of the hardened layer to the refractive index of the leaf vein-like structure is 0.95~1.05:1; the thickness of the ultra-wideband antireflective coating is no greater than 50μm.

[0009] The leaf vein-like structure is composed of multi-level micro-nano lines with different widths and heights, wherein the height of the micro-nano lines is 0.5-20 μm and the width of the micro-nano lines is 0.5-20 μm.

[0010] The material of the leaf vein-like structure includes one or more of epoxy resin, UV-curable adhesive, polydimethylsiloxane, tetrafluoroethylene, and transparent Teflon.

[0011] The hardened layer is a nanolayer composed of high and low refractive index films in a specific ratio, and the film structure of the hardened layer is as follows: ,in, This represents a high-refractive-index film with a physical thickness of a nm. This represents a low-refractive-index film with a physical thickness of b nm, where x represents aH. p and bL p The number of floors;

[0012] Among them, high refractive index film is a film with a refractive index of not less than 1.6, and low refractive index film is a film with a refractive index of not more than 1.5.

[0013] The ultra-wideband antireflective coating comprises a stacked film layer composed of high and low refractive index films and a porous ultra-low refractive index film located on the surface of the stacked film layer. The stacked film layer is composed of multiple high refractive index films and low refractive index films in a certain proportion. The refractive index of the ultra-wideband antireflective coating is determined according to the target spectral range and the refractive index of the leaf vein-like structure. The refractive index of the high refractive index film layer is not less than 2, the refractive index of the low refractive index film layer is not greater than 1.5, and the refractive index of the porous ultra-low refractive index film is in the range of 1-1.3.

[0014] The film structure of the ultra-wideband antireflection film is as follows: ,in, This represents a high-refractive-index film with a physical thickness of c nm. This represents a low-refractive-index film with a physical thickness of d nm. This represents a porous ultra-low refractive index film with a physical thickness of e nm, where y represents... and The number of floors.

[0015] The film structure of the ultra-wideband antireflection film is as follows: ,in, This represents a high-refractive-index film with a physical thickness of c nm. This represents a low-refractive-index film with a physical thickness of d nm. This represents a high-refractive-index film with a physical thickness of g nm. This represents a low-refractive-index film with a physical thickness of h nm. This represents a porous ultra-low refractive index film with a physical thickness of 100 nm.

[0016] The leaf vein-like structure includes a planar layer and surface protrusions, wherein the thickness of the planar layer is 20-500 μm.

[0017] The above-mentioned method for preparing the wear-resistant ultrawide antireflective film structure with leaf vein-like appearance includes the following steps:

[0018] S1: Preparation of leaf vein-like structures;

[0019] S2: Prepare a hardened layer on the surface of the leaf vein-like structure;

[0020] S3: Prepare an ultrawideband antireflection film on the surface of the hardened layer;

[0021] Specifically, step S1, which involves preparing the leaf vein-like structure, includes the following steps:

[0022] S11: Photolithography substrate with leaf vein-like structure fabricated using photolithography technology;

[0023] S12: Using the leaf vein-like photolithography substrate obtained in step S11, prepare a leaf vein-like mold.

[0024] S13: The leaf vein-like structure is prepared using nanoimprinting technology with the leaf vein-like structure mold.

[0025] Specifically, step S3, which involves preparing an ultrawideband antireflection film on the surface of the hardened layer, includes the following steps:

[0026] S31: A stacked film layer composed of high and low refractive index films is prepared using atomic layer deposition technology;

[0027] S32: Prepare an Al2O3 thin film on the outer layer of the stacked film layers;

[0028] S33: The surface Al2O3 film is transformed into a grass-like alumina structure using a hot water bath. Atomic layer deposition (ALD) is then used to prepare a nanometer-thick SiO2 or Al2O3 layer on the surface of the grass-like alumina structure, followed by curing. Specifically, the nanometer-thick SiO2 or Al2O3 layer is 0.5-1.8 nm thick. In this embodiment, the cured layer and the grass-like alumina structure are collectively referred to as a porous ultra-low refractive index film.

[0029] The beneficial effects of this invention are as follows:

[0030] (1) The wear-resistant ultra-wideband anti-reflection film structure of the present invention, which imitates leaf veins, achieves efficient omnidirectional broadband anti-reflection: through the synergistic effect of the stacked film design and the porous ultra-low refractive index structure on the surface, it exhibits extremely low reflectivity in a wide spectral range, which significantly improves the transmission efficiency of the optical system.

[0031] (2) The wear-resistant ultra-wideband anti-reflective film structure of the present invention significantly enhances the wear resistance and reliability of the anti-reflective film: the leaf vein structure actively protects the underlying porous ultra-low refractive index film by changing the contact mode, ensuring its stable performance under mechanical action such as friction and wiping, and extending its service life.

[0032] (3) The wear-resistant ultra-wideband anti-reflective film structure of the present invention realizes the reinforcement of the organic imitation leaf vein structure through the hardening layer: the unique hardening layer design enhances the mechanical strength of the organic imitation leaf vein structure while ensuring optical performance, so that the imitation leaf vein structure has both excellent biomimetic protection function and excellent mechanical durability. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the wear-resistant ultrawide antireflective film structure of the leaf vein-inspired design of the present invention;

[0034] Figure 2 The design and fabrication process of the leaf vein-inspired wear-resistant ultrawideband antireflective film structure of the present invention;

[0035] Figure 3 This is a three-dimensional design drawing of the leaf vein-like structure in Example 1;

[0036] Figure 4 The theoretical optical performance analysis diagram of the 400-1100 nm ultrawideband antireflection coating in Example 1 is shown.

[0037] Figure 5 The transmittance analysis diagram of the 400-1100 nm ultrawideband antireflection film under different incident angles obtained from the simulation in Example 1 is shown.

[0038] Figure 6 Microscopic photograph of the leaf vein-like structure prepared in Example 1;

[0039] Figure 7 Scanning electron microscope image of the cross-sectional morphology of the ultrawideband antireflection film prepared in Example 1;

[0040] Figure 8 This is a schematic diagram of the optical performance test results of the 400-1100 nm band leaf vein-inspired wear-resistant ultrawideband antireflective film structure prepared in Example 1.

[0041] Figure 9This is a theoretical optical performance analysis diagram of the 1000-1700 nm ultrawideband antireflection coating in Example 2;

[0042] Figure 10 The image shows the transmittance analysis of the 1000-1700 nm ultrawideband antireflection film at different incident angles, obtained from simulation in Example 2.

[0043] The attached figures are labeled as follows: 1-Ultra-wideband antireflective coating, 2-Curing layer, 3-Imitation leaf vein structure, 4-Substrate. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0045] The principle behind the wear-resistant ultra-wideband anti-reflective film structure mimicking leaf veins of this invention is as follows:

[0046] (1) The principle of ultra-wideband antireflection film: the equivalent refractive index is gradually changed by stacked film layers composed of high and low refractive index films, thus broadening the antireflection bandwidth; the surface porous ultra-low refractive index film utilizes the air-medium mixed phase formed by the nano-grass structure to reduce the interface refractive index to near that of air, thus achieving efficient antireflection in a wide band.

[0047] The ultra-wideband antireflective coating comprises a stacked film layer composed of high and low refractive index films and a porous ultra-low refractive index film located on the surface of the stacked film layer. The stacked film layer is composed of multiple high refractive index films and low refractive index films in a certain proportion. The refractive index of the ultra-wideband antireflective coating is determined according to the target spectral range and the refractive index of the leaf vein-like structure. The refractive index of the high refractive index film layer is not less than 2, the refractive index of the low refractive index film layer is not greater than 1.5, and the refractive index of the porous ultra-low refractive index film is in the range of 1-1.3.

[0048] Specifically, the refractive index of the ultra-wideband antireflection film is determined based on the target spectral range and the refractive index of the leaf vein-like structure. Then, the materials for the high-refractive-index film layer and the low-refractive-index film layer are selected. Based on the refractive index of the ultra-wideband antireflection film, the refractive index of the selected high-refractive-index film layer, the refractive index of the selected low-refractive-index film layer, and the refractive index of the porous ultra-low refractive-index film, the film system structure of the ultra-wideband antireflection film is designed.

[0049] Based on the target spectral range and the refractive index of the leaf vein-like structure, and using Fresnel's law, high-refractive-index and low-refractive-index films with different refractive indices are selected, and the initial film system structure (i.e., ).

[0050] The film structure of the ultra-wideband antireflection film is as follows: ,in, This represents a high-refractive-index film with a physical thickness of c nm. This represents a low-refractive-index film with a physical thickness of d nm. This represents a porous ultra-low refractive index film with a physical thickness of e nm, where y represents... and The number of layers. In this embodiment, the multiple high-refractive-index films have the same thickness, and the multiple low-refractive-index films have the same thickness.

[0051] Alternatively, the film structure of the ultrawideband antireflection film is as follows: ,in, This represents a high-refractive-index film with a physical thickness of c nm. This represents a low-refractive-index film with a physical thickness of d nm. This represents a high-refractive-index film with a physical thickness of g nm. This represents a low-refractive-index film with a physical thickness of h nm. This represents a porous ultra-low refractive index film with a physical thickness of 10 nm. In this embodiment, the thicknesses of the multiple high refractive index layers are not entirely the same, and the thicknesses of the multiple low refractive index layers are also not entirely the same.

[0052] (2) Protection principle of leaf vein imitation structure: The leaf vein imitation structure of the present invention makes the higher leaf veins bear friction preferentially, which can change the external wear from surface contact to point / line contact, and significantly reduce the wear area of ​​the fragile porous membrane.

[0053] (3) Design principle of hardening layer: The nano-layer with refractive index equivalent to that of leaf vein structure is formed by matching the thickness of high and low refractive index films in proportion. While ensuring optical matching with the bottom layer to reduce reflection, it can effectively improve the hardness, elastic modulus and overall structural robustness of organic leaf vein substrate.

[0054] The leaf vein-inspired wear-resistant ultra-wideband anti-reflective film structure of the present invention includes a leaf vein-inspired structure with protruding surface, a hardened layer covering the leaf vein-inspired structure, and an ultra-wideband anti-reflective film covering the hardened layer.

[0055] The surface protrusions of the leaf vein-like structure are preferably multiple isosceles triangles with different heights and widths, more preferably equilateral triangles. The surface protrusions located at the edges are the tallest, and the heights of adjacent surface protrusions are preferably different to form an undulating surface protrusion pattern.

[0056] Example 1:

[0057] To address the needs of silicon-based photovoltaic power generation and solar thermal gain in buildings in high-latitude regions, this embodiment designs and fabricates a wear-resistant, ultra-wideband antireflective coating structure with leaf vein-like characteristics in the 400-1100 nm wavelength range. Its structure is as follows: Figure 1 As shown, from top to bottom, it includes an ultra-wideband antireflective film 1, a hardening layer 2, a leaf vein-like structure 3, and a substrate 4.

[0058] Design and fabrication process as follows Figure 2 As shown, the details are as follows:

[0059] Based on the technical problem to be solved—the requirement of mechanical stability—this invention first designed a leaf vein-like structure model, and used photolithography to prepare a leaf vein-like structure photolithography substrate. Then, using nanoimprinting technology, a leaf vein-like structure 3 was prepared on substrate 4. Next, according to the refractive index requirements of the hardened layer 2, the film structure of the hardened layer 2 was designed. Based on the target spectral range and the optical constant—refractive index—of the leaf vein-like structure 3, the film structure of the ultra-wideband antireflection film 1 was optimized through simulation calculation. Then, the hardened layer 2 and the ultra-wideband antireflection film 1 were deposited by atomic layer deposition. Finally, water dissolution and curing were performed to obtain a porous ultra-low refractive index film, ultimately obtaining a wear-resistant ultra-wideband antireflection film structure with leaf vein-like characteristics.

[0060] The structure of the wear-resistant ultra-wideband anti-reflection film structure mimicking leaf veins in this embodiment is as follows:

[0061] like Figure 3 As shown, based on the optical and mechanical stability requirements of the ultra-wideband antireflective film 1, this embodiment uses micro / nano lines with equilateral triangular cross-sectional morphology, with heights of 1.4 μm, 2.8 μm, 5.7 μm, and 11.4 μm, and widths of 2 μm, 4 μm, 8 μm, and 16 μm, respectively. These micro / nano lines are arranged in an alternating pattern to form equilateral triangles with side lengths of 20 μm, 40 μm, 80 μm, and 160 μm to improve the stability of the leaf vein-like structure. Simultaneously, when dealing with mechanical wear, the taller micro / nano lines can effectively protect the shorter nano lines below, effectively reducing wear on the film surface. The refractive index of the leaf vein-like structure 3 is determined by the properties of the substrate itself; the UV-curable adhesive used in this embodiment has a refractive index of 1.56.

[0062] Based on the optical constants of the leaf vein-like structure 3 material in this embodiment (optical constants of the UV-curable adhesive - refractive index 1.56), a filmWizard was used to design a structure based on the equivalent refractive index using L... p Layer (low refractive index SiO2) and H p The film system composed of layers (high refractive index Al2O3) is (10H p 15L p ) 20The high and low refractive index films are composed of a nano-stack in proportion, which serves as a hardened layer 2 with the same refractive index as the leaf vein-like structure.

[0063] Based on the target spectral range (400-1100 nm) and the optical constant of the leaf vein-like structure 3 material (the optical constant of the UV-curable adhesive is 1.56), a material composed of L... p Layer (low refractive index SiO2), H p Layer (high refractive index TiO2) and M p Composed of layers (grass-like alumina structure) (5H) p 60L p )4 200M p The multilayer membrane system was optimized through simulation calculations to obtain a membrane structure of 4H. p 60L p 12H p 60L p 16H p 60L p 12H p 120L p 210M p The ultra-wideband antireflective coating 1 has the following optical properties: Figure 4 As shown, its average transmittance reaches 99.5% in the 400-1100nm spectral range.

[0064] Considering the scenario of sunlight illuminating photovoltaic cells and buildings at large angles in high-latitude regions, the transmittance of the ultra-wideband antireflective coating at different incident angles was simulated and calculated, such as... Figure 5 As shown, its transmittance did not decrease significantly at incident angles of 10°-50°.

[0065] Based on the above design, the fabrication method of the wear-resistant ultrawideband antireflective coating structure with leaf vein-like features in the 400-1100 nm wavelength band is as follows:

[0066] (1) Based on the designed leaf vein structure 3, the designed pattern was prepared by two-photon laser direct writing technology.

[0067] (2) Then, first soak the substrate in PGMEA for 20 minutes, then transfer it to IPA for 10 minutes to wash away the photoresist and obtain the photolithography substrate.

[0068] (3) Mix polydimethylsiloxane and curing agent thoroughly at a weight ratio of 10:1 and let stand for 2 h until all air bubbles in the mixture are removed. Drop polydimethylsiloxane onto a photolithography substrate and heat it in an oven at 90 °C for 2 h. Manually peel off the PDMS to obtain a leaf vein-like structured mold.

[0069] (4) Apply UV-curable adhesive to the surface of substrate 4 (the substrate in this embodiment is glass), and press the leaf vein-like structural mold onto the surface of the UV-curable adhesive, scraping off any excess UV-curable adhesive around the edges. Irradiate the UV-curable adhesive with a 365 nm UV lamp for about 5 minutes. After the UV-curable adhesive has cured, peel off the leaf vein-like structural mold to obtain the final product as shown. Figure 6 The leaf vein-like structure shown is 3.

[0070] (5) The designed hardened layer 2 was deposited using atomic layer deposition technology. The process materials were: bis(tert-butylamino)silane (BTBAS) and plasma as the reaction precursors of the SiO2 layer, and trimethylaluminum (TMA) and plasma as the reaction precursors of the Al2O3 initial layer. The deposition process was carried out in a constant temperature chamber at 80 °C.

[0071] (6) The ultra-wideband antireflective film designed was deposited using atomic layer deposition technology. The process materials were: bis(tert-butylamino)silane (BTBAS) and plasma as the reaction precursor of SiO2 layer, titanium tetrachloride (TiCl4) and plasma as the reaction precursor of TiO2 layer, and trimethylaluminum (TMA) and plasma as the reaction precursor of Al2O3 layer. The deposition process was carried out in a constant temperature chamber at 80 °C.

[0072] (7) After atomic layer deposition, the sample was immersed in deionized water at 90 °C for 30 min. This process caused the outermost Al2O3 to undergo a hydration reaction and self-assemble into a layer such as... Figure 7 The grass-like alumina structure shown.

[0073] (8) Finally, an atomic layer deposition technique was used to deposit a nano-thickness of SiO2 on the surface of the grass-like alumina structure and then cured to obtain a wear-resistant ultra-wideband anti-reflection film structure with leaf veins in the 400-1100 nm band.

[0074] After preparation, the spectral transmittance of the sample was measured using an integrating sphere spectrometer. The test results are as follows: Figure 8 As shown, its actual optical performance is verified. From Figure 8 It can be seen that, within the wavelength range of 400-1100 nm, the transmittance of the leaf vein-inspired wear-resistant ultrawideband antireflective film structure prepared in this embodiment is basically above 99%.

[0075] Example 2:

[0076] The 1000-1700 nm band is a commonly used band for tandem solar cells. In this embodiment, a wear-resistant ultrawideband antireflective coating structure with leaf vein-like characteristics in the 1000-1700 nm band was designed and fabricated.

[0077] The structure of the wear-resistant ultra-wideband anti-reflection film structure mimicking leaf veins in this embodiment is as follows:

[0078] Based on the optical and mechanical stability requirements of the antireflective coating, this embodiment employs micro / nano lines with isosceles right-angled triangular cross-sectional shapes, with heights of 1 μm, 2 μm, 4 μm, and 8 μm, and widths of 2 μm, 4 μm, 8 μm, and 16 μm, respectively. These micro / nano lines are arranged in an alternating pattern to form equilateral triangles with side lengths of 15 μm, 30 μm, 60 μm, and 120 μm to improve the stability of the leaf vein structure. Simultaneously, in the face of mechanical wear, the taller micro / nano lines effectively protect the lower-height nano lines below, effectively reducing wear on the coating surface.

[0079] Based on the optical constant of the leaf vein-like structural material in this embodiment (the optical constant of epoxy resin is 1.58), a material with an equivalent refractive index of L was designed. p Layer (low refractive index SiO2) and H p The film system consists of layers (high refractive index TiO2) and is composed of (4H) p 21L p ) 20 The high and low refractive index films are composed of a nano-stack in proportion, which serves as a hardened layer with the same refractive index as the leaf vein structure.

[0080] Based on the target spectral range (1000-1700 nm) and the optical constant of the leaf vein-like structural material (the optical constant of epoxy resin is 1.58) of this embodiment, a material composed of L... p Layer (low refractive index SiO2), H p Layer (high refractive index Al2O3) and M p Composed of layers (grass-like alumina structure) (100H) p 60L p )2 200M p The multilayer membrane system was optimized through simulation calculations to obtain a membrane structure of 300H. p 60L p 21H p 60L p 300M p The ultra-wideband antireflective coating has optical properties such as Figure 9 As shown, its average transmittance reaches 99.3% in the 1000-1700 nm spectral range.

[0081] Considering the actual operation of photovoltaic modules, sunlight grazing into the solar cells was simulated and calculated to determine the transmittance of the ultra-wideband antireflection coating at different incident angles, such as... Figure 10 As shown, its transmittance did not decrease significantly at incident angles of 10°-50°.

[0082] Based on the above design, a wear-resistant ultrawideband antireflective film structure with leaf vein-like structure in the 1000-1700 nm band was prepared using the same method as in Example 1.

[0083] This invention integrates a leaf vein-like structure and an anti-reflective film on a substrate. The leaf vein-like structure reduces environmental wear on the anti-reflective film, while the anti-reflective film effectively reduces reflection from the substrate and the leaf vein structure. This provides a feasible technical path for the long-term stable use of ultra-wideband anti-reflective films in harsh environments.

[0084] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0085] The parts of this invention not described in detail are well-known in the art. The above embodiments are provided merely for the purpose of describing the invention and are not intended to limit the scope of the invention. The scope of the invention is defined by the appended claims. All equivalent substitutions and modifications made without departing from the spirit and principles of the invention should be covered within the scope of the invention.

Claims

1. A wear-resistant ultrawide antireflective film structure mimicking leaf veins, characterized in that, The wear-resistant ultra-wideband anti-reflective film structure with leaf vein-like features includes a leaf vein-like structure with protruding surface, a hardened layer covering the leaf vein-like structure, and an ultra-wideband anti-reflective film covering the hardened layer. The ratio of the refractive index of the hardened layer to the refractive index of the leaf vein-like structure is 0.95~1.05:1; the thickness of the ultra-wideband antireflective coating is no greater than 50μm; The leaf vein-like structure is composed of multi-level micro-nano lines with different widths and heights, wherein the height of the micro-nano lines is 0.5-20 μm and the width of the micro-nano lines is 0.5-20 μm.

2. The wear-resistant ultra-wideband anti-reflective film structure mimicking leaf veins according to claim 1, characterized in that, The material of the leaf vein-like structure includes one or more of epoxy resin, UV-curable adhesive, polydimethylsiloxane, tetrafluoroethylene, and transparent Teflon.

3. The wear-resistant ultra-wideband anti-reflective film structure mimicking leaf veins according to claim 1, characterized in that, The hardened layer is a nanolayer composed of high and low refractive index films in a specific ratio, and the film structure of the hardened layer is as follows: ,in, This represents a high-refractive-index film with a physical thickness of a nm. This represents a low-refractive-index film with a physical thickness of b nm, where x represents... and The number of floors; Among them, high refractive index film is a film with a refractive index of not less than 1.6, and low refractive index film is a film with a refractive index of not more than 1.

5.

4. The wear-resistant ultra-wideband anti-reflective film structure mimicking leaf veins according to claim 1, characterized in that, The ultra-wideband antireflective coating comprises a stacked film layer composed of high and low refractive index films and a porous ultra-low refractive index film located on the surface of the stacked film layer; the stacked film layer is composed of multiple high refractive index film layers and low refractive index film layers in a certain proportion, and the refractive index of the ultra-wideband antireflective coating is determined according to the target spectral range and the refractive index of the leaf vein-like structure; wherein the refractive index of the high refractive index film layer is not less than 2, the refractive index of the low refractive index film layer is not greater than 1.5, and the refractive index range of the porous ultra-low refractive index film is 1-1.

3.

5. The wear-resistant ultra-wideband anti-reflective film structure mimicking leaf veins according to claim 4, characterized in that, The film structure of the ultra-wideband antireflection film is as follows: ,in, This represents a high-refractive-index film with a physical thickness of c nm. This represents a low-refractive-index film with a physical thickness of d nm. This represents a porous ultra-low refractive index film with a physical thickness of e nm, where y represents... and The number of floors.

6. The wear-resistant ultra-wideband anti-reflective film structure mimicking leaf veins according to claim 4, characterized in that, The film structure of the ultra-wideband antireflection film is as follows: ,in, This represents a high-refractive-index film with a physical thickness of c nm. This represents a low-refractive-index film with a physical thickness of d nm. This represents a high-refractive-index film with a physical thickness of g nm. This represents a low-refractive-index film with a physical thickness of h nm. This represents a porous ultra-low refractive index film with a physical thickness of e nm.

7. The leaf vein-inspired wear-resistant ultrawide antireflective film structure according to any one of claims 1 to 6, characterized in that, The leaf vein-like structure includes a planar layer and surface protrusions, wherein the thickness of the planar layer is 20-500 μm.

8. The method for preparing the leaf vein-inspired wear-resistant ultrawide antireflective film structure according to any one of claims 1 to 7, characterized in that, Includes the following steps: S1: Prepare a leaf vein-like structure; the leaf vein-like structure is composed of multi-level micro-nano lines with different widths and heights, the height of the micro-nano lines is 0.5-20μm, and the width of the micro-nano lines is 0.5-20μm. S2: Prepare a hardened layer on the surface of the leaf vein-like structure; S3: Prepare an ultrawideband antireflection film on the surface of the hardened layer; Specifically, step S1, which involves preparing the leaf vein-like structure, includes the following steps: S11: Photolithography substrate with leaf vein-like structure fabricated using photolithography technology; S12: Using the leaf vein-like photolithography substrate obtained in step S11, prepare a leaf vein-like mold. S13: The leaf vein-like structure is prepared using nanoimprinting technology with the leaf vein-like structure mold.

9. The method for preparing the wear-resistant ultrawide antireflective film structure mimicking leaf veins according to claim 8, characterized in that, Step S3, which involves preparing an ultrawideband antireflective film on the surface of the hardened layer, specifically includes the following steps: S31: A stacked film layer composed of high and low refractive index films is prepared using atomic layer deposition technology; S32: Prepare an Al2O3 thin film on the outer layer of the stacked film layers; S33: The surface Al2O3 film is transformed into a grass-like alumina structure by using a hot water bath, and nanoscale thickness SiO2 or Al2O3 is prepared on the surface of the grass-like alumina structure by atomic layer deposition and then cured.

Images