A high-efficiency, wide-spectral-range light-absorbing metasurface and its preparation method

Abstract

This invention provides a high-efficiency, wide-spectral-range light-absorbing metasurface and its preparation method. The high-efficiency, wide-spectral-range light-absorbing metasurface comprises: a metasurface light-absorbing layer, including a plurality of arrayed light-absorbing units for absorbing light waves in the 400-2000 nanometer wavelength range; and a substrate disposed below the metasurface light-absorbing layer for supporting the metasurface light-absorbing layer. This invention provides a light-absorbing metasurface with a simple structure, capable of efficiently absorbing light waves over an extremely wide wavelength range, and exhibiting high stability and adaptability.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to a high-efficiency, wide-spectral-range light-absorbing metasurface and its preparation method. Background Technology

[0002] With the continuous development of optoelectronic technologies such as solar energy and photodetectors, the demand for high-efficiency, wide-spectral-range light-absorbing metasurfaces is increasing.

[0003] Existing light absorption technologies mainly rely on traditional light-absorbing materials, such as silicon-based materials or metallic materials. However, these materials typically have the following problems: First, their light absorption efficiency is limited, especially in the wide spectral range where they cannot effectively absorb light waves from the ultraviolet to the infrared bands. Second, most materials can only work effectively within a narrow spectral range, resulting in low light energy utilization efficiency. Third, most metasurfaces have relatively complex structures, which increases manufacturing costs.

[0004] Therefore, there is an urgent need to develop a new type of light-absorbing metasurface that is simple in structure, can efficiently absorb light waves over a wide wavelength range, and has high stability and adaptability. Summary of the Invention

[0005] To overcome the problems existing in related technologies, this invention provides a high-efficiency, wide-spectral-range light-absorbing metasurface and its preparation method.

[0006] According to a first aspect of the present invention, a high-efficiency, wide-spectral-range light-absorbing metasurface is provided, the high-efficiency, wide-spectral-range light-absorbing metasurface comprising:

[0007] The metasurface light-absorbing layer includes several arrayed light-absorbing units for absorbing light waves in the 400-2000 nanometer wavelength range;

[0008] A substrate is disposed below the metasurface light absorption layer to support the metasurface light absorption layer.

[0009] In some exemplary embodiments of the present invention, based on the foregoing scheme, the material of the metasurface light-absorbing layer is a three-dimensional topological insulator, including antimony telluride, bismuth telluride, bismuth selenide and mixtures thereof.

[0010] In some exemplary embodiments of the present invention, based on the foregoing scheme, the light absorption unit includes:

[0011] First light absorber.

[0012] The second light absorber is disposed adjacent to the first light absorber;

[0013] The first light absorber and the second light absorber are provided with a first groove, and the first light absorber and the second light absorber are axially symmetric about the center of the first groove, so that the first groove has a first isosceles triangular cross section.

[0014] In some exemplary embodiments of the present invention, based on the foregoing scheme, the height of the first isosceles triangular cross section is 160-260 nanometers and the length of the base is 120-200 nanometers.

[0015] In some exemplary embodiments of the present invention, based on the aforementioned scheme, a second groove is provided between two adjacent light-absorbing units, and the two adjacent light-absorbing units are axially symmetric about the center of the second groove, so that the second groove has a second isosceles triangular cross section.

[0016] In some exemplary embodiments of the present invention, based on the foregoing scheme, the height of the second isosceles triangular cross section is 300-400 nanometers and the length of the base is 200-280 nanometers.

[0017] In some exemplary embodiments of the present invention, based on the foregoing scheme, the light absorption unit and the second groove are formed as an array period, the array period being 660-740 nanometers.

[0018] In some exemplary embodiments of the present invention, based on the foregoing scheme, the distance between the vertex of the first isosceles triangle and the vertex of the second isosceles triangle is 300-400 nanometers.

[0019] In some exemplary embodiments of the present invention, based on the foregoing scheme, the substrate material is silicon dioxide, silicon, sapphire, or metal.

[0020] According to a second aspect of the present invention, a method for preparing a light-absorbing metasurface is provided, the method comprising:

[0021] The substrate is determined to be made of silicon dioxide, silicon, sapphire, or a metal.

[0022] Three-dimensional topological insulators of 1 micrometer size were deposited using magnetron sputtering or pulsed laser deposition techniques.

[0023] The light-absorbing units arranged in several arrays as described above are fabricated on the three-dimensional topological insulator using focused ion beam, laser processing, or electron beam lithography.

[0024] The technical solutions provided by the embodiments of the present invention may include the following beneficial effects:

[0025] This invention features a simple structure. Compared to existing technologies, the metasurface light-absorbing layer has fewer layers and employs an array structure, simplifying the design and manufacturing process, thereby reducing manufacturing costs and facilitating large-scale production and integration. Furthermore, the light-absorbing metasurface of this invention can absorb light waves in a broad spectral range of 400-2000 nanometers, covering the visible and near-infrared bands, exhibiting a wide spectral response capability and efficiently absorbing light of different wavelengths, making it suitable for various application scenarios. The presence of several arrayed light-absorbing units reduces reflection and scattering, effectively improving light absorption efficiency and achieving higher energy conversion efficiency. The substrate ensures that the light-absorbing layer stably supports and performs its optical properties, guaranteeing that the performance of the light-absorbing layer is not affected by external factors, while providing necessary support for the light-absorbing units, further enhancing the optical performance of the entire structure.

[0026] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit the invention. Attached Figure Description

[0027] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the specification, serve to explain the principles of the invention.

[0028] Figure 1 A schematic diagram illustrating the structure of a high-efficiency, wide-spectral-range light-absorbing metasurface according to some embodiments of the present invention is shown.

[0029] Figure 2 A schematic diagram illustrating a cross-sectional structure of a high-efficiency, wide-spectral-range light-absorbing metasurface according to some embodiments of the present invention is shown.

[0030] Figure 3 The diagram schematically illustrates the absorption spectrum of a metasurface with the following parameters: the absorption layer material is an antimony telluride thin film; the height h1 and base length a1 of the first isosceles triangular cross-section are 180 nm and 160 nm, respectively; the height h2 and base length a2 of the second isosceles triangular cross-section are 320 nm and 240 nm, respectively; the vertex distance b between the first and second isosceles triangular cross-sections is 350 nm; the array period p is 700 nm; and the overall thickness h3 of the metasurface is 1 μm.

[0031] Figure 4 The illustrations show changes according to some embodiments of the present invention. Figure 3 The absorption spectrum corresponding to the array period p, with other parameters remaining unchanged;

[0032] Figure 5 The illustrations show changes according to some embodiments of the present invention. Figure 3The absorption spectrum corresponding to the height h1 of the first isosceles triangle section, with other parameters remaining unchanged;

[0033] Figure 6 The illustrations show changes according to some embodiments of the present invention. Figure 3 The absorption spectrum corresponding to the height h2 of the second isosceles triangle section, with other parameters remaining unchanged;

[0034] Figure 7 A flowchart illustrating a method for preparing a light-absorbing metasurface according to some embodiments of the present invention is shown.

[0035] Explanation of reference numerals in the attached figures

[0036] 1. Substrate; 2. Metasurface light absorption layer; 21. Light absorption unit; 211. First light absorber; 212. Second light absorber; 213. First groove; 214. Second groove. Detailed Implementation

[0037] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided to make the invention more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore their detailed descriptions will be omitted.

[0038] The features, structures, or characteristics described above can be combined in any suitable manner in one or more embodiments, and the features discussed in the various embodiments are interchangeable where possible. In the above description, numerous specific details are provided to give a full understanding of embodiments of the invention. However, those skilled in the art will recognize that the technical solutions of the invention can be practiced without one or more of the specific details described, or other methods, components, materials, etc., can be employed. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring various aspects of the invention.

[0039] Although relative terms such as "up" and "down" are used in this invention to describe the relative relationship of one component of an icon to another, these terms are used only for convenience, such as according to the orientation of the examples shown in the accompanying drawings. It is understood that if the icon's arrangement is flipped so that it is upside down, the component described as "up" will become the component described as "down". Other relative terms such as "high", "low", "top", "bottom", "front", "back", "left", and "right" also have similar meanings. When a structure is "up" of another structure, it may mean that the structure is integrally formed on the other structure, or that the structure is "directly" mounted on the other structure, or that the structure is "indirectly" mounted on the other structure through another structure.

[0040] In this invention, the terms “a,” “an,” “the,” “the,” and “at least one” are used to indicate the presence of one or more elements / components / etc.; the terms “comprising,” “including,” and “having” are used to indicate an open-ended inclusion meaning and to mean that there may be other elements / components / etc. in addition to the listed elements / components / etc.

[0041] It should be understood that although the terms first, second, third, etc., may be used in this invention to describe various information, this information should not be limited to these terms. These terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of this invention, a first light absorber may also be referred to as a second light absorber, and similarly, a second light absorber may also be referred to as a first light absorber.

[0042] According to one aspect of the present invention, a high-efficiency, wide-spectral-range light-absorbing metasurface is provided, with reference to... Figure 1 As shown, the high-efficiency, wide-spectral-range light-absorbing metasurface includes:

[0043] The metasurface light absorption layer 2 includes several arrayed light absorption units 21 for absorbing light waves in the 400-2000 nanometer wavelength range;

[0044] Substrate 1 is disposed below the metasurface light absorption layer 2 and is used to support the metasurface light absorption layer 2.

[0045] In this embodiment of the invention, the light absorption unit 21 is capable of absorbing light waves in the 400-2000 nanometer wavelength range, which covers the range of visible and near-infrared light and has a wide spectral response capability. Each light absorption unit 21 in the array can optimize its absorption characteristics, thereby reducing light reflection or transmission losses, effectively improving light absorption efficiency, and thus maximizing energy conversion efficiency.

[0046] Substrate 1 is located below the metasurface light-absorbing layer 2 and mainly serves to support the light-absorbing layer. Substrate 1 is typically made of a suitable material to ensure the stability and structural integrity of the light-absorbing layer.

[0047] Silicon dioxide is a transparent material with high light transmittance, especially in the visible and near-infrared bands; it also has excellent chemical stability, allowing for long-term use under various environmental conditions without easily oxidizing or corroding; and it has relatively low cost. Therefore, in some embodiments, silicon dioxide can be used as the substrate material 1.

[0048] Silicon possesses excellent electrical conductivity and optical properties, particularly when combined with light-absorbing materials to improve photoelectron conversion efficiency. Furthermore, silicon processing technology is relatively mature, resulting in lower manufacturing difficulty and cost. It also exhibits good optical properties over a longer wavelength range (such as the near-infrared band), effectively absorbing and guiding light signals. Therefore, in some embodiments, silicon can be used as the substrate material.

[0049] Sapphire is an extremely hard material with excellent wear resistance and high heat resistance, which gives the sapphire substrate 1 good stability in high-temperature or harsh environments. Furthermore, sapphire has high light transmittance over a wide wavelength range. Therefore, in some embodiments, sapphire (aluminum oxide) can be used as the substrate material 1.

[0050] Metallic materials such as copper and aluminum possess excellent electrical and thermal conductivity, enabling the metal substrate 1 to effectively dissipate heat and conduct current. Furthermore, the metal surface exhibits strong light reflection characteristics, thus it can be used to enhance the optical properties of light-absorbing metasurfaces. Simultaneously, the metal substrate 1 is low in cost and easy to process. Therefore, in some embodiments, silicon metal can be used as the substrate material.

[0051] Three-dimensional topological insulators possess unique physical properties. While their interior is insulating, their surface exhibits stable electronic states, known as topological surface states. These surface states are insensitive to external disturbances, can efficiently transport charge on the surface, and possess excellent electrical and optical properties. The surface states of topological insulators can enhance their interaction with light, resulting in high efficiency in applications such as light absorption and photoelectric conversion. Particularly across a wide spectral range, topological insulators can absorb more light waves, improving light absorption efficiency. Therefore, in some embodiments, three-dimensional topological insulators can be used as the material for the metasurface light-absorbing layer 2.

[0052] Antimony telluride is a typical topological insulator material with a narrow band gap, making it suitable for effective light absorption in the ultraviolet to infrared band. It exhibits good photoelectric properties over a wide wavelength range, and possesses good thermal stability and oxidation resistance, maintaining good performance even at high temperatures, thus making it suitable for high-temperature applications.

[0053] Bismuth telluride is a widely studied topological insulator material with high carrier mobility and excellent electronic properties, and it can effectively absorb infrared light and some visible light.

[0054] Bismuth selenide possesses very stable surface states, which can effectively improve light absorption, especially in the ultraviolet to near-infrared light absorption band, and has a wide spectral response range.

[0055] By combining antimony telluride, bismuth telluride, and bismuth selenide, the advantages of each can be combined to optimize the optical, electronic, and thermal properties of the material, thereby enhancing light absorption at different wavelengths and providing more efficient photoelectric conversion.

[0056] Therefore, antimony telluride, bismuth telluride, bismuth selenide, and mixtures thereof can be used as the material for the metasurface light absorption layer 2.

[0057] This invention does not impose specific limitations on the structure of the light absorption unit 21.

[0058] In an embodiment of the present invention, the light absorption unit 21 may include

[0059] First light absorber 211,

[0060] The second light absorber 212 is disposed adjacent to the first light absorber 211;

[0061] A first groove 213 is formed between the first light absorber 211 and the second light absorber 212. The first light absorber 211 and the second light absorber 212 are axially symmetric about the center of the first groove 213, so that the first groove 213 has a first isosceles triangular cross-section. A second groove 214 is designed between adjacent light absorber units 21, and the second groove 214 has a second isosceles triangular cross-section. In this way, by placing the first light absorber 211 and the second light absorber 212 adjacent to each other, an array of first grooves 213 and an array of second grooves 214 are formed through their close positional fit.

[0062] The first groove array 213 and the second groove array 214 can each be considered as a two-dimensional grating structure, wherein: the first groove array 213 is a two-dimensional grating with a period of p and cross-sectional height and base length of h1 and a1, respectively; the second groove array 214 is a two-dimensional grating with a period of p and cross-sectional height and base length of h2 and a2, respectively. The two two-dimensional gratings form resonant modes with different resonant wavelengths within the first groove 213 and the second groove 214, respectively, capable of absorbing incident light waves within corresponding wavelength ranges. In this invention, both the first groove 213 and the second groove 214 are designed with isosceles triangular cross-sections, which can widen their resonant valleys, thereby increasing the wavelength range of light absorption and improving the light absorption performance of the metasurface.

[0063] The height h1 and base length a1 of the first groove 213 array are 180 nm and 160 nm, respectively, with a resonant wavelength in the visible light band and a relatively wide resonant valley. In this embodiment of the invention, the height h1 of the first isosceles triangular cross-section is designed to be 160-260 nm. Further, it can be 160 nm, 180 nm, 200 nm, 220 nm, 240 nm, 260 nm, etc. Within this height range, the resonant wavelength of the first groove 213 array can be controlled near the visible light band. The base length a1 of the first isosceles triangular cross-section can, for example, be 120 nm-200 nm. Further, it can be 120 nm, 140 nm, 160 nm, 180 nm, 200 nm, etc., and this design range is thus adapted to the height h1 of the cross-section.

[0064] The height h2 and base length a2 of the second groove 214 array are 320 nm and 240 nm, respectively. Unlike the height h1 of the first isosceles triangular cross-section, the height h2 of the second isosceles triangular cross-section is increased, resulting in a resonant wavelength of the second groove 214 array in the near-infrared band, and a relatively wide resonance valley. In this embodiment of the invention, the height h2 of the second isosceles triangular cross-section is 300-400 nm. Further, it can be 300 nm, 320 nm, 340 nm, 360 nm, 380 nm, 400 nm, etc. Within this height range, the resonant wavelength of the second groove 214 array can be controlled near the near-infrared band. The base length a2 of the second isosceles triangular cross-section is designed to be 200-280 nm. Further, it can be 200 nm, 220 nm, 240 nm, 260 nm, 280 nm, etc., and this design range is thus adapted to the height h2 of the cross-section.

[0065] The resonant wavelengths of the first groove array 213 and the second groove array 214 are near the visible and near-infrared bands, respectively, and can absorb incident light waves in the corresponding bands. The light absorption unit array 21 can be regarded as a superposition of the first groove array 213 and the second groove array 214, and their light absorption performance can also be superimposed, thereby expanding the light absorption wavelength range. At the same time, the first groove array 213 and the second groove array 214 together form an array of near-two-dimensional gratings with a period of b, whose theoretical resonant wavelength is shorter than that of the first groove array 213 and the second groove array 214, which can further expand the light absorption wavelength range.

[0066] The array period p refers to the spacing between adjacent light-absorbing units 21, and is also the period of the first groove 213 array and the second groove 214 array, determining the geometric characteristics and optical response of the metasurface. Designing a suitable array period p to match the wavelength of light can excite a resonance effect, allowing the incident light to be effectively localized and absorbed due to optical resonance, thus improving light absorption efficiency. Therefore, in some embodiments, the array period can be designed to be 660-740 nanometers. Within this distance range, the first groove 213 array and the second groove 214 array can resonate at different resonance wavelengths. This resonance can enhance light absorption, especially in the ultraviolet to infrared band, improving the broad spectral response of the light-absorbing metasurface. Further, it can be 660 nanometers, 680 nanometers, 700 nanometers, 720 nanometers, 740 nanometers, etc., to adapt to different light sources and wavelengths while ensuring that the absorption efficiency of the metasurface is maximized in a specific wavelength band.

[0067] The vertex distance *b* between the first and second isosceles triangular sections defines the spatial relationship between two adjacent light-absorbing units 21, particularly the accuracy of their relative positions in the array. By setting an appropriate vertex distance, the light absorption efficiency can be improved. Therefore, the vertex distance *b* between the first and second isosceles triangles can be precisely set to optimize the resonant wavelength of the metasurface, increase the interaction between light and the absorbing material, and further improve the light absorption efficiency.

[0068] In some embodiments of the present invention, the distance b between the vertices of the first isosceles triangle and the second isosceles triangle is designed to be 300-400 nanometers. Further, it can be 300 nanometers, 320 nanometers, 340 nanometers, 360 nanometers, 380 nanometers, 400 nanometers, etc. Within this distance range, the two-dimensional grating array composed of the first groove 213 array and the second groove 214 array can form a resonance effect at short wavelengths, which can further expand the wavelength range of metasurface light absorption and improve the light absorption performance of metasurface.

[0069] Furthermore, the height h3 of the metasurface light absorption layer 2 can be designed to be 1-1.5 micrometers. This height range, within the micrometer level, can effectively increase the "thickness" of the absorption layer, thereby allowing light to travel a longer distance within the light absorption layer and ensuring the stability of the metasurface light absorption layer 2. At the same time, it should not be too high, leading to increased structural complexity and material usage. Further, it can be 1 micrometer, 1.1 micrometer, 1.2 micrometer, 1.3 micrometer, 1.4 micrometer, 1.5 micrometer, etc.

[0070] Figure 3 When the absorber layer material is an antimony telluride thin film, the height h1 and base length a1 of the first isosceles triangular cross-section are selected to be 180 nm and 160 nm, respectively; the height h2 and base length a2 of the second isosceles triangular cross-section are 320 nm and 240 nm, respectively; the vertex distance b between the first and second isosceles triangular cross-sections is 350 nm; the array period p is 700 nm; and the overall metasurface thickness h3 is 1 μm. The resulting absorption spectrum of the metasurface achieves an average light absorption of 93.8% in the 400-2000 nm wavelength range, with a maximum absorption rate of 99% at 704 nm. Based on these structural parameters, by changing the array period p, the height h1 of the second isosceles triangular cross-section, and the height h2 of the first isosceles triangular cross-section, absorption spectra of metasurfaces with different parameters can be obtained, such as... Figures 4-6 As shown.

[0071] Based on this, this invention achieves highly efficient light absorption across a wide wavelength range of 400-2000 nanometers using only a 1-1.5 micrometer single-layer structure, covering the entire visible light spectrum and part of the near-infrared band, regardless of the polarization of the incident light. The average light absorption rate reaches 93.8% in the 400-2000 nanometer band, with a maximum absorption rate of 99%. This structure overcomes the shortcomings of existing multilayer light-absorbing structures, such as low absorption efficiency and narrow operating wavelengths, and is easily integrated with objects or other optical components. Furthermore, the fabrication process of this structure is relatively simple and highly practical. This invention provides a new solution for achieving highly efficient light absorption across a wide visible-near-infrared band, and has significant application prospects in light absorbers, solar cells, optical stealth, photothermal conversion, and photoelectric detection.

[0072] According to a second aspect of the embodiments of the present invention, reference is made to Figure 7 As shown, a method for preparing a light-absorbing metasurface is provided, the method comprising:

[0073] S710: Substrate 1, which is made of silicon dioxide, silicon, sapphire, or metal;

[0074] S720: A 1-micron three-dimensional topological insulator is deposited using magnetron sputtering or pulsed laser deposition technology;

[0075] S730: Light-absorbing units 21 arranged in several arrays as described above are fabricated on the three-dimensional topological insulator using focused ion beam, laser processing, or electron beam lithography.

[0076] In S710, a substrate 1 is defined as being made of silicon dioxide, silicon, sapphire, or a metal.

[0077] Here, different substrate materials 1 will have different effects on the optical properties of the light-absorbing metasurface. For example, silicon dioxide substrate 1 is suitable for applications requiring transparency, silicon substrate 1 is more suitable for integrated circuits or optoelectronic devices, while metal substrate 1 can effectively increase reflection and heat dissipation performance. The choice of different substrate materials 1 provides different application scenarios for the light-absorbing metasurface, which can meet diverse needs from low cost to high performance, from high temperature to high power, and those skilled in the art can determine the appropriate application based on the actual situation.

[0078] In the S720, a 1-micron three-dimensional topological insulator is deposited using magnetron sputtering or pulsed laser deposition techniques.

[0079] Magnetron sputtering (MS) is a physical vapor deposition technique that ionizes a gas in a vacuum environment and then accelerates these ions to bombard a target, exciting the sputtering of material from the target surface. These sputtered particles then deposit onto a substrate to form a thin film. Magnetron sputtering can uniformly deposit thin films on large-area substrates, making it particularly suitable for large-scale production. Furthermore, by adjusting the sputtering time, power, and gas flow rate, the thickness of the deposited film can be precisely controlled, making it ideal for light-absorbing layers requiring specific thicknesses (e.g., 1 micrometer). In addition, sputtering technology can deposit high-quality thin films, particularly suitable for surface modification and multilayer film fabrication. It can form dense films at relatively low temperatures, contributing to improved performance of three-dimensional topological insulators.

[0080] Pulsed Laser Deposition (PLD) uses high-energy laser pulses to irradiate a target. After absorbing the laser energy, some of the material is excited, evaporates, and condenses onto the substrate, forming a thin film. The high energy density of the laser allows the material to evaporate and be deposited onto the substrate surface with high quality. PLD technology can achieve very high film quality, and is particularly suitable for preparing high-purity films with good crystal structures, making it suitable for fabricating demanding optoelectronic materials such as three-dimensional topological insulators. Furthermore, it allows for precise control of the deposition thickness in a short time, ensuring the uniformity and consistency of the deposited layer, especially when very high film thickness requirements are needed. It is suitable for depositing three-dimensional topological insulators with a thickness of 1 micrometer.

[0081] Three-dimensional topological insulators, such as antimony telluride (Sb₂Te₃), bismuth telluride (Bi₂Te₃), and bismuth selenide (Bi₂Se₃), possess unique topological surface states and insulating states, which help improve the performance of light-absorbing metasurfaces. These materials can be uniformly and precisely deposited onto substrates using magnetron sputtering or pulsed laser deposition techniques to form a 1-micrometer-thick three-dimensional topological insulator layer. Magnetron sputtering is suitable for large-area deposition and cost control, while pulsed laser deposition offers higher film quality and finer thickness control. Those skilled in the art can choose the appropriate technique based on specific practical needs (such as film quality, deposition area, and cost control).

[0082] In S730, light-absorbing units 21 arranged in several arrays as described above are fabricated on the three-dimensional topological insulator using focused ion beam, laser processing, or electron beam lithography.

[0083] Focused ion beam (FIB) technology utilizes high-energy ion beams to precisely sculpt and process material surfaces. Ion beams possess high energy density, enabling the cutting, deposition, and modification of materials at the nanoscale. This provides extremely high processing precision, making it suitable for fabricating nanoscale light-absorbing units 21. It not only precisely controls structural dimensions, ensuring the geometry of each light-absorbing unit 21 meets design requirements, but also allows for fine processing of localized areas of the material, eliminating the need for batch processing of the entire material. This makes it suitable for fabricating complex arrays of light-absorbing units 21 on the surface of three-dimensional topological insulators.

[0084] Laser processing technology uses a high-intensity laser beam to heat the surface of a material, causing it to melt or vaporize in the laser-irradiated area, thereby achieving cutting, engraving, and surface modification. Laser processing allows for precise control of the laser energy, pulse width, and irradiation time to adjust the processing effect. Furthermore, laser processing is non-contact, reducing the impact of mechanical stress on the material and avoiding material deformation or damage that may occur in traditional machining, making it suitable for the processing of precision micro- and nano-structures. In addition, laser processing technology typically offers high processing speeds, making it suitable for rapidly fabricating light-absorbing unit arrays on large-area substrates.

[0085] Electron beam lithography utilizes a focused electron beam to irradiate a substrate coated with a photosensitive material (such as polymethyl methacrylate, PMMA). The radiation from the electron beam alters the chemical properties of the photosensitive material, forming micro- and nano-scale structures through a development process. Electron beam lithography can precisely etch desired patterns onto material surfaces or thin films by adjusting the electron beam energy, scanning speed, and exposure time. It offers extremely high spatial resolution, typically reaching the nanometer scale, making it suitable for fabricating complex and high-precision light-absorbing units. Furthermore, it possesses high flexibility, capable of handling various materials, and allows for precise adjustment of the shape and size of the lithographic pattern to meet the manufacturing needs of complex structures.

[0086] Whether it's focused ion beam, laser processing, or electron beam lithography, all can achieve nanoscale precision processing on the surface of a three-dimensional topological insulator. Therefore, those skilled in the art can choose an appropriate method to fabricate the arrayed light-absorbing units 21 described above on the three-dimensional topological insulator, and this invention does not impose any specific limitations.

[0087] Other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. The invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of the invention are indicated by the claims.

[0088] It should be understood that the present invention is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A high-efficiency, wide-spectral-range light-absorbing metasurface, characterized in that, include: The metasurface light-absorbing layer includes several arrayed light-absorbing units for absorbing light waves in the 400-2000 nanometer wavelength range; A substrate is disposed below the metasurface light absorption layer to support the metasurface light absorption layer; The light absorption unit includes: First light absorber. The second light absorber is disposed adjacent to the first light absorber; The first light absorber and the second light absorber are provided with a first groove, and the first light absorber and the second light absorber are axially symmetric about the center of the first groove, so that the first groove has a first isosceles triangular cross section; a second groove is provided between two adjacent light absorber units, and the two adjacent light absorber units are axially symmetric about the center of the second groove, so that the second groove has a second isosceles triangular cross section.

2. The high-efficiency, wide-spectral-range light-absorbing metasurface according to claim 1, characterized in that, The material of the metasurface light-absorbing layer is a three-dimensional topological insulator, including antimony telluride, bismuth telluride, bismuth selenide, and mixtures thereof.

3. The high-efficiency, wide-spectral-range light-absorbing metasurface according to claim 1, characterized in that, The height of the first isosceles triangular cross section is 160-260 nanometers, and the length of the base is 120-200 nanometers.

4. The high-efficiency, wide-spectral-range light-absorbing metasurface according to claim 1, characterized in that, The height of the second isosceles triangular cross section is 300-400 nanometers, and the length of the base is 200-280 nanometers.

5. The high-efficiency, wide-spectral-range light-absorbing metasurface according to claim 1, characterized in that, The light-absorbing unit and the second groove are formed in an array period of 660-740 nanometers.

6. The high-efficiency, wide-spectral-range light-absorbing metasurface according to claim 1, characterized in that, The distance between the vertex of the first isosceles triangle and the vertex of the second isosceles triangle is 300-400 nanometers.

7. The high-efficiency, wide-spectral-range light-absorbing metasurface according to any one of claims 1-6, characterized in that, The substrate is made of silicon dioxide, silicon, sapphire, or metal.

8. A method for preparing a light-absorbing metasurface, characterized in that, The method for preparing the optically absorbing metasurface includes: The substrate is determined to be made of silicon dioxide, silicon, sapphire, or a metal. Three-dimensional topological insulators of 1 micrometer size were deposited using magnetron sputtering or pulsed laser deposition techniques. A plurality of arrayed light-absorbing units as described in any one of claims 1-7 are fabricated on the three-dimensional topological insulator using focused ion beam, laser processing, or electron beam lithography.

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