Light absorption metasurface with high efficiency and wide spectral range and preparation method thereof

Abstract

The invention provides a light absorption metasurface with high efficiency and a wide spectral range and a preparation method thereof, and the metasurface comprises a metasurface light absorption layer which comprises a plurality of light absorption units arranged in an array and is used for absorbing light waves in the wave band of 400-2000 nanometers; and the substrate is arranged below the metasurface light absorption layer and is used for supporting the metasurface light absorption layer. The light absorption metasurface is simple in structure, can efficiently absorb light waves in an extremely wide wavelength range, and has high stability and adaptability.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a high-efficiency, wide-spectrum light-absorbing metasurface and a preparation method thereof. Background Art

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

[0003] Existing light absorption technology mainly relies on traditional light absorption materials, such as silicon-based materials or metal materials, but these materials usually have the following problems: First, the light absorption efficiency is limited, especially in the wide spectral range, the light waves from ultraviolet to infrared bands cannot be effectively absorbed; second, most materials can only work effectively within a narrow spectral range, resulting in low efficiency of light energy utilization; third, most metasurfaces have a relatively complex structure, which invisibly increases the manufacturing cost.

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

[0005] In order to overcome the problems existing in the related art, the present invention provides a light-absorbing metasurface with high efficiency and wide spectral range and a preparation method thereof.

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

[0007] The metasurface light absorption layer includes a plurality of light absorption units arranged in an array, and is used to absorb light waves in the 400-2000 nanometer band;

[0008] A substrate is arranged below the supersurface light absorbing layer and is used to support the supersurface light absorbing layer.

[0009] In some example embodiments of the present invention, based on the aforementioned scheme, the material of the metasurface light absorption 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 above solution, the light absorption unit includes:

[0011] a first light absorber,

[0012] a second light absorber, disposed adjacent to the first light absorber;

[0013] There is a first groove between the first light absorber and the second light absorber, and the first light absorber and the second light absorber are in an axisymmetric structure about the center of the first groove, so that the first groove has a first isosceles triangle cross-section.

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

[0015] In some example embodiments of the present invention, based on the above solution, a second groove is provided between two adjacent light absorbing units, and the two adjacent light absorbing units are axially symmetrical about the center of the second groove, so that the second groove has a second isosceles triangle cross-section.

[0016] In some exemplary embodiments of the present invention, based on the above solution, the height of the second isosceles triangle 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 above solution, the light absorption unit and the second groove are formed into an array period, and the array period is 660-740 nanometers.

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

[0019] In some example embodiments of the present invention, based on the above-mentioned solution, the material of the substrate is silicon dioxide, silicon, sapphire or metal.

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

[0021] Determine the substrate material to be silicon dioxide, silicon, sapphire or metal;

[0022] Using magnetron sputtering or pulsed laser deposition technology to deposit 1 micron three-dimensional topological insulators;

[0023] A plurality of light absorption units arranged in an array as described above are prepared on the three-dimensional topological insulator using focused ion beam, laser processing or electron beam lithography technology.

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

[0025] The present invention has a simple structure, and the metasurface light absorption layer has fewer layers than the prior art and adopts an array structure, which can simplify the design and manufacturing process, thereby reducing manufacturing costs and facilitating large-scale production and integration. The light-absorbing metasurface of the present invention can absorb light waves in a wide spectral range of 400-2000 nanometers, covering visible light and near-infrared bands, has a wide spectral response capability, can efficiently absorb light of different wavelengths, and is suitable for a variety of application scenarios. The presence of several light absorption units arranged in an array can reduce reflection and scattering, thereby effectively improving the absorption efficiency of light, thereby achieving higher energy conversion efficiency. The setting of the substrate enables the light absorption layer to stably carry and exert its optical properties, ensuring that the performance of the light absorption layer is not interfered with by external factors, while providing necessary support for the light absorption unit, further improving the optical efficiency of the entire structure.

[0026] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0028] Figure 1 Schematically showing a schematic diagram of the structure of a high-efficiency, wide-spectral-range light-absorbing metasurface according to some embodiments of the present invention;

[0029] Figure 2 Schematically showing a cross-sectional structure diagram of a light-absorbing metasurface with high efficiency and wide spectral range according to some embodiments of the present invention;

[0030] Figure 3 Schematically showing the structural parameters of the metasurface: the absorption layer material is antimony telluride film, the height h1 and the base length a1 of the first isosceles triangle section are 180 nanometers and 160 nanometers respectively, the height h2 and the base length a2 of the second isosceles triangle section are 320 nanometers and 240 nanometers respectively, the vertex distance b between the first isosceles triangle section and the second isosceles triangle section is 350 nanometers, and the array period p is 700 nanometers; the absorption spectrum corresponding to the overall thickness h3 of the metasurface is 1 micrometer;

[0031] Figure 4 Schematically illustrates the changes of some embodiments according to the present invention Figure 3 The absorption spectrum corresponding to the array period p and other parameters remain unchanged;

[0032] Figure 5 Schematically illustrates the changes of some embodiments according to the present invention Figure 3The height h1 of the first isosceles triangle cross section, and the corresponding absorption spectrum when other parameters remain unchanged;

[0033] Figure 6 Schematically illustrates the changes of some embodiments according to the present invention Figure 3 The height h2 of the second isosceles triangle section, and the corresponding absorption spectrum when other parameters remain unchanged;

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

[0035] Description of Reference Numerals

[0036] 1. Substrate; 2. Supersurface light absorption layer; 21. Light absorption unit; 211. First light absorber; 212. Second light absorber; 213. First groove; 214. Second groove. DETAILED DESCRIPTION

[0037] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided to make the present invention more comprehensive and complete and to fully convey the concepts of the example embodiments to those skilled in the art. The same reference numerals in the figures represent the same or similar structures, and thus their detailed description will be omitted.

[0038] The features, structures or characteristics described above may be combined in one or more embodiments in any suitable manner, and if possible, the features discussed in each embodiment are interchangeable. In the above description, many specific details are provided to provide a full understanding of the embodiments of the present invention. However, those skilled in the art will appreciate that the technical solution of the present invention may be practiced without one or more of the specific details, or other methods, components, materials, etc. may be adopted. In other cases, known structures, materials or operations are not shown or described in detail to avoid blurring various aspects of the present invention.

[0039] Although relative terms such as "upper" and "lower" are used in the present invention to describe the relative relationship of one component of the illustration to another component, these terms are used in the present invention only for convenience, such as the orientation of the examples described in the drawings. It is understood that if the device of the illustration is turned over and turned upside down, the component described as being "upper" will become the component "lower". Other relative terms such as "high", "low", "top", "bottom", "front", "back", "left", "right", etc. are also used to have similar meanings. When a structure is "on" other structures, it may mean that the structure is formed integrally on the other structure, or that the structure is "directly" disposed on the other structure, or that the structure is "indirectly" disposed on the other structure through another structure.

[0040] In the present invention, the terms "a", "an", "the", "said" 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 express an open-ended inclusion and mean that additional elements / components / etc. may exist 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 the present invention to describe various information, such information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present invention, the first light absorber may also be referred to as the second light absorber, and similarly, the second light absorber may also be referred to as the first light absorber.

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

[0043] The metasurface light absorption layer 2 includes a plurality of light absorption units 21 arranged in an array, and is used to absorb light waves in the 400-2000 nanometer band;

[0044] The substrate 1 is arranged below the supersurface light absorbing layer 2 and is used to support the supersurface light absorbing layer 2.

[0045] In the embodiment of the present invention, the light absorption unit 21 can absorb light waves in the 400-2000 nanometer band, which covers the range of visible light and near-infrared light and has a wide spectrum response capability. Each light absorption unit 21 in the array can optimize the absorption characteristics, thereby reducing the loss of light reflection or transmission, effectively improving the light absorption efficiency, and thus maximizing the energy conversion efficiency.

[0046] The substrate 1 is located below the metasurface light absorbing layer 2 and mainly plays the role of supporting the light absorbing layer. The substrate 1 is usually made of a suitable material to ensure the stability and structural integrity of the light absorbing layer.

[0047] Since silicon dioxide is a transparent material with high light transmittance, especially in the visible light and near infrared bands, and has excellent chemical stability, it can be used for a long time under various environmental conditions without being easily oxidized or corroded, and has a relatively low cost, in some embodiments, silicon dioxide can be used as the substrate 1 material.

[0048] Since silicon has good electrical conductivity and optical properties, especially when combined with light absorbing materials, it can improve the efficiency of photoelectron conversion; and the processing technology of silicon materials is relatively mature, with low manufacturing difficulty and cost; and it has good optical properties in a longer wavelength range (such as the near-infrared band), and can effectively absorb and guide light signals. Therefore, in some embodiments, silicon can be used as the material of the substrate 1.

[0049] Sapphire is a very hard material with excellent wear resistance and high heat resistance, which makes the sapphire substrate 1 show good stability under high temperature or harsh environment, and sapphire has high light transmittance in a wide band. Therefore, in some embodiments, sapphire (aluminum oxide) can be used as the substrate 1 material.

[0050] Metal materials such as copper and aluminum have excellent electrical and thermal conductivity, which enables the metal substrate 1 to effectively dissipate heat and conduct current, and the metal surface has strong light reflection characteristics, so it can be used to enhance the optical properties of the light absorbing metasurface. At the same time, the metal substrate 1 has low cost and is easy to process. Therefore, in some embodiments, silicon metal can be used as the substrate 1 material.

[0051] Three-dimensional topological insulators have unique physical properties. They are insulating inside, but there is a stable electronic state on the surface, called topological surface states. These surface states are insensitive to external disturbances, can effectively transfer charges on the surface, and have excellent electrical and optical properties. The surface states of topological insulators can enhance the interaction with light, which makes them show efficient performance in applications such as light absorption and photoelectric conversion. Especially in a wide spectral range, topological insulators can absorb more light waves and improve light absorption efficiency. Therefore, in some embodiments, three-dimensional topological insulators can be used as the material of the supersurface light absorption layer 2.

[0052] Antimony telluride is a typical topological insulator material with a narrow energy band gap, suitable for efficient light absorption in the ultraviolet to infrared band. It can exhibit good optoelectronic properties in a wide wavelength range, and has good thermal stability and oxidation resistance, and can maintain good performance in high temperature environments, so it is suitable for high temperature applications.

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

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

[0055] By mixing antimony telluride, bismuth telluride and bismuth selenide, we can combine the advantages of each and optimize the optical, electronic and thermal properties of the material to enhance light absorption in different bands and provide more efficient photoelectric conversion efficiency.

[0056] Therefore, one of antimony telluride, bismuth telluride, bismuth selenide and a mixture thereof can be used as the material of the supersurface light absorption layer 2 .

[0057] The present invention does not impose any specific restrictions on the structure of the light absorbing unit 21.

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

[0059] The first light absorber 211,

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

[0061] There is a first groove 213 between the first light absorber 211 and the second light absorber 212, and the first light absorber 211 and the second light absorber 212 are axially symmetrical about the center of the first groove 213, so that the first groove 213 has a first isosceles triangle cross section. The second groove 214 is designed to be located between adjacent light absorbing units 21, and the second groove 214 has a second isosceles triangle cross section. In this way, by placing the first light absorber 211 and the second light absorber 212 adjacent to each other, a first groove 213 array and a second groove 214 array are formed through close fit in position.

[0062] The first groove 213 array and the second groove 214 array can be respectively regarded as two-dimensional grating structures, wherein: the first groove 213 array is a two-dimensional grating with a period of p, a cross-sectional height and a bottom length of h1 and a1; the second groove 214 array is a two-dimensional grating with a period of p, a cross-sectional height and a bottom length of h2 and a2. The two two-dimensional gratings form resonance modes with different resonance wavelengths in the first groove 213 and the second groove 214, respectively, and can absorb incident light waves in the corresponding wavelength range. In the present invention, the first groove 213 and the second groove 214 are both designed as isosceles triangle cross-sections, which can widen their resonance valleys, thereby increasing the wavelength range of light absorption and improving the light absorption performance of the metasurface.

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

[0064] The second groove 214 array height h2 and the base length a2 are 320 nanometers and 240 nanometers respectively. Different from the height h1 of the first isosceles triangle cross section, the height h2 of the second isosceles triangle cross section is increased, so that the second groove 214 array resonant wavelength is in the near-infrared band, and the resonance valley is also wide. In the implementation of the present invention, the height h2 of the second isosceles triangle cross section is 300-400 nanometers. Further, it can be 300 nanometers, 320 nanometers, 340 nanometers, 360 nanometers, 380 nanometers, 400 nanometers, 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 triangle cross section is designed to be 200-280 nanometers. Further, it can be 200 nanometers, 220 nanometers, 240 nanometers, 260 nanometers, 280 nanometers, etc., and this design range is thus adapted to the height h2 of the cross section.

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

[0066] The array period p refers to the spacing between adjacent light absorption units 21, and is also the period of the first groove 213 array and the second groove 214 array, which determines the geometric characteristics of the metasurface and its optical response. Designing a suitable array period p to match the wavelength of light can stimulate the resonance effect, so that the incident light is effectively localized and absorbed due to optical resonance, thereby improving the light absorption efficiency. Therefore, in some embodiments, the array period can be designed to be 660-740 nanometers. Within this distance range, the resonance formed by the first groove 213 array and the second groove 214 array at different resonance wavelengths can enhance the light absorption capacity, especially the light absorption in the ultraviolet to infrared band, and enhance the wide spectrum response capability of the light absorption metasurface. Further, it can be 660 nanometers, 680 nanometers, 700 nanometers, 720 nanometers, 740, etc., so as to adapt to the changes of different light sources and wavelengths while ensuring that the absorption efficiency of the metasurface is maximized in a specific band.

[0067] The vertex distance b between the first isosceles triangle section and the second isosceles triangle section defines the spatial relationship between two adjacent light absorption units 21, especially the accuracy of their relative positions in the array. By setting an appropriate vertex distance, the light absorption efficiency is improved. Therefore, the vertex distance b between the first isosceles triangle and the second isosceles triangle can be accurately set to optimize the resonant wavelength of the metasurface, increase the interaction between light and the absorption material, and further improve the light absorption efficiency.

[0068] In some embodiments of the present invention, the vertex distance b between the first isosceles triangle and the second isosceles triangle is designed to be 300-400 nanometers, and further, 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 a short wavelength, which can further expand the wavelength range of metasurface light absorption and improve the light absorption performance of the metasurface.

[0069] In addition, the height h3 of the supersurface light absorption layer 2 can be designed to be 1-1.5 microns. This height range is in the micron level, which can effectively increase the "thickness" of the absorption layer, thereby making the light propagate a longer distance in the light absorption layer, ensuring the stability of the supersurface light absorption layer 2, while not being too high, resulting in increased structural complexity and material usage. Further, it can be 1 micron, 1.1 microns, 1.2 microns, 1.3 microns, 1.4 microns, 1.5 microns, etc.

[0070] Figure 3 When the absorption layer material is antimony telluride film, the height h1 and base length a1 of the first isosceles triangle section are selected to be 180 nanometers and 160 nanometers respectively; the height h2 and base length a2 of the second isosceles triangle section are selected to be 320 nanometers and 240 nanometers respectively; the vertex distance b between the first isosceles triangle section and the second isosceles triangle section is 350 nanometers; the array period p is 700 nanometers; the absorption spectrum of the light absorption metasurface corresponding to the overall thickness h3 of the metasurface of 1 micron achieves an average light absorption of 93.8% in the 400-2000 nanometer band, and the maximum light absorption rate is 99% at 704 nanometers. Based on these structural parameters, the array period p, the height h1 of the second isosceles triangle section, and the height h2 of the first isosceles triangle section are changed respectively, and the absorption spectra of the metasurface with different parameters can be obtained, such as Figure 4-Figure 6 shown.

[0071] Based on this, the present invention achieves efficient light absorption in a wide band of 400-2000 nanometers with only a 1-1.5 micron single-layer structure, covering the entire visible light and part of the near-infrared band, regardless of the polarization of the incident light. The average light absorption rate in the 400-2000 nanometer band reaches 93.8%, and the maximum light absorption rate is 99%. This structure can overcome the shortcomings of the existing light absorption multilayer structure, which has low absorption efficiency and narrow working band, and is easy to integrate with objects or other optical components. In addition, the preparation process of this structure is relatively simple and has strong practicality. The present invention provides a new solution for achieving efficient light absorption in a wide band of visible light and near-infrared, and has important application prospects in light absorbers, solar cells, optical stealth, photothermal conversion, photoelectric detection, etc.

[0072] According to a second aspect of the embodiment of the present invention, referring to Figure 7 As shown, a method for preparing a light-absorbing metasurface is provided, and the method for preparing the light-absorbing metasurface comprises:

[0073] S710: Determine a substrate 1 whose material is silicon dioxide, silicon, sapphire or metal;

[0074] S720: Fabrication of 1-micron 3D topological insulators using magnetron sputtering or pulsed laser deposition techniques;

[0075] S730: using focused ion beam, laser processing or electron beam lithography technology to prepare a plurality of light absorption units 21 arranged in an array as described above on the three-dimensional topological insulator.

[0076] In S710 , a substrate 1 is determined to be made of silicon dioxide, silicon, sapphire or metal.

[0077] Here, substrates 1 of different materials 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, and metal substrate 1 can effectively increase reflection and heat dissipation performance. The selection of different substrate 1 materials provides different application scenarios for light-absorbing metasurfaces, which can meet diverse needs from low cost to high performance, from high temperature to high power, and can be determined by technicians in this field according to actual conditions.

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

[0079] Magnetron sputtering (MS) is a physical vapor deposition technology that ionizes gas in a vacuum environment and then accelerates these ions to hit the target material, which stimulates the surface material of the target material to sputter out. These sputtered particles will be deposited on the substrate to form a thin film. Magnetron sputtering can deposit thin films uniformly on large-area substrates, which is particularly suitable for large-scale production. And by adjusting the sputtering time, power and gas flow, the thickness of the deposited film can be precisely controlled, which is very suitable for light absorption layers that require a specific thickness (such as 1 micron). In addition, sputtering technology can deposit high-quality thin films, which is particularly suitable for surface modification of materials and the preparation of multilayer films. It can form dense films at lower temperatures, which helps to improve the performance of three-dimensional topological insulators.

[0080] Pulsed Laser Deposition (PLD) uses high-energy laser pulses to irradiate the target material. After the target material absorbs the laser energy, part of the material is excited, evaporated and condensed onto the substrate to form a thin film. The high energy density of the laser enables the material to evaporate and deposit on the surface of the substrate 1 with high quality. PLD technology can achieve very high film quality, especially suitable for preparing high-purity, well-crystalline films, and suitable for making optoelectronic materials with strict requirements such as three-dimensional topological insulators. It can also accurately control the deposition thickness in a short time, especially when the requirements for film thickness are very high, it can ensure the uniformity and consistency of the deposited layer, and is suitable for depositing 1 micron thick three-dimensional topological insulators.

[0081] Three-dimensional topological insulators such as antimony telluride (Sb2Te3), bismuth telluride (Bi2Te3), bismuth selenide (Bi2Se3), etc. have unique topological surface states and insulator states, which help to improve the performance of light-absorbing metasurfaces. Through magnetron sputtering or pulsed laser deposition technology, these materials can be uniformly and accurately deposited on the substrate to form a 1-micron thick three-dimensional topological insulator layer. Magnetron sputtering is suitable for large-area deposition and cost control, while pulsed laser deposition can provide higher film quality and fine thickness control. Those skilled in the art can choose the appropriate technology according to specific actual needs (such as film quality, deposition area and cost control).

[0082] In S730, a plurality of light absorption units 21 arranged in an array as described above are prepared on the three-dimensional topological insulator by using focused ion beam, laser processing or electron beam lithography technology.

[0083] Focused ion beam technology uses high-energy ion beams to precisely carve and process the surface of materials. Ion beams have high energy density and can cut, deposit and modify materials at the nanoscale. It can provide extremely high processing accuracy and is suitable for manufacturing nanoscale light absorption units 21. It can not only accurately control the structural dimensions to ensure that the geometry of each light absorption unit 21 meets the design requirements, but also can perform fine processing on local areas of the material without the need for batch processing of the entire material, which is suitable for preparing complex light absorption unit 21 arrays on the surface of three-dimensional topological insulators.

[0084] Laser processing technology uses a high-intensity laser beam to heat the surface of the material, causing the material to melt or vaporize in the laser irradiation area, thereby achieving cutting, engraving and surface modification. Laser processing can adjust the processing effect by precisely controlling the energy, pulse width and irradiation time of the laser. In addition, laser processing is non-contact, which can reduce the impact of mechanical stress on the material and avoid material deformation or damage that may be caused by traditional mechanical processing. It is suitable for precise micro-nanostructure processing. In addition, laser processing technology usually has a high processing speed and is suitable for rapid manufacture of light absorption unit 21 arrays on large-area substrates.

[0085] Electron beam lithography uses a focused electron beam to irradiate a substrate coated with a photosensitive material (such as polymethyl methacrylate, PMMA). The radiation of the electron beam changes the chemical properties of the photosensitive material, and forms a micro-nanoscale structure through the development process. Electron beam lithography can accurately carve the required pattern on the surface of the material or film by adjusting the energy, scanning speed and exposure time of the electron beam. Electron beam lithography can provide extremely high spatial resolution, usually reaching the nanometer level, suitable for manufacturing complex and high-precision light absorption units21, and has a high degree of flexibility. It can process a variety of different materials and can accurately adjust the shape and size of the lithographic pattern to meet the manufacturing needs of complex structures.

[0086] Whether it is focused ion beam, laser processing or electron beam lithography technology, it is possible to achieve nano-level fine processing on the surface of the three-dimensional topological insulator. Therefore, those skilled in the art can select a suitable method to prepare the light absorption units 21 arranged in several arrays as described above on the three-dimensional topological insulator according to actual conditions, and the present invention does not make specific restrictions.

[0087] Other embodiments of the invention will readily occur to those skilled in the art after considering the specification and practicing 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 exact construction that has been described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the present 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 absorption layer includes a plurality of light absorption units arranged in an array, and is used to absorb light waves in the 400-2000 nanometer band; A substrate is arranged below the supersurface light absorbing layer and is used to support the supersurface light absorbing layer.

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

3. The high-efficiency, wide-spectrum light-absorbing metasurface according to claim 1, characterized in that: The light absorbing unit comprises: a first light absorber, a second light absorber, disposed adjacent to the first light absorber; There is a first groove between the first light absorber and the second light absorber, and the first light absorber and the second light absorber are in an axisymmetric structure about the center of the first groove, so that the first groove has a first isosceles triangle cross-section.

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

5. The high-efficiency, wide-spectral-range light-absorbing metasurface according to claim 3, characterized in that: A second groove is provided between two adjacent light absorbing units, and the two adjacent light absorbing units are in an axisymmetric structure about the center of the second groove, so that the second groove has a second isosceles triangle cross-section.

6. The high-efficiency, wide-spectral-range light-absorbing metasurface according to claim 5, characterized in that: The height of the second isosceles triangle cross section is 300-400 nanometers, and the length of the base is 200-280 nanometers.

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

8. The high-efficiency, wide-spectral-range light-absorbing metasurface according to claim 5, characterized in that: The distance between the first isosceles triangle vertex and the second isosceles triangle vertex is 300-400 nanometers.

9. The high-efficiency, wide-spectrum light-absorbing metasurface according to any one of claims 1 to 8, characterized in that: The substrate is made of silicon dioxide, silicon, sapphire or metal.

10. A method for preparing a light-absorbing metasurface, characterized in that: The method for preparing the light absorbing metasurface comprises: Determine the substrate material to be silicon dioxide, silicon, sapphire or metal; Using magnetron sputtering or pulsed laser deposition technology to deposit 1 micron three-dimensional topological insulators; A plurality of light absorption units arranged in an array as described in any one of claims 1 to 9 are prepared on the three-dimensional topological insulator using focused ion beam, laser processing or electron beam lithography technology.

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