A metamaterial wave absorber with broadband perfect absorption performance

Abstract

This invention discloses a metamaterial absorber with broadband perfect absorption performance. The absorber has a periodic structure, and each unit consists of a Ti3C2T layer at the top. x It consists of a thin film, an intermediate dielectric layer, and a bottom metal backplate; Ti3C2T x The thin film has a circular perforation. The absorber provided by this invention has a broadband absorption of over 90% in the wavelength range of 685-983nm, and can achieve perfect absorption of over 99% in the wavelength range of 748-854nm, and its periodicity has good tolerance to processing errors.

Description

Technical Field

[0001] This invention relates to the fields of electromagnetic metamaterials and electromagnetic signal shielding, and in particular to a metamaterial absorber with broadband perfect absorption performance. Background Technology

[0002] Metamaterial absorbers represent an important application of electromagnetic metamaterials in the microwave, terahertz, and optical frequency bands. Since Landy et al. first proposed metamaterial absorbers with near-100% absorption (i.e., perfect absorption) in 2008, metamaterial absorbers have attracted widespread attention due to their excellent absorption performance, compact structure, and thin thickness. However, due to the inherent resonant absorption mechanism, the initially designed metamaterial absorbers, while achieving perfect absorption, had relatively narrow absorption bandwidths, especially since the perfect absorption region was essentially a very narrow band centered on a single frequency point. To adapt to broadband absorption applications, several methods have been proposed to realize broadband metamaterial absorbers, such as using multilayer structures, multiple resonators, and functional materials. To date, among the reported broadband metamaterial absorbers, although the absorption bandwidth is relatively wide, this generally refers to a wide bandwidth with an absorptivity greater than 90%, while the bandwidth achieving perfect absorption (nearly 100% absorption) remains very narrow. In fact, designing metamaterial absorbers with a wide perfect absorption range remains a challenge. Summary of the Invention

[0003] Therefore, it is necessary to propose a metamaterial absorber with broadband perfect absorption performance.

[0004] To achieve the above objectives, the present invention provides the following solution:

[0005] A metamaterial wave absorber with broadband perfect absorption performance is characterized in that: the wave absorber is a side-length structure, comprising M×N units, with no spacing between adjacent units, and M and N are both positive integers greater than or equal to 2;

[0006] The unit has a three-layer structure, including a top Ti3C2T x Thin film, intermediate dielectric layer, and bottom metal backplate;

[0007] Each layer is a regular hexagon, and the centers of each layer are aligned vertically, wherein Ti3C2T x The thin film has a circular perforation, the center of which is located at Ti3C2T x The centers of the films coincide.

[0008] Optionally, the metal backing plate is made of either gold or silver, and has a thickness of 60-80 nm.

[0009] Optionally, the dielectric layer is made of any one of silicon, silicon dioxide, and aluminum oxide, and has a thickness of 100-150 nm.

[0010] Optionally, the Ti3C2T x The thickness of the thin film is 30-50 nm.

[0011] Optionally, the side length of each layer is 250-280 nm.

[0012] Optionally, the inner diameter of the annular cutout is 160-170 nm, and the width is 20-25 nm.

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

[0014] This invention proposes a metamaterial absorber with broadband perfect absorption performance. The absorber has an absorption rate of over 90% in the wavelength range of 685-983nm and a perfect absorption rate of up to 99% in the wavelength range of 748-854nm. The absorber has good wide-angle absorption capability. The absorber provided by this invention has a simple structure and its period has good tolerance to processing errors. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the structure of a single unit of a metamaterial absorber with broadband perfect absorption performance according to an embodiment of the present invention;

[0017] Figure 2 This is a side view of a single unit of a metamaterial absorber with broadband perfect absorption performance according to an embodiment of the present invention;

[0018] Figure 3 This invention relates to a single unit of a metamaterial absorber with broadband perfect absorption performance, specifically Ti3C2T. x Schematic diagram of thin film structure;

[0019] Figure 4 The above is the absorption characteristic curve of the metamaterial absorber with broadband perfect absorption performance according to an embodiment of the present invention;

[0020] Figure 5 The above are absorption characteristic curves of a metamaterial absorber with broadband perfect absorption performance in TE mode at different incident angles according to an embodiment of the present invention.

[0021] Figure 6 The above are absorption characteristic curves of a metamaterial absorber with broadband perfect absorption performance in TM mode at different incident angles according to an embodiment of the present invention.

[0022] Figure 7 The graphs show the absorption characteristics of a metamaterial absorber with broadband perfect absorption performance under different side lengths, according to an embodiment of the present invention.

[0023] Among them, 1. metal backplate, 2. dielectric layer, 3. Ti3C2T x film. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] This invention provides a metamaterial absorber with broadband perfect absorption performance, characterized in that: the absorber is a side-length structure comprising M×N units, with no spacing between adjacent units, and M and N are both positive integers greater than or equal to 2.

[0027] Figure 1 This is a schematic diagram of the structure of a single unit of a metamaterial absorber with broadband perfect absorption performance according to an embodiment of the present invention. Figure 2 This is a side view of a single unit of a metamaterial absorber with broadband perfect absorption performance according to an embodiment of the present invention. Figure 1 , 2 As shown, the absorber has a three-layer structure, including a top Ti3C2T layer. x Thin film 3, middle dielectric layer 2, and bottom metal backplate 1, the thicknesses of each layer are as follows: the thickness of metal backplate 1 is a, the thickness of dielectric layer 2 is b, Ti3C2T x The thickness of thin film 3 is c. In this embodiment, the material of the metal backplate 1 is gold, and the thickness a is 60 nm; the material of the dielectric layer 2 is silicon dioxide, and the thickness b is 100 nm; Ti3C2T x The thickness c of thin film 3 is 30 nm.

[0028] Figure 3 This invention relates to a single unit of a metamaterial absorber with broadband perfect absorption performance, specifically Ti3C2T. xSchematic diagram of the thin film. Figure 3 As shown, the Ti3C2T x The thin film has a circular perforation, the center of which coincides with the center of the top resonant layer. In this embodiment, Ti3C2T x The side length d of the thin film is 250nm; the inner diameter r of the annular perforation is 160nm, and the width w is 20nm.

[0029] Figure 4 The absorption characteristic curve of the absorber in the embodiment of the present invention shows that the absorber has an absorption rate of over 90% in the wavelength range of 685-983nm and a perfect absorption rate of up to 99% in the wavelength range of 748-854nm.

[0030] Figure 5 This is an embodiment of the present invention showing the absorption characteristics of a metamaterial absorber with broadband perfect absorption performance at different incident angles in TE mode. Figure 6 This is an example of the absorption characteristic curves of a metamaterial absorber with broadband perfect absorption performance at different incident angles in TM mode according to an embodiment of the present invention. Figure 6 and Figure 7 As shown, the absorber described in this invention has good wide-angle absorption capability.

[0031] Figure 7 The embodiments of the present invention show the absorption characteristic curves of a metamaterial absorber with broadband perfect absorption performance at different side lengths. See also... Figure 7 When the side length of the absorber described in this invention is changed, the change in absorption performance is very small and basically remains unchanged. That is, the side length of the absorber provided by this invention has a good tolerance for processing errors.

[0032] The metamaterial absorber with broadband perfect absorption performance in this embodiment has good broadband absorption capability. The wavelength range with an absorption rate of over 90% is 685-983nm, and the wavelength range with an absorption rate of over 99%, i.e., perfect absorption, is 748-854nm, exhibiting a wide perfect absorption bandwidth. Its absorption performance is good under different incident angles. The structure is simple, and more importantly, the side length has a good tolerance for processing errors. That is, the absorber provided by this invention has relatively low requirements for processing precision and is easy to process.

[0033] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A metamaterial absorber with broadband perfect absorption performance, characterized in that: The absorber has a periodic structure, comprising M×N units, with no spacing between adjacent units, where M and N are both positive integers greater than or equal to 2; The unit has a three-layer structure, including a top Ti3C2T x Thin film, intermediate dielectric layer, and bottom metal backplate; Each layer is a regular hexagon, and the centers of each layer are aligned vertically, wherein Ti3C2T x The thin film has a circular perforation, the center of which is located at Ti3C2T x The centers of the thin films coincide; The top resonant layer Ti3C2T x The thickness of the thin film is 30-50 nm; The intermediate dielectric layer is made of any one of silicon, silicon dioxide, and aluminum oxide, and has a thickness of 100-150 nm. The side length of each layer is 250-280 nm; The inner diameter of the circular cutout is 160-170 nm, and the width is 20-25 nm. The absorber has an absorption rate of over 90% in the wavelength range of 685-983 nm and a perfect absorption rate of up to 99% in the wavelength range of 748-854 nm.

2. The metamaterial absorber with broadband perfect absorption performance according to claim 1, characterized in that, The metal backing plate is made of either gold or silver and has a thickness of 60-80 nm.

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