A visible light near infrared metamaterial absorber

Abstract

The present invention discloses a visible light near-infrared metamaterial absorber, which comprises M×N units, where M and N are both positive integers greater than or equal to 2; each unit consists of a resonant layer, a dielectric layer and a metal bottom layer; the resonant layer is a pattern formed by the two-dimensional material Ti3C2T x The visible light near-infrared metamaterial absorber proposed by the present invention achieves perfect absorption with an absorption rate of 99% in a relatively wide absorption band, and the absorption rate remains unchanged within this absorption band, and the absorption band exhibits a flat-top characteristic. In addition, the period of the absorber provided by the present invention has a good tolerance to processing errors.

Description

Technical Field

[0001] The present invention relates to the technical field of optoelectronic devices, and in particular to a visible light near-infrared metamaterial absorber. Background Art

[0002] Visible light near-infrared absorbers have important applications in energy storage, photovoltaic energy conversion, etc. In order to improve energy storage and absorption efficiency, absorptivity and absorption bandwidth are two very important technical indicators for visible light near-infrared absorbers. Metamaterial absorbers have attracted much attention due to their ability to achieve perfect absorption (i.e., an absorption rate of more than 99% and close to 100%), but their inherent absorption bandwidth is very narrow. Although researchers have also proposed some methods to expand the absorption bandwidth, among the visible light near-infrared metamaterial absorbers reported so far, most of the broadband absorption is only above 90%, and the absorption bandwidth close to 100% is still very narrow. In addition, the period of the visible light near-infrared metamaterial absorbers reported so far has a relatively large impact on the absorption performance, and the absorption energy will change significantly when the period changes.

[0003] Based on the above problems, how to design visible light near-infrared metamaterial absorbers so that they can achieve perfect absorption in a wider absorption band and keep the absorption performance unchanged at different periods has become an urgent problem to be solved in this field. Summary of the invention

[0004] To achieve the above object, the present invention provides the following solutions:

[0005] A visible light near-infrared metamaterial absorber, characterized in that: the absorber is a periodic structure, including M×N units, adjacent units have no spacing, and M and N are both positive integers greater than or equal to 2;

[0006] The unit has a three-layer structure, which is a resonance layer, a dielectric layer and a metal bottom layer in sequence along the wave incident direction;

[0007] The cross-sections of the layers are all square; the line connecting the center of the resonant layer and the centers of the dielectric layer and the metal bottom layer is perpendicular to the resonant layer, the dielectric layer and the metal bottom layer;

[0008] The material of the resonance layer is a two-dimensional material Ti3C2T x ;

[0009] The resonant layer is formed by a pattern; the dielectric layer and the metal bottom layer are a whole layer of material without a pattern;

[0010] The resonance layer is composed of a square patch located in the center and four strip patches surrounding the square patch; the side length of the resonance layer is equal to the sum of the side length of the square patch and twice the width of the strip patches.

[0011] Optionally, the thickness of the resonance layer is 30-50 nm.

[0012] Optionally, the material of the dielectric layer is any one of silicon, silicon dioxide or aluminum oxide, and the thickness is 100-150 nm.

[0013] Optionally, the material of the metal bottom layer is any one of gold or silver, and the thickness is 20-50 nm.

[0014] Optionally, the side length of the unit is 300-600nm.

[0015] Optionally, the side length of the square patch is 160-500 nm.

[0016] Optionally, the strip-shaped patch has a length of 100-300 nm and a width of 50-70 nm.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The present invention provides a visible light near-infrared metamaterial absorber, the absorber has an absorptivity higher than 90% in the wavelength range of 626-963nm, and an absorptivity of 99% in the wavelength range of 693-897nm, achieving perfect absorption; in addition, the absorptivity remains unchanged in the wavelength range of 693-897nm, and the absorption band is flat-topped; the absorber changes in period, i.e., the side length of a unit; when the period, i.e., the side length of a unit, changes in the absorber, the absorbing performance changes very little, i.e., the period of the absorber has a good tolerance to processing errors. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0020] Figure 1 This is a schematic diagram of the structure of a single unit of a visible light near-infrared metamaterial absorber according to an embodiment of the present invention;

[0021] Figure 2 It is a side view of a single unit of the visible light near-infrared metamaterial absorber according to an embodiment of the present invention;

[0022] Figure 3 This is a schematic diagram of the resonance layer structure of a single unit of a visible light near-infrared metamaterial absorber according to an embodiment of the present invention;

[0023] Figure 4This is an absorption response diagram of a visible light near-infrared metamaterial absorber according to an embodiment of the present invention;

[0024] Figure 5 This is an absorption response diagram of different periods of the visible light near-infrared metamaterial absorber according to an embodiment of the present invention.

[0025] Among them, 1. resonant layer, 2. dielectric layer, 3. metal bottom layer, 4. square patch, 5. strip patch. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] The present invention provides a visible light near-infrared metamaterial absorber. The absorber is a periodic structure, composed of M×N identical units, with no spacing between adjacent units, and M and N are both integers greater than or equal to 2.

[0029] Figure 1 This is a schematic diagram of the structure of a single unit of a visible light near-infrared metamaterial absorber according to an embodiment of the present invention; Figure 2 FIG. 1 is a side view of a single unit array of a visible light near infrared metamaterial absorber according to an embodiment of the present invention. Figure 1 and Figure 2 As shown, the unit of the absorber in the embodiment of the present invention is a three-layer structure, namely, a resonance layer 1, a dielectric layer 2 and a metal bottom layer 3. The cross section of each layer is a square. The line connecting the center of the resonance layer 1 and the centers of the dielectric layer 2 and the metal bottom layer 3 is perpendicular to the resonance layer 1, the dielectric layer 2 and the metal bottom layer 3. In this embodiment, the material of the resonance layer 1 is a two-dimensional material Ti3C2T x The material of the dielectric layer 2 is silicon dioxide, and its thickness h2 is 100nm; the material of the metal bottom layer 3 is gold, and its thickness h3 is 20nm. The resonance layer 1 is composed of patterns; the dielectric layer 2 and the metal bottom layer 3 are a whole layer of material without patterns.

[0030] Figure 3 FIG. 1 is a schematic diagram of the resonant layer structure of a single unit of a visible light near infrared metamaterial absorber according to an embodiment of the present invention. Figure 3As shown, the resonant layer 1 is composed of a square patch 4 located in the center and four strip patches 5 surrounding the square patch; the side length P of the resonant layer is equal to the sum of the side length d of the square patch 4 and twice the width w of the strip patch, that is, P = d + 2w. In this embodiment, the side length P of the single transmission unit is 600nm; the side length d of the square patch 4 is 500nm; the length l of the strip patch 5 is 300nm, and the width w is 50nm.

[0031] Figure 4 This is the absorption response diagram of the visible light near-infrared metamaterial absorber of the embodiment of the present invention. It can be seen from the figure that the absorber has an absorption rate of more than 90% in the wavelength range of 626-963nm and reaches 99% in the range of 693-897nm, achieving perfect absorption. In addition, the absorption rate remains unchanged in the wavelength range of 693-897nm, and the absorption band is flat-topped.

[0032] Figure 5 The absorption response of the visible light near infrared metamaterial absorber at different periods of the embodiment of the present invention is shown in the figure. It can be seen from the figure that when the period, that is, the unit side length, of the absorber changes, the absorbing performance remains basically unchanged.

[0033] The visible light near infrared metamaterial absorber in this embodiment has an absorption rate higher than 90% in the wavelength range of 626-963nm, and an absorption rate of up to 99% in the wavelength range of 693-897nm. The absorber has a wide absorption band, and the band for achieving perfect absorption (up to 99% absorption rate) is also wide. In addition, the absorption rate remains unchanged in the wavelength range of 693-897nm, and the absorption band is flat-topped; when its period changes, the absorbing performance remains basically unchanged, that is, it has a good tolerance for periodic processing errors.

[0034] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A visible light near infrared metamaterial absorber, characterized in that: The absorber is a periodic structure, including M×N units, adjacent units have no spacing, and M and N are both positive integers greater than or equal to 2; The unit has a three-layer structure, which is a resonant layer, a dielectric layer and a metal bottom layer in sequence along the wave incident direction; The cross-sections of the layers are all square; the line connecting the center of the resonant layer and the centers of the dielectric layer and the metal bottom layer is perpendicular to the resonant layer, the dielectric layer and the metal bottom layer; The material of the resonance layer is a two-dimensional material Ti3C2T x ; The resonant layer is formed by a pattern; the dielectric layer and the metal bottom layer are a whole layer of material without a pattern; The resonance layer is composed of a square patch located in the center and four strip patches surrounding the square patch; the side length of the resonance layer is equal to the sum of the side length of the square patch and twice the width of the strip patches.

2. The visible light near infrared metamaterial absorber according to claim 1, characterized in that: The thickness of the resonance layer is 30-50 nm.

3. The visible light near infrared metamaterial absorber according to claim 1, characterized in that: The material of the dielectric layer is any one of silicon, silicon dioxide or aluminum oxide, and the thickness is 100-150nm.

4. The visible light near infrared metamaterial absorber according to claim 1, characterized in that: The material of the metal bottom layer is any one of gold or silver, and the thickness is 20-50nm.

5. The visible light near infrared metamaterial absorber according to claim 1, characterized in that: The side length of the unit is 300-600 nm.

6. The visible light near infrared metamaterial absorber according to claim 1, characterized in that: The side length of the square patch is 160-500 nm.

7. The visible light near infrared metamaterial absorber according to claim 1, characterized in that: The strip-shaped patch has a length of 100-300 nm and a width of 50-70 nm.

Images