Solar absorber based on I-shaped and cross-shaped antennas

Abstract

The present invention relates to a solar absorber based on an I-shaped structure and a cross-shaped antenna, belonging to the field of micro-nano optoelectronic technology. The solar absorber absorbs sunlight incident by plane waves and is composed of multiple identical unit structures periodically arranged in an XOY plane. Each unit structure includes, from bottom to top, a base layer, a buffer layer, and an antenna layer. The antenna layer includes, from bottom to top, a metal layer and a non-metal layer, which are completely consistent in shape and size. The base layer and the buffer layer are projected onto the XOY plane in the same square shape, while the antenna is projected onto the XOY plane in the shape of an I-beam and a cross. The present invention has a simple structure and can achieve an average absorption rate of 93.77% within a broadband range of 451nm to 1449nm. In addition, the present invention has a good absorption effect when incident with different polarized light and at different incident angles.

Description

Technical Field

[0001] The invention discloses a solar energy absorber based on an I-shaped structure and a cross-shaped structure antenna, belonging to the technical field of micro-nano optoelectronics. Background Art

[0002] Metasurfaces are artificially designed periodic structures. Due to their unique electromagnetic properties, tunable refractive index, and asymmetric transmission characteristics, they are often used to create highly efficient electromagnetic wave absorbers for solar energy. However, sunlight has a broad spectrum and widely varying incident angles. Therefore, how to efficiently utilize solar energy in these conditions has become a major research topic for metasurfaces.

[0003] Currently, the typical approach to achieving broadband absorption is to arrange multiple metal resonators in a cellular structure, as these resonators have different peak absorption positions. Broadband absorption is achieved by superimposing the absorption peaks generated by these different metal resonators. However, this approach also has its limitations. Due to the competition between different resonators, the number of resonators is limited. In addition, noble metals are widely used to manufacture various absorbers due to their plasmon resonance and light coupling properties. However, the high cost and low natural reserves of noble metals make them unsuitable for large-scale processing, so a more common method for preparing absorbers is needed. Since the metal-insulator-metal structure was proposed in 2008, metamaterials have been used to develop narrowband or broadband absorbers. In recent years, a wide variety of solar metastructure absorbers have been gradually designed by researchers from various countries. However, most absorbers have some shortcomings, such as poor broadband performance, low absorptivity, or the absorption bandwidth cannot match the energy distribution of the solar spectrum, resulting in low absorption effect. Summary of the Invention

[0004] To address the above problems, the present invention designs a solar absorber based on an I-shaped structure and a cross-shaped structure antenna. The structure is simple and can achieve an average absorption rate of 93.77% within a broadband range of 451nm to 1449nm. In addition, the present invention has good absorption effects when incident on light with different polarizations and at different incident angles.

[0005] The object of the present invention is achieved like this:

[0006] A solar absorber based on an I-shaped and cross-shaped antenna structure absorbs incident sunlight in the form of a plane wave. The solar absorber is composed of multiple identical unit structures periodically arranged in an XOY plane. Each unit structure includes, from bottom to top, a substrate layer, a buffer layer, and an antenna layer. The antenna layer includes, from bottom to top, a metal layer and a non-metal layer. The metal layer and the non-metal layer are identical in shape and size.

[0007] The projections of the base layer and the buffer layer onto the XOY plane are identical squares, the boundaries of the squares are parallel to the X-axis and the Y-axis, and the projections of the antenna onto the XOY plane are I-shaped and cross-shaped, the horizontal and vertical sides of the I-shaped being parallel to the X-axis and the Y-axis, respectively, and the I-shaped being located in the middle of the square, the horizontal and vertical sides of the cross intersecting at the center of the boundary of the buffer layer, and the vertical side of the cross coinciding with the boundary of the buffer layer;

[0008] The material of the base layer is titanium, the material of the buffer layer is silicon dioxide, the material of the metal layer is titanium, and the material of the non-metal layer is titanium nitride.

[0009] The above-mentioned solar absorber based on I-shaped and cross-shaped antennas is characterized in that:

[0010] The projection size of the base layer on the XOY plane is 0.4 μm×0.4 μm, and the height is greater than 0.5 μm;

[0011] The projected size of the buffer layer on the XOY plane is 0.4 μm×0.4 μm, and the height is 0.07 μm;

[0012] In the antenna layer, the height of the metal layer and the non-metal layer is 0.02 μm. In the I-shape, the horizontal length is 0.2 μm and the width is 0.08 μm. The vertical length is 0.2 μm and the width is 0.08 μm. In the cross shape, the horizontal and vertical lengths are 0.18 μm and the width is 0.05 μm. The center distance between the I-shape and the cross shape is 0.2 μm.

[0013] Beneficial effects:

[0014] First, the solar absorber based on the I-shaped structure and the cross-shaped structure antenna of the present invention only includes three components: a base layer, a buffer layer and an antenna. Compared with other solar absorbers, it has the technical advantages of simple structure and easy processing.

[0015] Second, the solar absorber based on the I-shaped and cross-shaped antennas of the present invention has a good absorption effect when the light source is incident with different polarizations, and has the technical advantage of being polarization-insensitive.

[0016] Third, the solar absorber based on the I-shaped structure and cross-shaped structure antenna of the present invention has an average absorption rate of up to 93.77% in the broadband range of 451nm to 1449nm. Compared with other solar absorbers, it has the technical advantages of broadband and high absorption rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the solar absorber based on the I-shaped structure and the cross-shaped structure antenna of the present invention.

[0018] Figure 2 It is a structural diagram of a single unit structure.

[0019] Figure 3 It is a schematic diagram of parameter definition of a single unit structure.

[0020] Figure 4 This is a screenshot of the simulation software interface of the present invention.

[0021] Figure 5 for Figure 4 Absorption effect curve in .

[0022] Figure 6 This is the absorption rate curve when the length of the upper and lower sides of the I-shaped antenna changes.

[0023] Figure 7 This is the absorption rate curve when the width of the upper and lower sides of the I-shaped antenna changes.

[0024] Figure 8 It is the absorptivity curve of the absorber when the incident angle of the light source changes from 0° to 45°.

[0025] Figure 9 It is the absorptivity curve of the absorber when the polarization angle of the light source changes from 0° to 90°.

[0026] In the figure: 1 base layer, 2 buffer layer, 3 antenna layer, 3-1 metal layer, 3-2 non-metal layer. DETAILED DESCRIPTION

[0027] The specific embodiments of the present invention are further described in detail below with reference to the accompanying drawings. Specific implementation method 1

[0029] The solar absorber based on the I-shaped structure and the cross-shaped structure antenna in this specific embodiment absorbs the incident sunlight of the plane wave, and is composed of multiple identical unit structures periodically arranged in the XOY plane, such as Figure 1 As shown, each of the unit structures includes a base layer 1, a buffer layer 2 and an antenna layer 3 from bottom to top; the antenna layer 3 includes a metal layer 3-1 and a non-metal layer 3-2 from bottom to top, and the shapes and sizes of the metal layer 3-1 and the non-metal layer 3-2 are completely consistent, as shown in FIG. Figure 2 As shown;

[0030] The projections of the base layer 1 and the buffer layer 2 onto the XOY plane are identical squares, the boundaries of the squares are parallel to the X-axis and the Y-axis, and the projections of the antenna 3 onto the XOY plane are I-shaped and cross-shaped, the horizontal and vertical portions of the I-shaped being parallel to the X-axis and the Y-axis, respectively, and the I-shaped being located in the middle of the square, the horizontal and vertical portions of the cross intersecting at the center of the boundary of the buffer layer 2, and the vertical portion of the cross coinciding with the boundary of the buffer layer 2;

[0031] The material of the base layer 1 is titanium, the material of the buffer layer 2 is silicon dioxide, the material of the metal layer 3 - 1 is titanium, and the material of the non-metal layer 3 - 2 is titanium nitride.

[0032] The parameter definition diagram of the solar absorber based on the I-shaped structure and cross-shaped structure antenna is as follows: Figure 3 As shown,

[0033] The projection size of the base layer 1 on the XOY plane is 0.4 μm×0.4 μm, and the height is greater than 0.5 μm;

[0034] The projected size of the buffer layer 2 on the XOY plane is 0.4 μm×0.4 μm, and the height is 0.07 μm;

[0035] In the antenna layer 3, the height of the metal layer 3-1 and the non-metal layer 3-2 are both 0.02μm. In the I-shape, the horizontal length is 0.2μm and the width is 0.08μm. The vertical length is 0.2μm and the width is 0.08μm. In the cross shape, the horizontal and vertical lengths are both 0.18μm and the width is 0.05μm. The center distance between the I-shape and the cross shape is 0.2μm. Specific implementation method 2

[0037] In this embodiment, the solar absorber based on the I-shaped structure and the cross-shaped structure antenna uses the FDTD-Solutions software to simulate the influence of the structural parameters of the metal layer 3-1 and the non-metal layer 3-2 in the antenna 3, the light source incident angle, the light source polarization angle and other variables on the absorption rate. The simulation interface is shown as follows: Figure 4 As shown, Figure 4 The absorption effect curve in Figure 5 As shown, the average absorption rate is calculated using the following formula and is 93.77%.

[0038]

[0039] Where A is the average absorptivity of the absorber, λ is the wavelength of the incident light, and A is the function of the absorber's absorber strength as a function of the wavelength of the incident light. Specific implementation method three

[0041] The solar absorber based on the I-shaped structure and the cross-shaped structure antenna in this specific embodiment simulates the length of the upper and lower sides of the I-shaped antenna. When the length changes from 0.12μm to 0.28μm, the absorption rate curve is as follows: Figure 6 As shown, it can be seen that as the length increases, the absorption peak at short wavelength blue-shifts, the absorption peak at long wavelength remains basically unchanged, and the overall absorptivity shows an upward trend. When the length is greater than 0.2 μm, the bandwidth range where the absorptivity is greater than 90% becomes narrower. Specific implementation method four

[0043] The solar absorber based on the I-shaped structure and the cross-shaped structure antenna in this specific embodiment simulates the length and width of the upper and lower sides of the I-shaped antenna. When the width changes from 0.12μm to 0.28μm, the absorption rate curve is as follows: Figure 7 As shown, it can be seen that as the width increases, the absorption peak at short wavelength red-shifts, and the peak height remains basically unchanged, while the absorption peak at long wavelength increases, and the position remains basically unchanged. Specific implementation method five

[0045] The solar absorber based on the I-shaped structure and the cross-shaped structure antenna in this specific embodiment is based on the specific embodiment 1. The influence of the angle change of the incident sunlight on the absorption rate is simulated and tested at the incident angles of 0°, 5°, 10°, 15°, 20°, 25°, 30°, 35°, 40° and 45°, as shown in FIG. Figure 8 As shown in FIG. 1 , the absorption rate shows an overall downward trend when the incident angle of the light source is changed, and the absorption rate is 89.7% when the light source is incident at an angle of 45°. Specific implementation method six

[0047] The solar absorber based on the I-shaped structure and the cross-shaped structure antenna in this specific embodiment is based on the specific embodiment 1. The influence of the change of the polarization angle of sunlight on the absorption rate is simulated and tested at the polarization angles of 0°, 10°, 20°, 30°, 40°, 50°, 60°, 70°, 80° and 90°, as shown in FIG. Figure 9 As shown in FIG. 1 , the absorptivity shows an overall downward trend when the polarization angle of the light source is changed. When the light source is incident at a polarization angle of 90°, the absorptivity is 91.8%.

Claims

1. A solar absorber based on an I-shaped structure and a cross-shaped structure antenna, which absorbs incident sunlight from a plane wave, is composed of a plurality of identical unit structures periodically arranged in an XOY plane, wherein each unit structure comprises, from bottom to top, a base layer (1), a buffer layer (2), and an antenna layer (3); and the antenna layer (3) comprises, from bottom to top, a metal layer (3-1) and a non-metal layer (3-2); The projection shapes of the base layer (1) and the buffer layer (2) onto the XOY plane are the same square, and the boundaries of the square are parallel to the X axis and the Y axis; The material of the base layer (1) is titanium, the material of the buffer layer (2) is silicon dioxide, and the material of the metal layer (3-1) is titanium; It is characterized in that The projection shape of the antenna (3) onto the XOY plane is an I-shape and a cross-shape, the horizontal and vertical portions of the I-shape are parallel to the X-axis and the Y-axis respectively, and the I-shape is located in the middle of the square, the horizontal and vertical portions of the cross-shape intersect at the center of the boundary of the buffer layer (2), and the vertical portion of the cross-shape coincides with the boundary of the buffer layer (2); The metal layer (3-1) and the non-metal layer (3-2) are completely consistent in shape and size; the material of the non-metal layer (3-2) is titanium nitride.

2. The solar absorber based on the I-shaped structure and the cross-shaped structure antenna according to claim 1, characterized in that: The projection size of the base layer (1) on the XOY plane is 0.4 μm×0.4 μm, and the height is greater than 0.5 μm; The buffer layer (2) has a projection size of 0.4 μm×0.4 μm on the XOY plane and a height of 0.07 μm; In the antenna layer (3), the height of the metal layer (3-1) and the non-metal layer (3-2) are both 0.02 μm. In the I-shape, the horizontal length is 0.2 μm and the width is 0.08 μm. The vertical length is 0.2 μm and the width is 0.08 μm. In the cross shape, the horizontal and vertical lengths are both 0.18 μm and the width is 0.05 μm. The center distance between the I-shape and the cross shape is 0.2 μm.

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