Absorber comprising embedded body

Abstract

The absorber is formed by periodically arranging a plurality of absorption structure units, each absorption structure unit comprises a SiO2 substrate, a Ti metal layer and two Si3N4 regular hexagonal prisms which are coaxially arranged from bottom to top, and the embedded body which is coaxially arranged in the Si3N4 regular hexagonal prism at the bottom layer; the embedded body comprises an MgF2 regular hexagonal prism on the outer layer, a Cr metal circular ring on the middle layer and a TiO2 regular hexagonal prism on the inner layer. When the MgF2 regular hexagonal prism is internally tangent to the Si3N4 regular hexagonal prism at the bottom layer, the Cr metal circular ring is internally tangent to the MgF2 regular hexagonal prism, the TiO2 regular hexagonal prism is internally tangent to the Cr metal circular ring, and the top point of the bottom surface of the Si3N4 regular hexagonal prism at the top layer coincides with the midpoint of the edge of the top surface of the Si3N4 regular hexagonal prism at the bottom layer, it is ensured that an electromagnetic field / sound field is uniformly coupled between structural units, energy leakage or too high local field intensity is avoided, and the electromagnetic field / sound field is effectively improved. The coverage range of absorbed waves is 800-2800nm, and is not influenced by incident energy polarization, so that the application range is wide; structural unit layout facilitates accurate alignment, manufacturing difficulty and cost are reduced, and mass production, popularization and application are easy.

Description

TECHNICAL FIELD

[0001] The present invention relates to an absorber, and more particularly to an absorber with super-wideband and polarization-insensitive containing an inlay. BACKGROUND

[0002] Metamaterial is a kind of artificial composite material or composite structure with super macroscopic physical properties composed of unit structures according to specific spatial arrangement, which is widely used in energy collection, sub-wavelength imaging, perfect absorber, photovoltaic device and other fields. Metamaterial absorber working in microwave band was first proposed by Landy IN in 2008. This kind of electromagnetic absorber breaks through the limitations of traditional electromagnetic absorption materials. Optical perfect absorber is a kind of artificial structure material that can realize nearly 100% light absorption in a specific or wide spectral range. Its core principle is to control the propagation and loss of light through precisely designed micro-nano structures, realize impedance matching and critical coupling, and thus maximize the suppression of reflection and transmission, and efficiently convert incident light energy into heat or other forms of energy. This kind of electromagnetic absorber has broad application prospects in sensing, energy conversion, imaging and invisibility cloak[3], and scholars gradually increase the research on this kind of absorber. Lei J G, Ji B Y & Lin JQ. A high-performance light absorber based on a metamaterial nanopyramid array[J]. Chinese Journal of Physics, 2016, 54(6): 940-946, designed a kind of absorber based on nanopyramid array, the working wave band of the absorber covers near infrared wave band, the absorber shows super flat and nearly 100% absorption performance in 200nm-3600nm incident wave band; Qin Z, Shi XY, Yang F M, et al. Multi-mode plasmonic resonance broadband LWIR metamaterial absorber based on lossy metal ring[J]. Optics Express, 2022, 30(1): 473-483, designed a broadband long-wave infrared metamaterial absorber based on metal-dielectric-metal structure in the mid-infrared wave band. The average absorption rate of the absorber reaches 91.7%, and in the wavelength range of 7.5-13.25μm, 90% of the incident light is absorbed by the resonator. Although the above technologies have improved the absorption bandwidth and absorption rate, the design of multi-layer structure, the thickness and spacing of each layer will affect the reflection and absorption of the wave, the complex design increases the difficulty of device manufacturing, and the need to match resonators of different sizes limits its manufacturing, mass production and application. At the same time, the poor manufacturing precision enhances the sensitivity of the absorber to the polarization performance of the incident energy, further affecting its application. SUMMARY

[0003] The purpose of the present application is to provide an absorber with high absorption efficiency, simple structure, convenient production and polarization insensitivity in the near-infrared to mid-infrared spectral range.

[0004] Technical scheme: The absorber containing the inclusion is composed of a plurality of absorption structure units arranged periodically, the absorption structure unit comprises SiO2 substrate, Ti metal layer and two Si3N4 regular hexagonal prisms arranged coaxially from bottom to top, and the inclusion arranged coaxially in the bottom Si3N4 regular hexagonal prism; the inclusion comprises MgF2 regular hexagonal prism of the outer layer, Cr metal ring of the middle layer and TiO2 regular hexagonal prism of the inner layer; the bottom area of the bottom layer of the two Si3N4 regular hexagonal prisms is larger than that of the top layer, the plane formed by the center line of the vertical direction of the adjacent side of the top layer Si3N4 regular hexagonal prism and the bottom layer Si3N4 regular hexagonal prism is perpendicular to the side of the bottom layer Si3N4 regular hexagonal prism, the bottom edge of the MgF2 regular hexagonal prism is parallel to the bottom edge of the bottom layer Si3N4 regular hexagonal prism, and the bottom edge of the TiO2 regular hexagonal prism is parallel to the bottom edge of the top layer Si3N4 regular hexagonal prism.

[0005] Further, the inclusion is the same height as the bottom layer Si3N4 regular hexagonal prism.

[0006] Further, the SiO2 substrate and the Ti metal layer are square structure with the same bottom surface, and the side length is the same as the arrangement period P of the absorption structure unit. The structure period of the periodic absorber in the infrared wave band needs to be reduced to nanoscale, usually 200-500nm, to meet the subwavelength condition and excite the required electromagnetic resonance, such as surface plasmon resonance, photonic localization, etc. Through simulation experiment, it is obtained that the optimal parameter of P is 280-320nm, and the optimal period P is 300nm, and in order to control the size of the absorber, the total height of the structure unit is limited to be less than 3P.

[0007] Further, the half of the diagonal line distance r1 of the bottom surface regular hexagon of the bottom layer Si3N4 regular hexagonal prism is 120-150nm, the half of the diagonal line distance of the bottom surface regular hexagon of the top layer Si3N4 regular hexagonal prism is equal to the half of the diagonal line distance r2 of the bottom surface regular hexagon of the MgF2 regular hexagonal prism, the outer diameter r3 of the Cr metal ring is 92.5-132.5nm, the ring width a of the Cr metal ring is 2.5-22.5nm, and the half of the diagonal line distance r4 of the bottom surface regular hexagon of the TiO2 regular hexagonal prism is 80-110nm. There is a certain gap between each functional component, which may cause energy leakage or resonance frequency shift. If each functional component overlaps with each other, strong coupling may be caused, and the designed impedance matching is damaged.

[0008] Further, half of the diagonal distance of the bottom surface of the bottom layer Si3N4 regular hexagonal column is r1=150 nm, half of the diagonal distance of the bottom surface of the top layer Si3N4 regular hexagonal column is equal to half of the diagonal distance of the bottom surface of the MgF2 regular hexagonal column, r2=112.5 nm, the outer diameter of the Cr metal ring is r3=100 nm, the ring width of the Cr metal ring is a=12.5 nm, and half of the diagonal distance of the bottom surface of the TiO2 regular hexagonal column is r4=100 nm. At this time, the MgF2 regular hexagonal column is inscribed in the bottom layer Si3N4 regular hexagonal column, the Cr metal ring is inscribed in the MgF2 regular hexagonal column, the TiO2 regular hexagonal column is inscribed in the Cr metal ring, and the top of the bottom surface of the top layer Si3N4 regular hexagonal column is tangent to the midpoint of the edge of the top surface of the bottom layer Si3N4 regular hexagonal column, which can ensure uniform coupling of electromagnetic fields / acoustic fields between units, avoid energy leakage or excessive local field strength, and thus optimize absorption efficiency.

[0009] Further, the total height of the Ti metal layer is h1=230-270 nm, the height of the inlay body and the bottom layer Si3N4 regular hexagonal column is h2=160-230 nm, and the height of the top layer Si3N4 regular hexagonal column is h3=120-160 nm. Preferably, the total height of the Ti metal layer is h1=250 nm, the height of the inlay body and the bottom layer Si3N4 regular hexagonal column is h2=180 nm, and the height of the top layer Si3N4 regular hexagonal column is h3=140 nm.

[0010] Advantages: Compared with the prior art, the present application has the following advantages: 1. The absorber covers a range of 800 nm to 2800 nm, about 2000 nm, in the near-infrared to the mid-infrared, and has a wide range of applications; 2. The absorber effectively suppresses the loss of radiant energy, achieves an average absorption rate of 96.79% and a maximum absorption rate of 99.90% under TM waves, and achieves an average absorption rate of 95.79% and a maximum absorption rate of 99.86% under TE waves; 3. r1 has a greater impact on absorption rate, r2 is less important, r3 and r4 are comparable, and a and h1-h3 have a very small impact, which reduces the difficulty and cost of device production and makes it easier to mass-produce and apply; 4. Multiple regular hexagonal column functional components are arranged in rotational symmetry, the dielectric constant of amorphous Si3N4 has no directionality, and the metal Cr ring, which makes the interaction of electromagnetic fields in each direction consistent and insensitive to the polarization of incident energy, and the absorber has a nanoscale geometric difference in the X-Y direction cross section, the intrinsic polarization correlation caused by the nanoscale difference is balanced by the macroscopic symmetry, so that the absorption rate of the absorber is not affected by randomly polarized light or electromagnetic waves in the actual environment, achieving high-efficiency absorption in a wide spectral range without polarization influence, which has important application value in the field of solar photovoltaic conversion or concentrated solar energy and other renewable energy sources. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 (a) is a structural schematic diagram (5x5 period) of the present application, (b) is a top view of the inlaid broadband absorber with the top regular hexagonal prism removed, (c) is a split-merge diagram of the structural unit, (d) is an absorption spectrum of the absorber in the wavelength range of 800 nm to 2800 nm under TM wave and TE wave;

[0012] Figure 2 Results of the influence of different P values on the absorption performance of the absorber;

[0013] Figure 3 Results of the influence of different r1 values on the absorption performance of the absorber;

[0014] Figure 4 Results of the influence of different r2 values on the absorption performance of the absorber;

[0015] Figure 5 Results of the influence of different r3 values on the absorption performance of the absorber;

[0016] Figure 6 Results of the influence of different a values on the absorption performance of the absorber;

[0017] Figure 7 Results of the influence of different r4 values on the absorption performance of the absorber;

[0018] Figure 8 Results of the influence of different h1 values on the absorption performance of the absorber;

[0019] Figure 9 Results of the influence of different h2 values on the absorption performance of the absorber;

[0020] Figure 10 Results of the influence of different h3 values on the absorption performance of the absorber;

[0021] Figure 11 Results of the influence of missing the top layer Si3N4 regular hexagonal prism on the absorption performance of the absorber;

[0022] Figure 12 Results of the influence of missing the inlaid TiO2 regular hexagonal prism on the absorption performance of the absorber. DETAILED DESCRIPTION

[0023] The technical solutions of the present application will be further described below in combination with the drawings.

[0024] As Figure 1(a) to (c) show an absorber containing an inlay, which is composed of a plurality of absorption structure units arranged periodically, the absorption structure unit takes SiO2 as a substrate to facilitate compatibility with semiconductor process, the SiO2 substrate is provided with a Ti metal layer and two Si3N4 regular hexagonal prisms, and the inlay is arranged between the two Si3N4 regular hexagonal prisms; the inlay includes an outer layer of MgF2 regular hexagonal prism, a middle layer of Cr metal ring, and an inner layer of TiO2 regular hexagonal prism; the bottom area of the bottom layer of the two Si3N4 regular hexagonal prisms is larger than that of the top layer, the plane formed by the center line of the adjacent side of the top layer Si3N4 regular hexagonal prism and the vertical direction of the bottom layer Si3N4 regular hexagonal prism is perpendicular to the side of the bottom layer Si3N4 regular hexagonal prism, that is, the vertex of the bottom surface of the top layer Si3N4 regular hexagonal prism coincides with the midpoint of the top surface edge of the bottom layer Si3N4 regular hexagonal prism, the bottom edge of the MgF2 regular hexagonal prism is parallel to the bottom edge of the bottom layer Si3N4 regular hexagonal prism, and the bottom edge of the TiO2 regular hexagonal prism is parallel to the bottom edge of the top layer Si3N4 regular hexagonal prism. The SiO2 substrate and the Ti metal layer are a square structure with the same bottom surface, the side length of which is the same as the arrangement period P of the absorption structure unit, the height of the Ti metal layer is h1, the height of the bottom layer Si3N4 regular hexagonal prism is h2, the height of the top layer Si3N4 regular hexagonal prism is h3, the MgF2 regular hexagonal prism, the Cr metal ring and the TiO2 regular hexagonal prism of the inlay are all h2 in height, and the total height (h1+h2+h3) of the absorption structure unit is less than 3P. Figure 1 (d) The theoretical value of the absorption spectrum of the absorber in the wavelength range of 800 nm to 2800 nm under the incidence of TM and TE waves respectively, it can also be seen from the figure that it is almost not affected by the polarization of the incident wave in different directions, and has high absorption efficiency.

[0025] The structure period of the periodic absorber in the infrared waveband needs to be reduced to nanoscale, usually 200-500 nm, to meet the subwavelength condition and excite the required electromagnetic resonance (such as surface plasmon resonance, photonic localization, etc.). Through simulation experiments, the optimal parameter of P is near 280-320 nm. In order to obtain the influence of the change of array period P on the absorptivity of the absorber, the other simulation parameters are kept unchanged, the change range of P is set from 280 nm to 320 nm, the simulation step is 10 nm, and the obtained absorptivity curve is as follows Figure 2As shown, when P = 300 nm, high absorption rate and ultra-wideband absorption can be achieved; when P is small, the absorption efficiency is low and the effective absorption bandwidth is narrow; when P is large, although the absorption curve changes little, the average absorption rate decreases and the effective absorption bandwidth is also narrow. This is because when the period of the unit absorption structure is too large or too small, the resonance strength of the adjacent absorption structure unit period decreases, and the absorption rate decreases, so the period P of the absorption structure unit is 300 nm. On this basis, the influence of the change of other structural component sizes on the performance of the absorber is discussed.

[0026] To obtain the influence of the change of the half r1 of the diagonal distance of the hexagonal Si3N4 prism on the absorption rate of the absorber, the other simulation parameters are kept unchanged, the change range of r1 is set from 120 nm to 150 nm, the simulation step is 10 nm, and the obtained absorption rate curve is as shown in Figure 3 From the figure, it can be seen that r1 has a great influence on the absorption rate, and the absorption rate is best when r1 is 150 nm, which is half of the best array period P; when r1 is small, not only the absorption rate decreases greatly, but also the bandwidth is significantly narrowed; then r1 is not the bigger the better, when r1 exceeds 150 nm, the Si3N4 hexagonal prism will be larger than the period P, which will cause strong coupling or diffraction effect between the periodic absorber units, so that the absorption peak is shifted / split, the absorption bandwidth is narrowed, and at the same time, larger than P will affect the periodic arrangement of the absorption structure unit, and larger than P will increase the manufacturing difficulty and greatly reduce the manufacturing precision, affecting the application of the absorber, so the best parameter of r1 is 150 nm.

[0027] To obtain the influence of the change of the half r2 of the diagonal distance of the hexagonal MgF2 prism on the absorption rate of the absorber, the other simulation parameters are kept unchanged, the change range of r2 is set from 99 nm to 139 nm, the simulation step is 10 nm, and the obtained absorption rate curve is as shown in Figure 4It can be seen from the figure that the influence of r2 on the performance of the absorber is less than that of r1, the absorptivity of the absorber is the highest and the absorption bandwidth is the largest when r2 = 129 nm; when r2 is small, the absorption rate curve decreases to different degrees, and the absorption bandwidth also narrows to different degrees; when r2 is large, although the absorption rate in the range of 2000 nm to 2800 nm is not much different, but from the overall average absorption rate, it is lower than that when r2 = 129 nm. This is because when r2 = 129 nm, the MgF2 regular hexagonal prism is inscribed in the bottom layer Si3N4 regular hexagonal prism, which can ensure the uniform coupling of electromagnetic field / acoustic field between the absorption structure units, avoid energy leakage or local field strength being too high, and thus optimize the absorption efficiency; when they are not tangent, the gap between them will cause energy leakage or resonance frequency shift; then if they overlap with each other, it may cause strong coupling, destroy the impedance matching of the design, and affect the absorption rate and absorption bandwidth and stability. In order to make the absorber maintain high and stable absorption rate and wide absorption bandwidth, r2 is selected as 129 nm.

[0028] In order to obtain the influence of the change of the outer radius r3 of the embedded Cr metal ring on the absorption rate of the absorber, the other simulation parameters are kept unchanged, the change range of r3 is set to be from 92.5 nm to 132.5 nm, the simulation step is 10 nm, and the obtained absorption rate curve is as shown in Figure 5 It can be seen from the figure that the influence of r3 on the absorber is similar to that of r2; when r3 is small, the absorption rate curve decreases obviously, and the absorption bandwidth also narrows; when r3 is large, the average absorption rate decreases slightly, and the fluctuation of the absorption rate is large; when r3 is 112.5 nm, high absorption rate and ultra-wideband absorption can be considered. In order to obtain the influence of the change of the ring width a of the Cr metal ring on the absorption rate of the absorber, the other simulation parameters are kept unchanged, the change range of a is set to be from 2.5 nm to 22.5 nm, the simulation step is 5 nm, and the obtained absorption rate curve is as shown in Figure 6 It can be seen from the figure that when a is large, the absorption rate is small, and the absorption bandwidth is also narrow; when a is small, the change of a has little effect on the absorption rate and the bandwidth. Considering a = 12.5 nm and r3 = 112.5 nm, the Cr metal ring is inscribed in the MgF2 regular hexagonal prism at this time.

[0029] In order to obtain the influence of the change of the half of the diagonal line distance r4 of the bottom regular hexagon of the embedded TiO2 regular hexagonal prism on the absorption rate of the absorber, the other simulation parameters are kept unchanged, the change range of r4 is set to be from 80 nm to 110 nm, the simulation step is 10 nm, and the obtained absorption rate curve is as shown in Figure 7The simulation results are shown in FIG. 6. As can be seen from the figure, the influence of r4 on the absorber is higher than that of r2, r3 and a, and lower than that of r1; when the value of r4 is low, the absorption curve is obviously low; when the value of r4 gradually increases, the absorption curve obviously rises, the absorption rate increases and the absorption bandwidth also widens. When r4 increases to a certain value, the change of the influence on the absorption rate tends to be gentle. Considering the matching with the Cr metal ring, r4 is selected as 100 nm, and the TiO2 regular hexagonal prism is inscribed in the Cr metal ring.

[0030] In order to obtain the influence of the change of the height h1 of the Ti metal layer on the absorption rate of the absorber, other simulation parameters are kept unchanged, the change range of h1 is set to be from 230 nm to 270 nm, and the simulation step is 10 nm. The obtained absorption rate curve is shown in FIG. 7. Figure 8 As can be seen from the figure, the change of h1 has little influence on the absorption curve; the absorption rate is better when h1 is 250 nm and 270 nm within 1000 nm to 1600 nm, and the change of the two values has little influence on the absorption performance. In order to reduce the structure size of the absorber as much as possible, h1 = 250 nm is selected as the best structure parameter. When the size of the periodic absorption structure unit and the wavelength of the incident wave satisfy certain conditions, non-zero order diffraction phenomenon, i.e. high order diffraction, is generated, which significantly influences the performance of the absorber. However, when the size of the periodic absorption structure unit no longer satisfies the sub-wavelength and is greater than the incident wavelength, the absorption efficiency of the absorber decreases, the bandwidth narrows, and the stability and polarization dependence of the absorption efficiency are influenced.

[0031] In order to obtain the influence of the change of the height h2 of the bottom layer Si3N4 regular hexagonal prism and the inner embedded body on the absorption rate of the absorber, other simulation parameters are kept unchanged, the change range of h2 is set to be from 160 nm to 230 nm, and the simulation step is 10 nm. The obtained absorption rate curve is shown in FIG. 8. Figure 9 As can be seen from the figure, the influence of h2 on the absorption efficiency of the absorber is greater than that of h1; when h2 has a small value, the absorption bandwidth narrows; when h2 has a large value, although the absorption bandwidth increases, the average absorption rate decreases; when h2 = 180 nm, high absorption rate and ultra-wideband absorption can be considered. Considering the size of the absorber and preventing the overall height of the absorber from being greater than 3P, h2 = 180 nm is selected as the best structure parameter.

[0032] In order to obtain the influence of the change of the height h3 of the top layer Si3N4 regular hexagonal prism on the absorption rate of the absorber, other simulation parameters are kept unchanged, the change range of h3 is set to be from 120 nm to 160 nm, and the simulation step is 10 nm. The obtained absorption rate curve is shown in FIG. 9. Figure 10The simulation results are shown in FIG. 6. As can be seen from the figure, the change of h3 has little effect on the absorption efficiency of the absorber, and the absorption rate in the range of 1700 nm to 2800 nm does not change significantly; in the range of 800 nm to 1700 nm, the average absorption rate is the highest when h3 = 140 nm, and the h3 is taken as 140 nm as the best structural parameter.

[0033] In order to verify the influence of the top layer Si3N4 regular hexagonal prism on the absorption performance of the absorber, the simulation is carried out after removing the top layer Si3N4 regular hexagonal prism, and then compared with the best structure, the simulation results are shown in FIG. 7. Figure 11 As can be seen from the figure, the top layer Si3N4 regular hexagonal prism has a great influence on the absorption performance of the absorber, and the absorption rate is significantly reduced after removing the top layer Si3N4, the absorption bandwidth is narrowed, and the stability of the absorption efficiency is deteriorated, because the presence or absence of the top layer Si3N4 regular hexagonal prism will affect the matching degree of the relative impedance value of the absorber in the corresponding waveband and the relative impedance value of the free space, the refractive index of Si3N4 is between air and the lower layer material, the height of the top layer Si3N4 regular hexagonal prism is designed as λ / 4 optical thickness, which can significantly reduce the surface reflectivity and further improve the absorption efficiency; in addition, Si3N4 has moderate dielectric constant and low dielectric loss, which can adjust its dielectric properties by doping or combining other materials to enhance the electromagnetic wave absorption capacity, so Si3N4 is selected as the carrier of the embedded body, and the same material is used for both, which can also reduce the manufacturing difficulty.

[0034] In order to verify the influence of the embedded TiO2 regular hexagonal prism on the absorption performance of the absorber, the simulation is carried out after removing the TiO2 regular hexagonal prism, and then compared with the best structure, the simulation results are shown in FIG. 8. Figure 12 As can be seen from the figure, after removing the TiO2 regular hexagonal prism, the absorption bandwidth is significantly narrowed, and the average absorption rate is significantly reduced, which does not achieve the design goal of high absorption performance, and it can be seen that the embedded TiO2 regular hexagonal prism has a great influence on the absorption performance of the absorber, which is greater than that of removing the top layer Si3N4 regular hexagonal prism. Figure 6 It can be seen from the combination that the smaller the size of the TiO2 regular hexagonal prism is, the absorption efficiency is gradually reduced, which is because the change of the size of the TiO2 regular hexagonal prism leads to the imbalance of impedance matching, and then affects the absorption efficiency and bandwidth of the absorber.

[0035] In consideration of the above, the absorption structure unit of the absorber is arranged periodically with P=300nm, the half of the diagonal distance of the bottom layer Si3N4 regular hexagonal prism r1=1 / 2P, the half of the diagonal distance of the top layer Si3N4 regular hexagonal prism is equal to the half of the diagonal distance of the MgF2 regular hexagonal prism r2=112.5nm, the outer diameter of the Cr metal ring r3=100nm, the ring width of the Cr metal ring a=12.5nm, the half of the diagonal distance of the TiO2 regular hexagonal prism r4=100nm, that is, the vertex of the bottom surface of the top layer Si3N4 regular hexagonal prism coincides with the midpoint of the edge of the top surface of the bottom layer Si3N4 regular hexagonal prism, the outer layer MgF2 regular hexagonal prism of the inlay is inscribed in the bottom layer Si3N4 regular hexagonal prism, the Cr metal ring is inscribed in the MgF2 regular hexagonal prism, the TiO2 regular hexagonal prism is inscribed in the Cr metal ring, the total height of the Ti metal layer h1=250nm, the height of the bottom layer Si3N4 regular hexagonal prism h2=180nm, the height of the top layer Si3N4 regular hexagonal prism h3=140nm, and the absorption performance of the absorber is optimal. When the incident wavelength is from 800nm to 2800nm, the absorber covers from near-infrared 800nm to mid-infrared 2800nm, about 2000nm, and achieves an average absorption rate of 96.64% under TM wave, with a maximum absorption rate of 99.90%; under TE wave, it achieves an average absorption rate of 95.79%, with a maximum absorption rate of 99.86%, which is almost independent of polarization. In view of the key requirement of the solar heat absorber to have wide spectral response and high absorption efficiency, the new absorber proposed in the patent effectively suppresses the loss of radiant energy by optimizing the spectral selectivity characteristics. This innovative design provides a more optimal absorption solution for solar thermal photovoltaic (STPV) systems, concentrated solar power (CSP) and other renewable energy technologies, which has important significance for promoting the development of high-efficiency light-to-heat conversion technology.

Claims

1. An absorber comprising an inlay, comprising a plurality of absorbent structural units arranged periodically, characterized in that: The absorption structure unit includes a SiO2 substrate, a Ti metal layer, and two Si3N4 regular hexagonal prisms coaxially arranged from bottom to top, and an inlay coaxially arranged inside the bottom Si3N4 regular hexagonal prism; the inlay includes an outer layer of MgF2 regular hexagonal prisms, a middle layer of Cr metal rings, and an inner layer of TiO2 regular hexagonal prisms; the bottom area of ​​the two Si3N4 regular hexagonal prisms is larger than the bottom area of ​​the top layer, the surface formed by the edge of the top Si3N4 regular hexagonal prism and the center line of the adjacent side surface of the bottom Si3N4 regular hexagonal prism in the perpendicular direction is perpendicular to the side surface of the bottom Si3N4 regular hexagonal prism, the bottom edge of the MgF2 regular hexagonal prism is parallel to the bottom edge of the bottom Si3N4 regular hexagonal prism, and the bottom edge of the TiO2 regular hexagonal prism is parallel to the bottom edge of the top Si3N4 regular hexagonal prism.

2. The absorber comprising an inlay according to claim 1, wherein: The inlay is as high as the bottom Si3N4 regular hexagonal prism.

3. The absorber comprising an inlay according to claim 2, wherein: The SiO2 substrate and the Ti metal layer are cube structures with the same bottom surface, and the side length is the same as the arrangement period P of the absorption structure units.

4. The absorber comprising an inlay according to claim 3, wherein: The arrangement period P is 280-320 nm, and the total height of the structural unit is less than 3P.

5. The absorber comprising an inlay according to claim 4, wherein: The arrangement period P=300nm.

6. The absorber comprising an inlay according to claim 4 or 5, characterized in that: The half of the diagonal distance of the regular hexagon of the bottom surface of the Si3N4 regular hexagonal prism of the bottom layer r1 is 120-150 nm, the half of the diagonal distance of the regular hexagon of the bottom surface of the Si3N4 regular hexagonal prism of the top layer Si3N4 regular hexagonal prism is equal to the half of the diagonal distance of the regular hexagon of the bottom surface of the MgF2 regular hexagonal prism r2 is 99-139 nm, the outer diameter of the Cr metal ring r3 is 92.5-132.5 nm, the ring width of the Cr metal ring a is 2.5-22.5 nm, and the half of the diagonal distance of the regular hexagon of the bottom surface of the TiO2 regular hexagonal prism r4 is 80-110 nm.

7. The absorber comprising an inlay according to claim 6, wherein: The half of the diagonal distance between the bottom surface of the regular hexagonal column of the Si3N4 regular hexagon is r1=150nm, the half of the diagonal distance between the bottom surface of the regular hexagonal column of the top layer Si3N4 regular hexagon is equal to the half of the diagonal distance between the bottom surface of the regular hexagonal column of the MgF2 regular hexagon is r2=112.5nm, the outer diameter of the Cr metal ring is r3=100nm, the ring width of the Cr metal ring is a=12.5nm, and the half of the diagonal distance between the bottom surface of the regular hexagonal column of the TiO2 regular hexagon is r4=100nm.

8. The absorber comprising an inlay according to claim 6, wherein: The total height h1 of the Ti metal layer is 230-270 nm, the height h2 of the inlay and the bottom Si3N4 regular hexagonal prism is 160-230 nm, and the height h3 of the top Si3N4 regular hexagonal prism is 120-160 nm.

9. The absorber comprising an inlay according to claim 7 or 8, characterized in that: The total height h1 of the Ti metal layer is 250 nm, the height h2 of the inlay and the bottom Si3N4 regular hexagonal prism is 180 nm, and the height h3 of the top Si3N4 regular hexagonal prism is 140 nm.

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