CN113325495A

CN113325495A - Ultra-wideband super-surface perfect absorber based on triple Mie resonance

Info

Publication number: CN113325495A
Application number: CN202110421080.8A
Authority: CN
Inventors: 陈海涛; 钱沁宇; 樊莉; 王钦华; 丁强
Original assignee: Yangzhou University
Current assignee: Yangzhou University
Priority date: 2021-04-19
Filing date: 2021-04-19
Publication date: 2021-08-31
Anticipated expiration: 2041-04-19
Also published as: CN113325495B

Abstract

The invention provides an ultra-wideband super-surface perfect absorber based on triple Mie resonance, which comprises a substrate, wherein a transition layer is arranged on the substrate, a plurality of uniformly distributed round holes are arranged on the transition layer, a first layer, a second layer and a third layer which are the same as the transition layer in shape and height are arranged above the transition layer, and round holes corresponding to the round holes in the transition layer are formed in the first layer, the second layer and the third layer; a first nano-column, a second nano-column and a third nano-column are sequentially arranged in the round holes of the transition layer, the first layer and the second layer; the ultra-wideband perfect absorber with the super-surface structure has a good absorption effect, and has important application prospects in photovoltaic, radiation cooling, optical detection, stealth and mechanical manipulation.

Description

Ultra-wideband super-surface perfect absorber based on triple Mie resonance

Technical Field

The invention relates to the technical field of electromagnetic metamaterials, in particular to an ultra-wideband super-surface perfect absorber based on triple Mie resonance.

Background

In recent decades, electromagnetic metamaterials have rapidly become hot spots for domestic and foreign research. The electromagnetic metamaterial is an artificial material which is unnatural and has special properties. By varying the parameters of the cell configuration it is possible to obtain physical properties, such as left-handed properties, which are not found in natural materials. The electromagnetic metamaterial has good application prospects in the aspects of high directional antennas, radars, focused micro-beams, electromagnetic wave stealth, satellite communication and the like. The difference of the metamaterial unit structure determines the difference of the performance, such as changing the dielectric constant or the magnetic permeability of the metamaterial, and the purpose of distorting electromagnetic waves can be achieved. Among the best known metamaterials are left-handed materials, which have negative dielectric constants and negative magnetic permeabilities. By using these characteristics, a perfect lens can be obtained or the inverse Doppler effect can be achieved.

When the incident light irradiates the surface of the absorber, the incident light can be absorbed into the absorber to the maximum extent instead of being reflected out, and the absorber can completely consume the energy of the light absorbed into the absorber, so that the absorber can perfectly absorb the light. We can obtain this incredible perfect absorber by changing the structural parameters of the metamaterial. With the gradual development of science and technology, a novel metamaterial absorber has become a great research focus.

Disclosure of Invention

This section is for the purpose of summarizing some aspects of embodiments of the invention and to briefly introduce some preferred embodiments. In this section, as well as in the abstract and the title of the invention of this application, simplifications or omissions may be made to avoid obscuring the purpose of the section, the abstract and the title, and such simplifications or omissions are not intended to limit the scope of the invention.

Therefore, the technical problem to be solved by the invention is to overcome the defects of the prior art that the absorption range of the metamaterial absorber is not wide enough and the absorption effect is not good, so that the ultra-wideband super-surface perfect absorber based on the triple mie resonance is provided.

In order to solve the technical problems, the invention provides the following technical scheme: the ultra-wideband super-surface perfect absorber based on triple Mie resonance comprises a substrate, wherein a transition layer is arranged on the substrate, a plurality of uniformly distributed round holes are formed in the transition layer, a first layer, a second layer and a third layer which are the same as the transition layer in shape and height are arranged above the transition layer, and round holes corresponding to the round holes in the transition layer are formed in the first layer, the second layer and the third layer; and a first nano column, a second nano column and a third nano column are sequentially arranged in the round holes of the transition layer, the first layer and the second layer.

As a preferable scheme of the ultra-wideband super-surface perfect absorber based on the triple mie resonance, the ultra-wideband super-surface perfect absorber based on the triple mie resonance comprises the following steps: the substrate is made of silicon dioxide, the transition layer is made of photoresist, the first layer is made of silicon, the second layer is made of chromium, and the third layer is made of aluminum.

As a preferable scheme of the ultra-wideband super-surface perfect absorber based on the triple mie resonance, the ultra-wideband super-surface perfect absorber based on the triple mie resonance comprises the following steps: the first nano-pillar is made of silicon, the second nano-pillar is made of chromium, and the third nano-pillar is made of aluminum.

As a preferable scheme of the ultra-wideband super-surface perfect absorber based on the triple mie resonance, the ultra-wideband super-surface perfect absorber based on the triple mie resonance comprises the following steps: the diameter of the round hole is 160nm, the height of the round hole is 71nm, the round holes are arranged in an array mode in the transverse direction and the longitudinal direction respectively, and the array period is 250 nm.

As a preferable scheme of the ultra-wideband super-surface perfect absorber based on the triple mie resonance, the ultra-wideband super-surface perfect absorber based on the triple mie resonance comprises the following steps: and incident light is arranged above the third layer, and the angle range of the incident light is set to be 0-70 degrees.

As a preferable scheme of the ultra-wideband super-surface perfect absorber based on the triple mie resonance, the ultra-wideband super-surface perfect absorber based on the triple mie resonance comprises the following steps: the wavelength range of the incident light is set to 400nm-1800 nm.

As a preferable scheme of the ultra-wideband super-surface perfect absorber based on the triple mie resonance, the ultra-wideband super-surface perfect absorber based on the triple mie resonance comprises the following steps: and the absorption performance is calculated and optimized by adopting a time domain finite difference method.

As a preferable scheme of the ultra-wideband super-surface perfect absorber based on the triple mie resonance, the ultra-wideband super-surface perfect absorber based on the triple mie resonance comprises the following steps: the maximum absorbance is 0.998 at 550 nm.

As a preferable scheme of the ultra-wideband super-surface perfect absorber based on the triple mie resonance, the ultra-wideband super-surface perfect absorber based on the triple mie resonance comprises the following steps: the average absorption rate of the incident light at the wavelength band of 400nm-1800nm is 0.970 when the incident light angle is 0 DEG, and the average absorption rates of the incident light at the incident light angles of 60 DEG and 70 DEG are 0.931 and 0.851 respectively.

The invention has the beneficial effects that: the perfect absorber provided by the invention can be manufactured by a double-beam interference photoetching technology and a subsequent sputtering coating deposition process, and is beneficial to large-area manufacture; the absorber has an average absorption rate of 0.961 in the wavelength range of 400nm to 1800nm, and the absorption effect is good even if the incident angle reaches 70 degrees; the ultra-wideband perfect absorber with the super-surface structure has important application prospects in photovoltaics, radiation cooling, light detection, stealth and mechanical manipulation.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise. Wherein:

FIG. 1 is a schematic view of a partial structure of a perfect absorber provided by the present invention;

FIG. 2 is a schematic longitudinal cross-sectional view of a perfect absorber provided by the present invention;

FIG. 3 is a theoretical absorption spectrum of a perfect absorber provided by the present invention at different incident angles;

FIG. 4 is an absorption spectrum of (a) embedding silicon pillars only on the transition layer, (b) embedding chromium pillars only on the transition layer, (c) embedding silicon and chromium sequentially in the transition layer and the first layer, (d) a perfect absorber provided by the present invention;

FIGS. 5(a), (c) and (e) are side views of the electric field in the xz plane cut at wavelengths of 400nm, 890nm and 1590nm along the diameter of the nanopillar; (b) (d) and (f) are top views of the electric field cut along the center of the Si, Cr and Al nanopillars, respectively, in the xy plane;

FIG. 6(a) is a process for the preparation of a perfect absorber; (b) scanning electron microscope photo of transition layer structure; (c) is a photograph of the absorption spectrum measured at different incident angles of the fabricated absorber filter and a sample in a natural white light environment;

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, but the present invention may be practiced in other ways than those specifically described and will be readily apparent to those of ordinary skill in the art without departing from the spirit of the present invention, and therefore the present invention is not limited to the specific embodiments disclosed below.

Example 1

The present embodiment provides an ultra-wideband super-surface perfect absorber (MSPA) based on triple-mie resonance, as shown in FIGS. 1-2, comprising

The structure comprises a substrate 101, wherein a transition layer 102 is arranged on the substrate 101, a plurality of uniformly distributed round holes 102b are formed in the transition layer 102, the round holes 102b are respectively arranged in an array mode along the transverse direction and the longitudinal direction, a first layer 103, a second layer 104 and a third layer 105 which are the same as the transition layer 102 in shape and height are arranged above the transition layer 102, and round holes 102b corresponding to the round holes 102b in the transition layer 102 are formed in the first layer 103, the second layer 104 and the third layer 105; the round holes 102b of the transition layer 102, the first layer 103 and the second layer 104 are sequentially provided with a first nano-pillar 102a, a second nano-pillar 103a and a third nano-pillar 104 a.

The substrate 101 is made of silicon dioxide, the transition layer 102 is made of Photoresist (PMMA), the first layer 103 is made of silicon, the second layer 104 is made of chromium, and the third layer 105 is made of aluminum; the first nano-pillar 102a is made of silicon, the second nano-pillar 103a is made of chromium, and the third nano-pillar 104a is made of aluminum.

In this embodiment, the diameter and height of the circular hole 102b are set as d and h, respectively, the period of the array is p, and then three layers of silicon, chromium and aluminum with the same height h are sequentially deposited on the whole structure, so that three groups of nano-pillars are embedded in the circular hole 102 b. The absorption performance of a theoretically perfect absorber is calculated and optimized using the time-domain finite difference method, with the parameters optimized to d 160nm, h 71nm and p 250nm, with the incident light disposed above the third layer 105, with the incident light angle range set at 0-70 °, and the incident light wavelength range set at 400-1800 nm. FIG. 3 shows theoretical absorption spectra at different angles of incidence, and it can be seen that the absorption at a wavelength of 550nm is 0.998 at maximum, and the average absorption at normal incidence at a wavelength band of 400nm to 1800nm is 0.970; the proposed perfect absorber also shows excellent angular characteristics when the incident angle is increased to 60 ° and 70 °, with the average absorption still being as high as 0.931 and 0.851, respectively.

Triple-coupled triple-mie resonances of the three sets of nano-pillars cause high absorption over a wide wavelength range. FIG. 4(a) shows an absorption spectrum of a Si pillar array having a height of 71nm and a diameter of 160nm embedded in PMMA on a SiO2 substrate, and it can be seen from FIG. 4(a) that the Si pillar array shows good absorption performance at short wavelengths, but the absorption drops sharply as the wavelength increases. Fig. 4(b) is a comparison of absorption spectra of a Cr pillar array with a height of 71nm and a diameter of 160nm embedded in PMMA on a SiO2 substrate, and although the Cr pillar array has a higher absorbance at long wavelengths as shown in fig. 4(b), its absorbance at short wavelengths is lower than that of a Si pillar array. The nanopillar array can achieve very high absorption at the resonance wavelength, but it decreases away from the resonance wavelength due to the three mie resonances created by the structure. For example, the absorption in FIG. 4(b) is as high as 0.990 at a wavelength of 595nm, but the absorption decreases significantly when leaving the resonance wavelength. By coupling the triple mie resonances induced by the two nanopillar arrays, high absorption can be achieved in a wider wavelength band, fig. 4(c) the absorption spectra of the PMMA embedded Si and Si embedded Cr pillar arrays on the SiO2 substrate, as shown in fig. 4(c), the combined Si and Cr pillar arrays work well in the visible band but do not perform well in the IR band. To obtain higher absorption in the infrared band, an array of Al pillars was added to the structure. FIG. 4(d) absorption spectra of the perfect absorbers proposed in this example, each having a height of 71nm and a diameter of 160nm, it can be seen from FIG. 4(d) that the absorption in the IR band is much higher than the structure without Al pillar array, and the average absorption in the band of 400nm to 1800nm is very high, 0.970. It is clear that high bandwidth absorption is achieved by exciting the triple mie resonance of the three sets of nano-pillars.

To better understand the proposed triple-coupled triple-mie resonance of the MSPA internal nanopillars, fig. 3 shows the electric field inside the structure. As shown in fig. 5(a), there is a strong electric field around or inside the Si column at 400nm wavelength, indicating that most of the light is absorbed by the Si structure, which is consistent with the results of fig. 4 (a). As is clear from fig. 5(b), the electric field is strongly bound to the Si column, and the resonance excitation characteristic is shown as a triplet mie resonance. When the absorption of the silicon structure is low at 890nm wavelength, as shown in fig. 5(c), the transmitted light of the first layer 103 is further absorbed by the Cr structure, which is consistent with the result of fig. 4 (b). The electric field inside and around the Cr columns in fig. 5(d) is also consistent with the theoretical prediction of Mie resonance. Fig. 5(e) shows the electric field inside the proposed MSPA at 1590nm wavelength, where the incident light cannot be completely absorbed by the Si and Cr structure. It can be seen that the Al structure prevents the proposed MSPA from light transmission, which is predicted by fig. 4 (c). Fig. 5(f) shows the electric field in the third layer 105 of the proposed MSPA, which also shows the mie resonance properties of the excited resonance. In combination with the proposed Si, Cr and Al posts in the MSPA, the reflection of the device can be greatly reduced due to the triple-coupled triple-mie resonance of the integrated triple-layer pattern, as shown in fig. 4 (d). The Al structure also inhibits transmission since the thickness of Al is sufficient to prevent the passage of incident light, particularly in the IR range.

Example 2

This embodiment differs from the previous embodiment in that, as shown in figure 6,

to verify and prove perfect absorption performance through experimentation, the proposed MSPA can be fabricated using well-designed two-beam interference lithography and then by sputter coating deposition, as shown in fig. 6 (a). First, a SiO2 substrate was prepared by ultrasonic cleaning in acetone, and a PMMA layer of about 100nm was spin-coated onto the substrate; then, forming PMMA into a required profile by using an ultraviolet double-beam interference photoetching technology with an optimal exposure and development process; finally, the Si, Cr and Al coatings were deposited by successive ion sputtering. A picture of PMMA produced by a scanning electron microscope is shown in fig. 6 (b). The diameter of the circular hole 102b is 160nm and the period is 250nm, very close to the design parameters. The measured absorbance a of the manufactured MSPA is shown in fig. 6(c) by determining the transmission T and reflectance R of the manufactured MSPA from a step size of 400nm of 20nm to 1800nm by operating in the whole wavelength band using a supercontinuum laser model of Fianium SC450 and a detector model of Thorlabs PAX5710IR1-T, where the absorbance is calculated from a ═ 1-T-R (T is the transmission and R is the reflectance). It can be seen that the absorption in the entire wavelength band is very high even at large angles of incidence. The average absorptions at incident angles of 0 °, 30 °, 50 ° and 70 ° were 0.961, 0.956, 0.939 and 0.851, respectively, close to the theoretical results (0.970, 0.969, 0.957 and 0.871, respectively). Visual properties as also shown in the photograph in fig. 6(c), it can be seen that a "dark region" is observed in the center of the sample. In contrast, a "bright area" without any structure around the black area indicates strong reflection of natural light.

Thus, in this example, we have both theoretically and experimentally demonstrated a Mie resonance based ultra-wideband MSPA with a theoretical average absorbance of 0.970 and an experimental average absorbance of 0.961 over the wavelength range of 400nm to 1800 nm. The parameters given are the result of theoretical optimization, and the error range allowed in practice is: d is 160 + -15 nm, h is 71 + -12 nm, and p is 250 + -20 nm. The proposed MSPA is manufactured by a well-designed two-beam interference lithography technique followed by a sputter coating deposition process, which has the advantage of large area and ease of manufacture. The MSPA provides a proposal for efficiently designing and manufacturing a novel ultra-wideband perfect absorber, which has important application prospects in the aspects of photovoltaic, radiation cooling, optical detection, stealth and mechanical manipulation.

It is important to note that the construction and arrangement of the present application as shown in the various exemplary embodiments is illustrative only. Although only a few embodiments have been described in detail in this disclosure, those skilled in the art who review this disclosure will readily appreciate that many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters (e.g., temperatures, pressures, etc.), mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter recited in this application. For example, elements shown as integrally formed may be constructed of multiple parts or elements, the position of elements may be reversed or otherwise varied, and the nature or number of discrete elements or positions may be altered or varied. Accordingly, all such modifications are intended to be included within the scope of this invention. The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. In the claims, any means-plus-function clause is intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures. Other substitutions, modifications, changes and omissions may be made in the design, operating conditions and arrangement of the exemplary embodiments without departing from the scope of the present inventions. Therefore, the present invention is not limited to a particular embodiment, but extends to various modifications that nevertheless fall within the scope of the appended claims.

Moreover, in an effort to provide a concise description of the exemplary embodiments, all features of an actual implementation may not be described (i.e., those unrelated to the presently contemplated best mode of carrying out the invention, or those unrelated to enabling the invention).

It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions may be made. Such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure, without undue experimentation.

It should be noted that the above-mentioned embodiments are only for illustrating the technical solutions of the present invention and not for limiting, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, which should be covered by the claims of the present invention.

Claims

1. The ultra-wideband super-surface perfect absorber based on the triple Mie resonance is characterized in that: comprises the steps of (a) preparing a mixture of a plurality of raw materials,

the light-emitting diode comprises a substrate (101), wherein a transition layer (102) is arranged on the substrate (101), a plurality of uniformly distributed round holes (102b) are formed in the transition layer (102), a first layer (103), a second layer (104) and a third layer (105) which are the same as the transition layer (102) in shape and height are arranged above the transition layer (102), and round holes (102b) corresponding to the round holes (102b) in the transition layer (102) in position are formed in the first layer (103), the second layer (104) and the third layer (105);

a first nano-pillar (102a), a second nano-pillar (103a) and a third nano-pillar (104a) are sequentially arranged in the round holes (102b) of the transition layer (102), the first layer (103) and the second layer (104).

2. The ultra-wideband super-surface perfect absorber based on triple mie resonance as claimed in claim 1, wherein: the substrate (101) is made of silicon dioxide, the transition layer (102) is made of photoresist, the first layer (103) is made of silicon, the second layer (104) is made of chromium, and the third layer (105) is made of aluminum.

3. The ultra-wideband super-surface perfect absorber based on triple mie resonance as claimed in claim 2, wherein: the first nano-pillar (102a) is made of silicon, the second nano-pillar (103a) is made of chromium, and the third nano-pillar (104a) is made of aluminum.

4. The ultra-wideband super-surface perfect absorber based on triple mie resonance as claimed in claim 3, wherein: the diameter of the round holes (102b) is 160nm, the height of the round holes (102b) is 71nm, the round holes (102b) are arranged in an array mode in the transverse direction and the longitudinal direction respectively, and the array period is 250 nm.

5. The ultra-wideband super-surface perfect absorber based on triple mie resonance as claimed in claim 4, wherein: incident light is arranged above the third layer (105), and the incident light angle range is set to be 0-70 degrees.

6. The ultra-wideband super-surface perfect absorber based on triple mie resonance as claimed in claim 5, wherein: the wavelength range of the incident light is set to 400nm-1800 nm.

7. The ultra-wideband super-surface perfect absorber based on triple mie resonance as claimed in claim 6, wherein: and the absorption performance is calculated and optimized by adopting a time domain finite difference method.

8. The ultra-wideband super-surface perfect absorber based on triple mie resonance as claimed in claim 7, wherein: the maximum absorbance is 0.998 at 550 nm.

9. The ultra-wideband super-surface perfect absorber based on triple mie resonance as claimed in claim 8, wherein: the average absorption rate of the incident light at the wavelength band of 400nm-1800nm is 0.970 when the incident light angle is 0 DEG, and the average absorption rates of the incident light at the incident light angles of 60 DEG and 70 DEG are 0.931 and 0.851 respectively.