CN110376667A - A kind of broadband electromagnetic wave absorber and preparation method thereof based on refractory material - Google Patents

Abstract

The present invention provides a kind of broadband electromagnetic wave absorber and preparation method thereof based on refractory material.The broadband electromagnetic wave absorber is successively made of the three-decker of the metal nano ring of smooth metallic diaphragm, the dielectric nano-rings of division and division from bottom to top.Metal therein can be the refractory materials such as titanium, nickel, chromium or tungsten metal.Present invention process preparation it is simple mature, it can be achieved that large area the manufacturing.The characteristics of absorber of the invention under complicated electromagnetic field environment there is broadband perfection to absorb, thermal stability.

Description

A kind of broadband electromagnetic wave absorber based on refractory material and preparation method thereof

technical field

The invention relates to the fields of materials science and energy, in particular to a broad-band electromagnetic wave absorber based on refractory materials and a preparation method thereof.

Background technique

The broadband electromagnetic wave absorber is one of the necessary devices to realize the efficient absorption of solar energy spectrum and broadband photodetection. Absorption or capture phenomenon.

Since the metamaterial absorber was reported in 2008, there has been a new upsurge in the international academic community. Broadband absorbers have promising applications in solar cells, thermal radiation, and imaging devices. So far, great progress has been made in the design of absorbers with excellent absorption properties. Many different types of absorbers have been proposed, including single-band, dual-band, multi-band and broadband absorbers. The metamaterial absorber is mainly composed of a metal-dielectric-metal three-layer structure. The performance of the absorber is not only determined by the material itself, but also closely related to the shape, size, arrangement and structural combination of the absorber material. The bottom metal layer is to prevent electromagnetic transmission (ie, the transmittance is 0), and the top metal structure is to match the absorber impedance to suppress reflection (ie, the reflectivity is close to 0). Therefore, according to the absorptivity formula A=1-R-T (wherein A represents the absorptivity, R represents the reflectivity, and T represents the transmittance), a perfect absorption with an absorptivity close to 100% can be obtained. Some existing broadband absorbers tend to absorb only one resonance wavelength, and the absorption band is narrow. In addition, these absorber systems suffer from some drawbacks, such as narrow absorption bandwidth, low absorption efficiency, complex structure, the need to use noble metal materials, and poor thermal stability.

Therefore, the design and realization of perfect absorption in a wide-band range only rely on a metal-dielectric composite system that is simple and easy to operate and can be produced in a large-area process.

SUMMARY OF THE INVENTION

In order to solve the defects of the absorber mentioned in the background art, the present invention provides a broadband electromagnetic wave absorber based on a refractory material and a preparation method thereof.

A kind of broadband electromagnetic wave absorber based on refractory material of the present invention comprises:

Flat metal film;

The split dielectric nanorings arrayed on the metal film, the splitting dielectric nanorings refer to that there are several gaps on the dielectric nanorings;

The split metal nanorings disposed on the split dielectric nanorings refer to the presence of several gaps on the metal nanorings.

Further, the split dielectric nanoring includes four uniformly distributed gaps, and the split metallic nanoring includes four uniformly distributed gaps.

Further, the thickness of the flat metal film is more than 150 nanometers, and the material of the flat metal film is titanium, nickel, chromium or tungsten.

Further, the thickness of the split dielectric nano-ring is 1-300 nanometers, and the material of the split dielectric nano-ring is silicon dioxide, aluminum oxide or magnesium fluoride.

Further, the thickness of the split metal nanoring is 1-300 nanometers, and the material of the split metal nanoring is titanium, nickel, chromium or tungsten.

Further, the inner and outer diameters of the split dielectric nanorings and the split metal nanorings are consistent, with an inner diameter of 1-300 nanometers and an outer diameter of 300-800 nanometers.

Further, the period of the array is greater than or equal to the outer diameter of the split dielectric nanorings, so that the split nanorings remain non-overlapping.

The above-mentioned preparation method of the broadband electromagnetic wave absorber based on refractory material, comprises the following steps:

(1) Provide a flat substrate;

(2) depositing a metal film layer of a specific thickness on the substrate;

(3) depositing a dielectric film layer of a specific thickness on the metal film layer obtained in step (2);

(4) depositing a metal film layer of a specific thickness on the dielectric film layer obtained in step (3);

(5) using maskless electron beam etching and focused ion beam etching technology to etch to obtain an array structure of split metal nanorings and an array structure of split dielectric nanorings;

(6) Washing with absolute ethanol and acetone to obtain a broadband electromagnetic wave absorber based on refractory materials.

Further, the substrate is quartz, glass, silicon wafer or organic film.

Further, the deposition method includes one or a combination of magnetron sputtering, vacuum coating, metal thermal evaporation coating, laser pulse deposition, chemical plating, atomic layer deposition, and electrochemical methods. method.

Beneficial effects of the present invention:

1. The materials used in the entire electromagnetic wave absorber have the effect of high temperature resistance. The melting points of silicon dioxide, aluminum oxide, magnesium fluoride, titanium, nickel, chromium, and tungsten are 1650°C, 2054°C, 1248°C, 1668°C, 1445°C, 1907°C, and 3422°C, so the electromagnetic wave absorber has thermal stability against high temperature, which can effectively avoid the problems that the perfect light absorber based on the conventional noble metal particle array or multi-metal resonance array composite structure cannot overcome. Intrinsic metal ohmic losses, thermal effects and thermal instability;

2. By using the strong electromagnetic resonance mode and wide-band resonance absorption characteristics of refractory metal materials, perfect absorption in the near-infrared to mid-infrared band is achieved;

3. Based on the periodic arrangement of the split metal/dielectric nanorings, it can generate plasmon resonance modes in multiple frequency ranges, and then obtain the perfect absorption characteristics of wide-band electromagnetic waves;

4. The metal materials used are rich in refractory materials on the earth, with low cost and wide application prospects in the fields of solar cells, thermal radiation, stealth, and infrared imaging;

5. To achieve a more efficient solar energy absorption response, under the irradiation of incident light, that is, sunlight, the average absorption efficiency of 1234-3660 nanometers in the solar light band can reach an average absorption efficiency of more than 96.2%, so as to achieve efficient absorption of sunlight. ;

6. The absorber has a simple structure, is easy to prepare, simplifies the experimental preparation process, saves manpower and material resources, is easy to popularize and produce in practice, and has high practical value.

Description of drawings

The present invention will be further described in detail below with reference to the accompanying drawings.

FIG. 1 is a schematic structural diagram of a broadband electromagnetic wave absorber based on a refractory material of the present invention.

2 is an absorption spectrum diagram of a broadband electromagnetic wave absorber based on a refractory material in Example 1 of the present invention.

3 is the absorption spectrum diagram corresponding to the top layer of the refractory-based broadband electromagnetic wave absorber in Example 2-4 of the present invention with split chromium nanorings with thickness (h) of 45, 65, and 85 nanometers.

4 is the absorption spectrum diagram corresponding to the middle layer of the refractory material-based broadband electromagnetic wave absorber in the embodiment 5-7 of the present invention is a split silicon dioxide nanoring, the thickness (t) of which is 190, 210, and 230 nanometers.

5 is an absorption spectrum diagram corresponding to the inner diameters (r) of the nanorings split by the refractory material-based broadband electromagnetic wave absorber in Examples 8-10 of the present invention at 115, 135, and 155 nanometers.

6 is an absorption spectrum diagram corresponding to the nano-ring gaps (d) split by the refractory material-based broadband electromagnetic wave absorber in Examples 11-13 of the present invention at 25, 45, and 65 nanometers.

7 is a schematic structural diagram of a broadband electromagnetic wave absorber based on a refractory material according to Embodiment 14 of the present invention.

8 is an absorption spectrum diagram of a broadband electromagnetic wave absorber based on a refractory material in Example 15 of the present invention.

Detailed ways

As shown in FIG. 1 , a broad-band optical electromagnetic wave absorber based on refractory material of the present invention is composed of a flat metal film 1, a split dielectric nano-ring 2 and a split metal nano-ring 3 connected from bottom to top in sequence. to make. Among them, the split dielectric nanorings and the split metallic nanorings are arrayed periodically. Each split dielectric nanoring includes four uniformly distributed gaps, and each split metallic nanoring includes four uniformly distributed gaps.

The refractory-based broadband electromagnetic wave absorber can be prepared according to the following steps:

(1) Clean the flat substrate with the configured cleaning solution, then rinse it with deionized water, dry it with nitrogen, and fix it in the deposition chamber;

(2) depositing a metal film layer of a specific thickness on the substrate;

(3) depositing a dielectric film layer of a specific thickness on the metal film layer obtained in step (2);

(4) depositing a metal film layer of a specific thickness on the dielectric film layer obtained in step (3);

(5) using maskless electron beam etching and focused ion beam etching technology to etch to obtain an array structure of split metal nanorings and an array structure of split dielectric nanorings;

(6) Washing with absolute ethanol and acetone to obtain a broadband electromagnetic wave absorber based on refractory materials.

Specifically, the substrate may be quartz, glass, silicon wafer or organic film. The deposition methods include magnetron sputtering, vacuum coating, metal thermal evaporation coating, laser pulse deposition, electroless plating, atomic layer deposition, and electrochemical methods, or a combination of several methods.

Example 1:

A method for preparing a broadband optical electromagnetic wave absorber based on a refractory material in this embodiment: first, on the substrate silica glass sheet, a physical vacuum coating method is used to sequentially deposit a layer of chromium film with a thickness of 150 nanometers, a layer of thickness A silicon dioxide film with a thickness of 210 nm and a chromium film with a thickness of 65 nm; secondly, the split chromium/silicon dioxide nanorings were prepared by electron beam etching technology on the top chromium film and the middle silicon dioxide film as a period The array period (P) is 400 nm; the inner radius (r) of the split nanorings is 135 nm, and the outer radius (R) is 200 nm; the thickness of the flat metal film (a) is 150 nm, and the split The thickness (t) of the silica nanorings is 210 nm, and the thickness (h) of the split chromium nanorings is 65 nm; the gaps (d) of the split nanorings are both 45 nm.

The broadband optical electromagnetic wave absorber based on the refractory material of this embodiment is tested, and the absorption spectrum as shown in FIG. 2 can be obtained. As can be seen from Figure 2, from the near-infrared to mid-infrared range with wavelengths from 1234 nm to 3660 nm, the absorber achieves a strong absorption response with absorptivity greater than 90%, and the absorption broadband is 2426 nm, with an average absorption rate as high as 96.2% .

Example 2:

In the broadband optical electromagnetic wave absorber based on refractory material in this embodiment, the thickness of the split chromium nanoring on the top layer is 45 nanometers, and other parameters are the same as those in specific embodiment 1. The corresponding absorption spectrum as shown in Figure 3 can be obtained.

Example 3:

In the broadband optical electromagnetic wave absorber based on refractory material in this embodiment, the thickness of the split chromium nanoring on the top layer is 65 nanometers, and other parameters are the same as those in specific embodiment 1. The corresponding absorption spectrum as shown in Figure 3 can be obtained. When the thickness of the Cr nanoring is 65 nm, the spectral broadband of the absorber whose absorption rate is greater than 90% reaches 2426 nm, and the corresponding absorption spectrum ranges from 1234 nm to 3660 nm.

Example 4:

In the broadband optical electromagnetic wave absorber based on refractory material in this embodiment, the thickness of the split chromium nanoring on the top layer is 85 nanometers, and other parameters are the same as those in specific embodiment 1. The corresponding absorption spectrum as shown in Figure 3 can be obtained.

Example 5:

In the broadband optical electromagnetic wave absorber based on refractory material in this embodiment, the thickness of the silicon dioxide nano-ring split in the middle layer is 190 nanometers, and other parameters are the same as those in specific embodiment 1. The corresponding absorption spectrum as shown in Figure 4 can be obtained.

Example 6:

In the broadband optical electromagnetic wave absorber based on refractory material in this embodiment, the thickness of the silicon dioxide nanoring split in the middle layer is 210 nanometers, and other parameters are the same as those in specific embodiment 1. The corresponding absorption spectrum as shown in Figure 4 can be obtained. The absorber works best when the thickness of the split silica nanorings is 210 nm.

Example 7:

In the broadband optical electromagnetic wave absorber based on refractory material in this embodiment, the thickness of the silicon dioxide nanoring split in the middle layer is 230 nanometers, and other parameters are the same as those in specific embodiment 1. The corresponding absorption spectrum as shown in Figure 4 can be obtained.

Example 8:

In the broadband optical electromagnetic wave absorber based on refractory material in this embodiment, the inner radius of the silicon dioxide nano-ring split by the middle layer is 115 nm, and other parameters are the same as those in the specific embodiment 1. The corresponding absorption spectrum as shown in Figure 5 can be obtained.

Example 9:

In the broadband optical electromagnetic wave absorber based on refractory material in this embodiment, the inner radius of the silicon dioxide nano-ring split in the middle layer is 135 nm, and other parameters are the same as those in specific embodiment 1. The corresponding absorption spectrum as shown in Figure 5 can be obtained. When the inner radius is 135 nm, the absorption broadband of the absorber with absorption rate greater than 90% is the widest.

Example 10:

In the broadband optical electromagnetic wave absorber based on refractory material in this embodiment, the inner radius of the silicon dioxide nano-ring split by the middle layer is 155 nm, and other parameters are the same as those in specific embodiment 1. The corresponding absorption spectrum as shown in Figure 5 can be obtained.

Example 11:

In the broadband optical electromagnetic wave absorber based on refractory material in this embodiment, the gaps of the split nanorings are all 25 nanometers, and other parameters are the same as those in specific embodiment 1. The corresponding absorption spectrum as shown in Figure 6 can be obtained.

Example 12:

In the broadband optical electromagnetic wave absorber based on the refractory material in this embodiment, the gaps of the split nanorings are all 45 nanometers, and other parameters are the same as those of the specific embodiment 1. The corresponding absorption spectrum as shown in Figure 6 can be obtained. The absorption response of the absorber is best when the gap is 45 nm.

Example 13:

In the broadband optical electromagnetic wave absorber based on refractory material in this embodiment, the gaps of the split nanorings are all 65 nanometers, and other parameters are the same as those in specific embodiment 1. The corresponding absorption spectrum as shown in Figure 6 can be obtained.

Example 14:

In the broadband optical electromagnetic wave absorber based on refractory material in this embodiment, an anti-reflection silicon dioxide layer (the thickness can be 50 nm-300 nm) is added on top of the absorber in Embodiment 1, as shown in Figure 7 Refractory-based broadband optical electromagnetic wave absorber with four-layer structure shown.

Example 15:

In the broadband optical electromagnetic wave absorber based on refractory material in this embodiment, an anti-reflection silicon dioxide layer with a thickness of 130 nanometers is added on top of the absorber in embodiment 1. As shown in Figure 8, the silicon dioxide anti-reflection layer on the top layer with a thickness of 130 nm has the best absorption effect. The absorber achieves a broad band with absorptivity greater than 90% up to 3386 nm, from 685 nm to 4071 nm. The average absorptivity is as high as 94.35% in the spectral range from 600 nm to 4200 nm.

The above content is a further detailed description of the present invention in combination with specific preferred embodiments, and it cannot be considered that the specific implementation of the present invention is limited to these descriptions. For those of ordinary skill in the technical field of the present invention, without departing from the concept of the present invention, some simple deductions and substitutions can be made, which should be regarded as belonging to the protection scope of the present invention.

Claims (10)

1. a kind of broadband electromagnetic wave absorber based on refractory material, comprising:

Smooth metal film；

The dielectric nano-rings of the dielectric nano-rings of division of the array on the metal film, the division refer to that dielectric is received There are several gaps on meter Huan；

The metal nano ring of division in the dielectric nano-rings of the division is set, and the metal nano ring of the division refers to There are several gaps on metal nano ring.

2. the broadband electromagnetic wave absorber according to claim 1 based on refractory material, it is characterised in that: the division Dielectric nano-rings include four equally distributed gaps, the metal nano ring of the division includes four equally distributed Gap.

3. the broadband electromagnetic wave absorber according to claim 2 based on refractory material, it is characterised in that: described smooth The thickness of metal film be more than 150 nanometers, the material of the smooth metal film is titanium, nickel, chromium or tungsten.

4. the broadband electromagnetic wave absorber according to claim 2 based on refractory material, it is characterised in that: the division Dielectric nano-rings with a thickness of 1-300 nanometers, the material of the dielectric nano-rings of the division is silica, aluminium oxide Or magnesium fluoride.

5. the broadband electromagnetic wave absorber according to claim 2 based on refractory material, it is characterised in that: the division Metal nano ring thickness be 1-300 nanometer, the material of the metal nano ring of the division is titanium, nickel, chromium or tungsten.

6. the broadband electromagnetic wave absorber according to claim 2 based on refractory material, it is characterised in that: the division Dielectric nano-rings and the internal diameter and outer diameter of the metal nano ring of the division be consistent, internal diameter is 1-300 nanometers, outside Diameter is 300-800 nanometers.

7. the broadband electromagnetic wave absorber according to claim 1 based on refractory material, it is characterised in that: the array Period be greater than or equal to the division dielectric nano-rings outer diameter.

8. the preparation of the broadband electromagnetic wave absorber described in -7 any claims based on refractory material according to claim 1 Method, comprising the following steps:

(1) smooth substrate is provided；

(2) metallic diaphragm of specific thicknesses is deposited on substrate；

(3) dielectric membranous layer of specific thicknesses is deposited on step (2) metallic diaphragm obtained；

(4) metallic diaphragm of specific thicknesses is deposited on step (3) dielectric membranous layer obtained；

(5) it is performed etching using no mask electron beam lithography, focused-ion-beam lithography technology, obtains the metal nano ring of division The array structure of array structure and the dielectric nano-rings of division；

(6) it is cleaned using dehydrated alcohol, acetone, obtains the broadband electromagnetic wave absorber based on refractory material.

9. according to the method described in claim 8, it is characterized by: the substrate is quartz, glass, silicon wafer or organic film.

10. according to the method described in claim 8, it is characterized by: the deposition method includes magnetron sputtering method, vacuum coating One of method, metal fever evaporation coating method, pulse laser deposition, chemical plating method, atomic layer deposition method, electrochemical method Or several mixed method.