Visible infrared dual-band stealth material and preparation method thereof

Abstract

The invention discloses a visible infrared dual-band stealth material and a preparation method thereof. The material structurally comprises a metal Mo layer, a Ge dielectric layer and an Al2O3 dielectric layer, and the metal Mo layer, the Ge dielectric layer and the Al2O3 dielectric layer are sequentially laid from bottom to top. According to the method, the absorptivity, the refractive index and the transmittance of the thin film structure in visible light and infrared bands are calculated through combination of a transmission matrix and simulation software, and simulated absorption spectrums of the thin film structure in the visible light and infrared bands under the normal incidence condition are obtained; by changing the thickness of each layer of material in the thin film structure, different thickness absorption spectrums of the thin film structure in visible light and infrared bands are obtained through calculation; comparing the different thickness absorption spectrums with the simulated absorption spectrums to obtain an optimal thin film structure and the thickness of each layer of material; and according to the thickness of each layer of material of the optimal thin film structure, a target thin film structure is prepared by setting a preparation mode. The structure is simple, the manufacturing process is simplified, and preparation and large-scale integration are easy.

Description

Technical Field

[0001] The present invention relates to the technical field of infrared stealth material preparation, and particularly relates to a visible and infrared dual-band stealth material and a preparation method thereof. Background Art

[0002] With the continuous development of science and technology, the accuracy of infrared detection systems has been continuously improved. Moreover, multi-spectral detection technologies combining multiple advanced detection systems have been applied to our daily lives and are becoming increasingly mature. Traditional single-band stealth technologies can no longer meet people's usage requirements, which poses a huge challenge to the concealment of stealth targets. Therefore, in order to cope with the combination of advanced detectors in different bands and improve the stealth ability of targets, achieving compatible stealth between different bands has become an urgent need. However, due to the different stealth principles in different bands, achieving a multi-band stealth function covering a wide spectral range has also become a difficult task. Specifically, to achieve the stealth of a target in the visible light band, we mainly achieve it by using a camouflage coating to make the optical characteristics of the target consistent with the background environment or by reducing the surface reflectivity of the target; while for achieving the stealth function of a target in the infrared band, the key lies in changing the infrared radiation characteristics of the target so that the infrared radiation of the target is similar to the background environment within the detection accuracy range of the infrared detection system. Generally speaking, the infrared radiation of an object is higher than that of the background environment. According to the Stefan-Boltzmann law, we know that the infrared radiation of an object is proportional to the emissivity of its surface and the fourth power of the target surface temperature. Therefore, we can suppress the infrared radiation of the target by reducing the temperature and emissivity of the target. Usually, when the target is in a thermally stable state, its temperature is difficult to change. Therefore, reducing the emissivity of the target by certain means is the main method to achieve infrared stealth; as for the stealth against active detection systems in other bands including microwave and lidar, we need to reduce the radar cross section (RCS) and laser reflection signal in the microwave radar band (2-18 GHz) and laser wavelengths (1.06 μm, 1.55 μm, and 10.6 μm) by increasing the high absorptivity of the target. Therefore, in view of the above different band stealth principles, how to adopt appropriate methods to achieve the multi-band compatible stealth function of the target has become a hot issue in current research.

[0003] In recent years, the rise of metamaterials has opened up a way to solve this problem. Electromagnetic metamaterials (referred to as metamaterials for short) are artificial micro-nano structured materials that have artificially designed structures at the sub-wavelength scale and exhibit extraordinary physical properties not found in natural materials. By adjusting the size and geometric shape of the metamaterial structure, the desired dielectric constant or magnetic permeability can be obtained, thereby controlling the position of the structural resonance absorption peak in bands such as visible light, infrared, and microwave, and ultimately achieving wavelength-selective absorption. In recent years, some scientists have achieved compatible stealth in bands such as visible light, infrared, and microwave to a certain extent through the structural design of metamaterials. Although these works can achieve compatible stealth of the target in some bands, many problems still remain. Moreover, most of the structures designed in these works are relatively complex, bringing great trouble to the preparation of samples, resulting in high processing costs and large processing difficulties, making it impossible to carry out large-scale integration and application, and the practicability cannot be guaranteed.

[0004] Therefore, how to invent a visible-infrared dual-band stealth material with a multi-layer film structure and its preparation method, simplify the manufacturing process, and be easy to prepare and large-scale integrate has become an urgent problem to be solved. Summary of the Invention

[0005] For this reason, the present invention provides a visible-infrared dual-band stealth material and its preparation method. By using the method of multi-layer film stacking and utilizing the structural design at the micro-nano scale to achieve the spectral selective absorption of the target, the structure can achieve high-absorption stealth in the visible light band and infrared stealth and radiation heat dissipation matching the infrared band and the atmospheric window, and the designed structure is relatively simple, the manufacturing process is simplified, and it is easy to prepare and large-scale integrate.

[0006] To achieve the above object, the present invention provides the following technical solution: A visible-infrared dual-band stealth material includes a metal Mo layer, a Ge dielectric layer, and an Al 2 O 3 dielectric layer; the metal Mo layer, the Ge dielectric layer, and the Al 2 O 3 dielectric layer are laid flat in sequence from bottom to top.

[0007] As a preferred scheme of a visible-infrared dual-band stealth material, the thickness of the metal Mo layer is greater than the skin depth of the incident light.

[0008] As a preferred scheme of a visible-infrared dual-band stealth material, the thickness of the Ge dielectric layer is adjusted according to the resonance requirements of the thin film structure; the Ge dielectric layer is used to adjust the resonance absorption characteristics of the thin film structure in the visible light and infrared bands.

[0009] As a preferred scheme of a visible-infrared dual-band stealth material, the Al 2 O3 The thickness of the dielectric layer is adjusted according to the resonance requirements of the thin film structure; the Al 2 O 3 The dielectric layer is used to adjust the resonance absorption characteristics of the thin film structure in the visible light band.

[0010] The present invention also provides a method for preparing a visible-infrared dual-band stealth material, including:

[0011] Calculating the absorption rate, refractive index, and transmittance of the thin film structure in the visible and infrared bands through the transfer matrix combined with simulation software to obtain the simulation absorption spectrum of the thin film structure in the visible and infrared bands under normal incidence;

[0012] By changing the thickness of each layer of material in the thin film structure, different thickness absorption spectra of the thin film structure in the visible and infrared bands are calculated; comparing the different thickness absorption spectra with the simulation absorption spectrum to obtain the optimal thin film structure and the thickness of each layer of material;

[0013] According to the thickness of each layer of material in the optimal thin film structure, a target thin film structure is prepared by setting the preparation method.

[0014] As a preferred scheme of the method for preparing a visible-infrared dual-band stealth material, during the process of calculating the simulation absorption spectrum through the transfer matrix combined with simulation software, the sensitivity of the absorption characteristics of the thin film structure is analyzed according to the incident angle and polarization state of the incident light to obtain sensitivity data; the thin film structure is optimized according to the sensitivity data.

[0015] As a preferred scheme of the method for preparing a visible-infrared dual-band stealth material, the calculation formula for the absorption rate is:

[0016] A = 1 - T - R

[0017] In the formula, A is the absorption rate of the thin film structure; R is the reflectance of the thin film structure; T is the transmittance of the thin film structure.

[0018] As a preferred scheme of the method for preparing a visible-infrared dual-band stealth material, during the process of preparing the target thin film structure by setting the preparation method, the set preparation method includes: magnetron sputtering method and atomic layer deposition (ALD) method.

[0019] As a preferred scheme of the method for preparing a visible-infrared dual-band stealth material, the absorption spectrum of the thin film structure in the visible light band is tested by a micro-area transmission-reflection test system, and the absorption spectrum of the thin film structure in the infrared band is tested by a Fourier transform infrared spectrometer.

[0020] As a preferred solution for the preparation method of a visible and infrared dual-band stealth material, during the process of preparing the target thin film structure, the metal Mo layer and the Ge dielectric layer are prepared by the magnetron sputtering method; the Al 2 O 3 dielectric layer is prepared by atomic layer deposition (ALD).

[0021] The present invention has the following advantages: The present invention includes a metal Mo layer, a Ge dielectric layer, and Al 2 O 3 dielectric layer; the metal Mo layer, the Ge dielectric layer, and the Al 2 O 3 dielectric layer are tiled in sequence from bottom to top. The present invention calculates the absorption rate, refractive index, and transmittance of the thin film structure in the visible and infrared bands through the transfer matrix combined with simulation software, and obtains the simulation absorption spectrum of the thin film structure in the visible and infrared bands under normal incidence; by changing the thickness of each layer material in the thin film structure, the absorption spectra of different thicknesses of the thin film structure in the visible and infrared bands are calculated; the absorption spectra of different thicknesses are compared with the simulation absorption spectrum to obtain the optimal thin film structure and the thickness of each layer material; according to the thickness of each layer material of the optimal thin film structure, by setting the preparation method, the target thin film structure is prepared. The present invention uses a multi-layer film stacking method to achieve target spectral selective absorption through micro-nano scale structural design, so that the structure can achieve high absorption stealth in the visible light band and infrared stealth and radiation heat dissipation matching the infrared band and the atmospheric window. This structure consists of three thin films. First, the absorption spectrum of the thin film structure in the visible and infrared bands is theoretically calculated through the transfer matrix, and the absorption spectrum under normal incidence is obtained. From the calculation results, the absorption rate of this structure in the visible light band is relatively high, and it can achieve the low reflectivity visible light stealth function. At the same time, in the infrared band, it can match well with the atmospheric infrared window, and has a low absorption rate in the atmospheric window band with a high infrared transmittance, so it can achieve infrared stealth function, while the absorption rate in the non-atmospheric window band is relatively high, and it can achieve both visible light and infrared dual-band stealth while taking into account good radiation heat dissipation ability. And the thin film structure proposed by the present invention is simple and easy to prepare. Through methods such as magnetron sputtering, the optimized structure is prepared, and the absorption spectrum of the obtained sample in the visible and infrared bands is measured. From the measurement results, it is basically consistent with the results obtained by theoretical calculation, which proves the feasibility of the present invention in practical use. The present invention has very important significance for the research and application of multi-spectral stealth technology. Description of the Drawings

[0022] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only exemplary. For those of ordinary skill in the art, without creative efforts, other implementation drawings can be obtained based on the provided drawings.

[0023] The structures, proportions, sizes, etc. shown in this specification are only used to cooperate with the content disclosed in the specification for those familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention. Therefore, they do not have a substantial technical meaning. Any modification of the structure, change in the proportional relationship, or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope covered by the technical content disclosed in the present invention.

[0024] Figure 1 It is a schematic structural diagram of a visible-infrared dual-band stealth material provided in Embodiment 1 of the present invention;

[0025] Figure 2 It is a schematic flow diagram of a preparation method of a visible-infrared dual-band stealth material provided in Embodiment 2 of the present invention;

[0026] Figure 3 It is a schematic diagram of the relationship between the absorption rate and wavelength of the present invention in the visible and infrared bands in the preparation method of a visible-infrared dual-band stealth material provided in Embodiment 2 of the present invention;

[0027] Figure 4 It is a schematic diagram of the field distribution at the resonance absorption peaks of the present invention in the visible and infrared bands in the preparation method of a visible-infrared dual-band stealth material provided in Embodiment 2 of the present invention;

[0028] Figure 5 It is a schematic diagram of the sample diagram of the thin film structure and the cross-sectional photo under a scanning electron microscope (SEM) in the preparation method of a visible-infrared dual-band stealth material provided in Embodiment 2 of the present invention; among them, (a) is the sample diagram of the thin film structure; (b) is the cross-sectional photo under a scanning electron microscope (SEM);

[0029] Figure 6 It is a schematic diagram of the absorption spectrum measured by the present invention of the thin film structure under a micro-area transmission and reflection test system and a Fourier transform infrared spectrometer in the preparation method of a visible-infrared dual-band stealth material provided in Embodiment 2 of the present invention. Specific Embodiments

[0030] The following specific embodiments illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0031] Embodiment 1

[0032] Referring to Figure 1 , Embodiment 1 of the present invention provides a visible and infrared dual-band stealth material, including a metal Mo layer, a Ge dielectric layer, and an Al 2 O 3 dielectric layer; the metal Mo layer, the Ge dielectric layer, and the Al 2 O 3 dielectric layer are tiled in sequence from bottom to top.

[0033] Specifically, the thin film structure is composed of multiple layers of films, and the structure extends infinitely in the x and y directions. The bottom layer is the metal Mo layer, the middle layer is the Ge dielectric layer, and the top layer is the Al 2 O 3 dielectric layer.

[0034] In this embodiment, the thickness of the metal Mo layer is greater than the skin depth of the incident light.

[0035] Specifically, the thickness of the metal Mo layer is greater than the skin depth of the incident light, so as to ensure that the transmittance of the thin film structure to the incident light is almost zero.

[0036] In this embodiment, the thickness of the Ge dielectric layer is adjusted according to the resonance requirements of the thin film structure; the Ge dielectric layer is used to adjust the resonance absorption characteristics of the thin film structure in the visible and infrared bands.

[0037] In this embodiment, the thickness of the Al 2 O 3 dielectric layer is adjusted according to the resonance requirements of the thin film structure; the Al 2 O 3 dielectric layer is used to adjust the resonance absorption characteristics of the thin film structure in the visible band.

[0038] In summary, the present invention includes a metal Mo layer, a Ge dielectric layer, and an Al 2 O 3 dielectric layer; the metal Mo layer, the Ge dielectric layer, and the Al 2 O 3 dielectric layer are tiled in sequence from bottom to top. The thickness of the metal Mo layer is greater than the skin depth of the incident light. The Ge dielectric layer and the Al 2O 3 The thickness of the dielectric layer can be adjusted according to the resonance requirements of the thin film structure; the Ge dielectric layer and the Al 2 O 3 dielectric layers are both used to adjust the resonance absorption characteristics of the thin film structure in the visible and infrared bands. In the present invention, the thickness of each layer of the thin film structure can be adjusted according to the resonance requirements of the structure. The structure of the present invention is relatively simple, the manufacturing process is simplified, and it is easy to prepare and integrate on a large scale.

[0039] Example 2

[0040] See Figure 2 , Example 2 of the present invention also provides a method for preparing a visible-infrared dual-band stealth material, including:

[0041] S1. Calculate the absorption rate, refractive index and transmittance of the thin film structure in the visible and infrared bands through the transfer matrix combined with simulation software, and obtain the simulation absorption spectrum of the thin film structure in the visible and infrared bands under normal incidence;

[0042] S2. By changing the thickness of each layer of material in the thin film structure, calculate and obtain the absorption spectra of different thicknesses of the thin film structure in the visible and infrared bands; compare the absorption spectra of different thicknesses with the simulation absorption spectrum to obtain the optimal thin film structure and the thickness of each layer of material;

[0043] S3. According to the thickness of each layer of material in the optimal thin film structure, set the preparation method to prepare the target thin film structure.

[0044] In this embodiment, in step S1, calculate the absorption rate, refractive index and transmittance of the thin film structure in the visible and infrared bands through the transfer matrix combined with simulation software, and obtain the simulation absorption spectrum of the thin film structure in the visible and infrared bands under normal incidence;

[0045] Specifically, theoretically calculate the absorption rate, refractive index and transmittance of the thin film structure in the visible and infrared bands through the transfer matrix combined with simulation software, and obtain the simulation absorption spectra of the thin film structure in the two bands under normal incidence;

[0046] Among them, the calculation formula for the absorption rate is:

[0047] A = 1 - T - R

[0048] In the formula, A is the absorption rate of the thin film structure; R is the reflectivity of the thin film structure; T is the transmittance of the thin film structure.

[0049] Since the thickness of the substrate is sufficient, the transmittance T can be regarded as almost 0. Therefore, by selecting an appropriate thickness of the dielectric layer, the impedance of the structure can be matched with that of air, so that the reflectivity of the structure is 0, thereby achieving nearly 100% perfect absorption. Since the structure has a high degree of symmetry, it is polarization-independent. For incident light with different polarization states under normal incidence, the absorption of the structure is the same. As Figure 3 shown, it is a graph of the relationship between the absorption rate of the thin film structure and the incident light wavelength in the visible and infrared bands under normal incidence. From Figure 3 it can be seen that the present invention can well realize the dual-band stealth function in the visible and infrared bands. In the visible band, the absorption rate of the structure is relatively high, and low-reflectivity visible light stealth can be achieved; at the same time, in the infrared band, it can be matched with the atmospheric absorption spectrum line. The absorption rate in the atmospheric window is relatively low, and infrared stealth function can be achieved. And it has a relatively high absorption rate and a relatively wide absorption bandwidth in the non-atmospheric window, and can better realize the radiation heat dissipation in the non-atmospheric window.

[0050] In this embodiment, in order to better understand the absorption of each layer of the thin film structure for incident light, the field distribution diagrams at the resonance absorption peaks in the visible and infrared bands are analyzed. As Figure 4 shown, it can be clearly seen that in the visible band, the electric field of the incident electromagnetic wave is mainly distributed in the top Al 2 O 3 dielectric layer, while in the lower Ge and Mo layers, it significantly attenuates to nearly zero. As for the infrared band, the electric field of the incident electromagnetic wave is also mainly distributed in the top Al 2 O 3 dielectric layer, rapidly attenuates in the middle Ge dielectric layer, and approaches zero in the bottom Mo layer.

[0051] In this embodiment, in step S2, by changing the thickness of each layer material in the thin film structure, the absorption spectra of the thin film structure with different thicknesses in the visible and infrared bands are calculated; the absorption spectra with different thicknesses are compared with the simulation absorption spectra to obtain the optimal thin film structure and the thickness of each layer material;

[0052] Specifically, according to the material characteristics, previous experience and theoretical models, the change range of the thickness of each layer is initially set. For example, for the metal Mo layer, considering its key influence on light absorption and shielding, the thickness change range can be set to 50 - 200 nm, with a step size of 10 nm; the Ge dielectric layer is mainly used to adjust resonance, and the thickness change range is set to 100 - 1000 nm, with a step size of 10 nm; Al 2 O 3The dielectric layer plays an important role in the surface characteristics. The thickness range is set to 10-80nm with a step length of 1nm. As the research progresses, the range and step length will be fine-tuned based on the preliminary calculation results, focusing on areas with better effects to improve calculation efficiency and optimization accuracy. The absorption spectra of different thicknesses of the thin film structure in the visible light and infrared bands are obtained by calculation. The absorption spectra of different thicknesses are compared with the simulated absorption spectra to select the most ideal thin film structure and the thickness of each layer of material.

[0053] In this embodiment, in step S3, a target thin film structure is prepared by setting a preparation method according to the thickness of each layer of material of the optimal thin film structure.

[0054] Specifically, the target thin film structure is prepared by a vacuum magnetron sputtering coating machine according to the thickness of each layer of the optimal thin film structure.

[0055] In this embodiment, a metal Mo layer, a Ge dielectric layer and an Al layer are sequentially formed on the silicon wafer. 2 O 3 Deposition of dielectric layer. The sputtering power of the metal Mo layer is 100W, the working pressure is 0.5Pa, and the deposition rate is about 10nm / min; the sputtering power of the dielectric Ge layer is 150W, the working pressure is 0.5Pa, and the deposition rate is about 20.5nm / min. Al is deposited by atomic layer deposition (ALD). 2 O 3 The dielectric layer grows at a rate of 0.11 nm per cycle.

[0056] At the same time, the generated optical images of the thin film structure samples, such as Figure 5 As shown in part (a) of the figure, a cross-sectional view of a thin film structure sample obtained by scanning electron microscopy (SEM) is shown in Figure 5 As shown in part (b) of Figure 5 As can be seen in part (a), due to the high absorption of the thin film structure in the visible light band, the sample as a whole appears dark in color, which is consistent with the results obtained from theoretical calculations.

[0057] In this embodiment, the absorption spectrum of the prepared thin film structure sample in the visible light and infrared bands is measured by a micro-area transflection test system and a Fourier transform infrared spectrometer and compared with the absorption spectrum obtained by simulation calculation, such as Figure 6As shown. It can be found from the absorption spectrum that the difference between the absorption spectrum of the thin film structure sample and the theoretical absorption spectrum obtained in the calculation is small, and there is only a slight shift between the resonance absorption peaks. Analyzing the reasons, it may be due to certain problems in the coating process and the measurement of the sample thickness. For example, there are certain deviations in the measured material sputtering rate in the early stage, and the accuracy of the equipment for measuring the thickness is relatively low. As a result, there is a certain deviation between the thickness of the corresponding layer of the actually prepared sample and the thickness applied in the simulation, so there is a certain difference between the calculated and theoretical absorption spectra. Subsequently, the coating process can be further optimized to make the experiment more accurate, thereby further reducing the difference between the experimental results and the simulation.

[0058] In summary, the present invention calculates the absorption rate, refractive index and transmittance of the thin film structure in the visible and infrared bands through the transfer matrix combined with simulation software, and obtains the simulated absorption spectrum of the thin film structure in the visible and infrared bands under normal incidence; by changing the thickness of each layer of material in the thin film structure, the absorption spectra of different thicknesses of the thin film structure in the visible and infrared bands are calculated; the absorption spectra of different thicknesses are compared with the simulated absorption spectrum to obtain the optimal thin film structure and the thickness of each layer of material; according to the thickness of each layer of material of the optimal thin film structure, by setting the preparation method, the target thin film structure is prepared. The present invention uses the method of stacking multiple layers of films and realizes the target spectral selective absorption through the structural design at the micro-nano scale, so that the structure can achieve high-absorption stealth in the visible light band and infrared stealth and radiation heat dissipation matching the infrared band and the atmospheric window. The structure is composed of three thin films. First, the transfer matrix is used to theoretically calculate the absorption of the thin film structure in the visible and infrared bands, and the absorption spectrum under normal incidence is obtained. From the calculation results, the absorption rate of the structure in the visible light band is relatively high, and the low-reflectivity visible light stealth function can be realized. At the same time, it can be well matched with the atmospheric infrared window in the infrared band. It has a low absorption rate in the atmospheric window band with a high infrared transmittance, so the infrared stealth function can be realized, while the absorption rate in the non-atmospheric window band is relatively high, and it can take into account good radiation heat dissipation ability while realizing visible and infrared dual-band stealth. And the thin film structure proposed by the present invention is simple and easy to prepare. Through magnetron sputtering and other methods, the optimized structure is prepared, and the absorption spectrum of the obtained sample in the visible and infrared bands is measured. From the measurement results, it is basically consistent with the results obtained by theoretical calculation, which proves the feasibility of the present invention in practical use. The present invention has very important significance for the research and application of multi-spectral stealth technology.

[0059] In the foregoing, the present invention has been described in relatively specific and detailed manner through general descriptions and specific embodiments. It should be understood that based on the technical concept of the present invention, several conventional adjustments or further innovations can also be made to these specific embodiments; however, as long as they do not depart from the technical concept of the present invention, the technical solutions obtained by these conventional adjustments or further innovations also fall within the protection scope of the claims of the present invention.

Claims

1. A visible infrared dual-band stealth material, characterized in that: It comprises a metal Mo layer, a Ge dielectric layer and an Al2O3 dielectric layer; the metal Mo layer, the Ge dielectric layer and the Al2O3 dielectric layer are laid in sequence from bottom to top.

2. The visible infrared dual-band stealth material according to claim 1, characterized in that: The thickness of the metal Mo layer is greater than the skin depth of the incident light.

3. The visible infrared dual-band stealth material according to claim 2, characterized in that: The thickness of the Ge dielectric layer is adjusted according to the resonance requirements of the thin film structure; the Ge dielectric layer is used to adjust the resonance absorption characteristics of the thin film structure in the visible light and infrared bands.

4. The visible infrared dual-band stealth material according to claim 3, characterized in that: The thickness of the Al2O3 dielectric layer is adjusted according to the resonance requirements of the thin film structure; the Al2O3 dielectric layer is used to adjust the resonance absorption characteristics of the thin film structure in the visible light band.

5. A method for preparing a visible infrared dual-band stealth material, characterized in that: include: The absorptivity, refractive index and transmittance of the thin film structure in the visible light and infrared bands are calculated by combining the transmission matrix with simulation software, and the simulated absorption spectrum of the thin film structure in the visible light and infrared bands under normal incidence is obtained; By changing the thickness of each layer of material in the thin film structure, different thickness absorption spectra of the thin film structure in the visible light and infrared bands are calculated; the different thickness absorption spectra are compared with the simulated absorption spectra to obtain the optimal thin film structure and the thickness of each layer of material; According to the thickness of each layer of material of the optimal thin film structure, the target thin film structure is prepared by setting the preparation method.

6. The method for preparing a visible infrared dual-band stealth material according to claim 5, characterized in that: In the process of calculating the simulated absorption spectrum by combining the transmission matrix with the simulation software, the sensitivity of the absorption characteristics of the thin film structure is analyzed according to the incident angle and polarization state of the incident light to obtain sensitivity data; The film structure is optimized based on the sensitivity data.

7. The method for preparing a visible infrared dual-band stealth material according to claim 6, characterized in that: The calculation formula of the absorption rate is: A=1-TR Wherein, A is the absorptivity of the thin film structure; R is the reflectivity of the thin film structure; and T is the transmittance of the thin film structure.

8. The method for preparing a visible infrared dual-band stealth material according to claim 7, characterized in that: In the process of preparing the target thin film structure by using the set preparation method, the set preparation method includes: a magnetron sputtering method and an atomic layer deposition ALD method.

9. The method for preparing a visible infrared dual-band stealth material according to claim 8, characterized in that: The absorption spectrum of the thin film structure in the visible light band is tested by a micro-area transflection test system, and the absorption spectrum of the thin film structure in the infrared band is tested by a Fourier transform infrared spectrometer.

10. The method for preparing a visible infrared dual-band stealth material according to claim 9, characterized in that: In the process of preparing the target thin film structure, the metal Mo layer and the Ge dielectric layer are prepared by the magnetron sputtering method; and the Al2O3 dielectric layer is prepared by the atomic layer deposition method.

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