Multifunctional composite for photovoltaic fairings

Abstract

The present application relates to the field of photoelectric fairing material, and particularly relates to a multifunctional composite material for photoelectric fairing. The multifunctional composite material for photoelectric fairing comprises a substrate and a microwave shielding layer, an antireflection layer, an infrared low-emissivity layer and a high-temperature protection layer which are sequentially stacked on the substrate. The multifunctional composite material for photoelectric fairing is an advanced composite material with wide spectrum, high transmittance, low infrared emissivity and strong electromagnetic shielding performance, and can meet the requirements of photoelectric detection and electromagnetic protection of high-speed aircraft in extreme environments.

Description

Technical Field

[0001] This invention relates to the field of optoelectronic hood materials, and in particular to a multifunctional composite material for optoelectronic hoods. Background Technology

[0002] Modern high-speed aircraft optoelectronic detection systems face three major technical challenges: First, the thermal barrier problem, where high-speed flight causes fairing surface temperatures to exceed 300°C, drastically reducing the performance of traditional optical materials; second, infrared stealth, as the fairing's own infrared radiation is easily exposed to adversaries' infrared detection methods, and considering the temperature range, target infrared radiation is mainly concentrated in the 8-14μm band; and third, electromagnetic threats, where strong electromagnetic attacks can intrude into the aircraft's electronic systems through the optoelectronic window. To address these challenges, materials need to remain stable in high-temperature environments (≥300°C), while possessing high transmittance across a wide wavelength range (visible to infrared), low infrared emissivity (8-14μm band ε<0.20), and good microwave shielding performance (2-18GHz band shielding effectiveness ≥20dB).

[0003] Existing technologies typically employ multilayer composite structures, but these suffer from problems such as interlayer thermal stress mismatch and interface failure at high temperatures, and also present trade-offs between broadband anti-reflection and microwave shielding performance. Single-crystal materials such as sapphire and spinel are heat-resistant, but have high infrared emissivity (>0.8) and lack electromagnetic shielding capabilities; ITO transparent conductive films possess electromagnetic shielding properties, but their temperature resistance is insufficient (<200℃), and they affect optical transmittance; metal mesh structures degrade optical imaging quality and are difficult to meet broadband electromagnetic shielding requirements.

[0004] Therefore, there is an urgent need to develop a new type of multifunctional composite material that can simultaneously meet the above-mentioned multiple performance requirements and is suitable for the photoelectric windows of high-speed aircraft to cope with the extreme working environment they face. Summary of the Invention

[0005] Based on the above, the present invention provides a multifunctional composite material for an optoelectronic rectifier.

[0006] To achieve the above objectives, the present invention provides the following solution:

[0007] The present invention provides a multifunctional composite material for an optoelectronic rectifier, comprising a substrate and a microwave shielding layer, an anti-reflection layer, an infrared low-emission layer and a high-temperature protective layer sequentially stacked on the substrate.

[0008] In a preferred embodiment of the present invention, the substrate is yttrium aluminum garnet (Y3A). l5 O 12 The substrate is a YAG single crystal; the thickness of the substrate is 1.5-2 mm. In this invention, the substrate serves to provide mechanical support and high-temperature stability.

[0009] In the preferred embodiment of the present application, the microwave shielding layer adopts an embedded metal mesh-conductive oxide composite layer, wherein the metal mesh is a Cu mesh or an Ag mesh, and the conductive oxide is ITO or ZnO; the thickness of the conductive oxide is 10-18 μm, the line width of the metal mesh is 1.5-4 μm, and the period is 40-55 μm; and the thickness of the microwave shielding layer is 10-20 μm.

[0010] In the present application, the microwave shielding layer functions to achieve electromagnetic shielding at 2-18 GHz.

[0011] In the preferred embodiment of the present application, the anti-reflection layer adopts 3-6 layers of MgF2 / Al2O3 gradient films; the MgF2 / Al2O3 gradient films are a multilayer structure in which Al2O3 layers and MgF2 layers are alternately stacked, wherein the thickness of the Al2O3 layer is 110-140 nm, and the thickness of the MgF2 layer is 60-120 nm; and the Al2O3 layer of the bottom layer of the MgF2 / Al2O3 gradient films is directly attached to the surface of the microwave shielding layer.

[0012] In the preferred embodiment of the present application, the thickness of the anti-reflection layer is 150-250 nm. In the present application, the anti-reflection layer functions to improve the visible-infrared transmittance.

[0013] In the preferred embodiment of the present application, the infrared low-emission layer adopts an Ag / TiN or Au / TiO2 nano-composite coating; wherein the volume fraction of Ag in the Ag / TiN nano-composite coating is 15%-17%, and the volume fraction of Au in the Au / TiO2 nano-composite coating is 10%-13%; and the thickness of the infrared low-emission layer is 100-200 nm.

[0014] In the present application, the infrared low-emission layer functions to suppress infrared radiation at 8-14 μm.

[0015] In the preferred embodiment of the present application, the high-temperature protection layer adopts doped yttria-stabilized zirconia (Y2O3-ZrO2, YSZ) or AlON ceramic; and the thickness of the high-temperature protection layer is 50-100 μm.

[0016] In the present application, the high-temperature protection layer functions to achieve the effects of anti-erosion, anti-oxidation, and high-temperature resistance.

[0017] The present application realizes the synergistic effect of the functional layers through the following innovative design:

[0018] Thermal-optical-electrical coupling design: the material parameters of each layer are optimized as a whole to avoid mutual offset of functions;

[0019] Interlayer energy transfer control: the infrared suppression layer and the microwave shielding layer work in synergy to reduce heat accumulation;

[0020] Gradient interface engineering: solve the thermal stress mismatch problem of different CTE materials at high temperature;

[0021] Optical-electromagnetic collaborative design: metal mesh parameters and antireflection film system are jointly optimized, optical transmittance and electromagnetic shielding performance are considered.

[0022] The preparation method of the multifunctional composite material of the photoelectric fairing is not particularly limited in the present application, and the preparation method known to those skilled in the art is used, such as using nano-imprinting + electroplating to prepare a microwave shielding layer, using ion beam assisted deposition to prepare an antireflection layer, using magnetron sputtering to deposit an infrared low-emission layer, and using atmospheric plasma spraying to prepare a high-temperature protective layer.

[0023] The present application discloses the following technical effects:

[0024] The multifunctional composite material of the photoelectric fairing of the present application is an advanced composite material with wide spectrum, high transmittance, low infrared emissivity and strong electromagnetic shielding performance, which can meet the requirements of photoelectric detection and electromagnetic protection of high-speed aircraft in extreme environments. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort.

[0026] Figure 1 It is a structural schematic diagram of the multifunctional composite material of the photoelectric fairing of the present application.

[0027] Figure 2 It is a process flow schematic diagram for preparing the multifunctional composite material of the photoelectric fairing of the present application. DETAILED DESCRIPTION

[0028] The various exemplary embodiments of the present application will be described in detail below, which should not be considered as limiting the present application, but should be understood as a more detailed description of some aspects, characteristics and embodiments of the present application.

[0029] It should be understood that the terms described in the present application are only for describing the specific embodiments, and are not used to limit the present application. In addition, for the numerical range in the present application, it should be understood that each intermediate value between the upper limit and the lower limit of the range is also specifically disclosed. Each smaller range between any stated value or intermediate value in the stated range, and any other stated value or intermediate value in the stated range, is also included in the present application. The upper limit and the lower limit of these smaller ranges can be independently included or excluded from the range.

[0030] Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as those commonly understood by one of ordinary skill in the art to which this application pertains. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present application, the preferred methods and materials are described. All publications mentioned in this specification are herein incorporated by reference to disclose and describe the methods and / or materials in connection with which the publications are cited. The citation of any reference is not an admission that it is prior art with respect to the present application.

[0031] Many modifications and variations of this application can be made in the light of the above teachings without departing from the spirit and scope thereof. Other implementations of the application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. The specification and examples given are exemplary only.

[0032] As used herein, the terms "comprises", "comprising", "includes", "including", "has", "having", "contains", "containing", or variations thereof, are intended to be open-ended terms that mean including, but not limited to.

[0033] The technical solutions described in the present application are conventional solutions in the art unless otherwise specified, and the reagents or raw materials used are purchased from commercial channels or are publicly known unless otherwise specified.

[0034] The inorganic silicate resin used in the embodiments of the present application has a chemical formula of Na2O·51SiO2, wherein 51 represents the molar ratio of silicon dioxide to sodium oxide.

[0035] The thermal expansion coefficient CTE of the YAG single crystal used in the embodiments of the present application is 8.2×10 -6 / K<100>.

[0036] The test method involved in the present application is as follows:

[0037] The test of infrared emissivity refers to the Standard Test Method for Measuring Solar Absorptance Using Portable Emissometer of Near Room Temperature Materials Radiation, ASTM C1371-04, which is based on the reflection method (indirect method), uses a portable emissometer to measure the hemispherical-directional reflectance p(λ, θ) of the sample at a specific wavelength (usually 8-14 μm atmospheric window), and then calculates the normal emissivity according to the Kirchhoff's law and the law of conservation of energy (for opaque materials): ε(λ, θ) = 1 - p(λ, θ).

[0038] The test of visible transmittance refers to GB / T 2680 Architectural glazing. Determination of visible light transmission, solar direct transmission, and uses monochromator or grating spectrometer to measure the sample transmittance light intensity (I) and reference light intensity (I0) by wavelength, and transmittance T = I / I0. The test of infrared transmittance refers to GJB / J 3417 Military optical material. Measurement method of infrared transmittance, and Fourier transform infrared spectrometer is used to obtain the interference diagram of the infrared band, and the spectrum diagram is obtained by Fourier transform, and the transmittance is calculated.

[0039] The test of microwave shielding effectiveness refers to GB / T 12190 Measurement of shielding effectiveness of electromagnetic shielding chamber, and the antenna radiation method is used. The transmitting antenna and receiving antenna are placed in and outside the shielding chamber tool, respectively, the change of receiving power of the receiving antenna is tested under the condition that the tool window is shielded by the composite material, and the covered frequency band is 2-18GHz.

[0040] The technical solutions of the present application will be described in detail below in combination with the embodiments, but they should not be understood as limiting the scope of protection of the present application.

[0041] The structural schematic diagram of the multifunctional composite material of the photoelectric fairing is shown in Figure 1 .

[0042] The process flow diagram of the multifunctional composite material of the photoelectric fairing prepared in Example 1 is shown in Figure 2 .

[0043] Example 1

[0044] A multifunctional composite material of a photoelectric fairing is composed of a substrate, a microwave shielding layer, an anti-reflection layer, an infrared low-emission layer and a high-temperature protection layer which are sequentially stacked on the substrate. The high-temperature protection layer is made of doped yttria-stabilized zirconia (Y2O3-ZrO2, YSZ) with a thickness of 80 microns; the infrared low-emission layer is made of Ag / TiN (Ag volume fraction 15%) with a thickness of 150 nanometers; the anti-reflection layer is made of 5 layers of MgF2 / Al2O3 gradient film with a total thickness of 200 nanometers; the microwave shielding layer is made of ITO nanowire coating with a thickness of 15 microns, and the additional line width is 3 microns and the period is 50 microns Cu grid; and the substrate is YAG single crystal with a thickness of 1.8 mm.

[0045] The preparation method of the multifunctional composite material of the photoelectric fairing is as follows:

[0046] (1) Double-sided optical polishing of YAG single crystal substrate (Ra < 0.5 nm);

[0047] (2) Spin coating of ITO nanowire dispersion liquid (solid content 3%, solvent inorganic silicate resin) with a thickness of 15 microns and vacuum curing at 300 DEG C;

[0048] (3) PI surface micro-groove is made by nano-imprinting, and Cu is electroplated to form a grid with a line width of 3 μm and a period of 50 μm;

[0049] (4) Five layers of gradient MgF2 / Al2O3 antireflection films are deposited by ion beam assisted deposition;

[0050] (5) An Ag / TiN low-emission layer is deposited on the surface of the antireflection film by magnetron sputtering, wherein the volume fraction of Ag is 15%, and the Ag / TiN low-emission layer is annealed at 400°C for 1 hour under Ar gas protection;

[0051] (6) A YSZ protective layer is sprayed by atmospheric plasma (power 40 kW, powder feeding rate 30 g / min);

[0052] (7) The interface is strengthened by vacuum annealing (Ar gas protection, 600°C / 2h).

[0053] The preparation process can realize uniform preparation of large-area (≥Φ200 mm) materials, the thickness control precision of each layer is ±5%, and the interface bonding strength is ≥30 MPa.

[0054] The performance indicators of the photoelectric fairing multifunctional composite material prepared in Example 1 are shown in Table 1:

[0055] Table 1 Performance indicators of the material of Example 1

[0056] ,

[0057] The photoelectric fairing multifunctional composite material prepared in Example 1 is subjected to 100 hours of aging test at 350°C, and the changes in the related performance of the material are shown in Table 2:

[0058] Table 2 Aging test results of the material of Example 1

[0059] ,

[0060] As can be seen from Table 2, the performance attenuation of the photoelectric fairing multifunctional composite material prepared in Example 1 is small under high-temperature environment, which meets the long-term use requirement.

[0061] The gradient MgF2 / Al2O3 antireflection film in step (3) is a gradually changing refractive index design, which realizes smooth transition of the refractive index from the substrate side (n≈1.82) to the infrared low-emission layer by alternately stacking low-refractive-index MgF2 (n=1.38) and high-refractive-index Al2O3 (n=1.76), thereby reducing reflection loss in a wide spectral range. The specific structural parameters are shown in Table 3:

[0062] Table 3 Structure of MgF2 / Al2O3 multilayer film

[0063] .

[0064] Example 2

[0065] A multifunctional composite material for a photoelectric fairing, comprising a substrate and, sequentially stacked on the substrate, a microwave shielding layer, an antireflection layer, an infrared low-emission layer, and a high-temperature protection layer. The high-temperature protection layer is YSZ (Y2O3-ZrO2) with a thickness of 100 μm; the infrared low-emission layer is Ag / TiN (Ag volume fraction 17%) with a thickness of 200 nm; the antireflection layer is a 5-layer MgF2 / Al2O3 gradient film with a total thickness of 225.5 nm; the microwave shielding layer is a coating with ITO nanowires (solid content 3%, solvent inorganic silicate resin) with a thickness of 18 μm, and a Cu grid with a line width of 4 μm and a period of 55 μm; and the substrate is a YAG single crystal with a thickness of 2.0 mm.

[0066] The method for preparing the multifunctional composite material for a photoelectric fairing in this example is as described in Example 1.

[0067] The performance indicators of the multifunctional composite material for a photoelectric fairing prepared in this example are shown in Table 4:

[0068] Table 4 Performance indicators of the material in Example 2

[0069] ,

[0070] The multifunctional composite material for a photoelectric fairing prepared in Example 2 was subjected to 100 hours of aging test at 350°C, and the changes in the relevant performance of the material are shown in Table 5:

[0071] Table 5 Results of the aging test of the material in Example 2

[0072] ,

[0073] In this example, the specific structural parameters of the 5-layer MgF2 / Al2O3 gradient film are shown in Table 6:

[0074] Table 6 Structure of the MgF2 / Al2O3 multilayer film

[0075] .

[0076] Example 3

[0077] A multifunctional composite material for a photoelectric fairing, which differs from Example 1 only in that the high-temperature protection layer is 80 μm thick AlON ceramic.

[0078] The performance indicators of the multifunctional composite material for a photoelectric fairing prepared in this example are shown in Table 7:

[0079] Table 7 Performance indicators of the material in Example 3

[0080] ,

[0081] As can be seen from Table 7, AlON ceramics can achieve similar performance to YSZ protective layers, but at a lower cost, making them suitable for large-scale applications.

[0082] Example 4

[0083] A multifunctional composite material for an optoelectronic rectifier comprises a substrate and a microwave shielding layer, an antireflection layer, an infrared low-emission layer, and a high-temperature protection layer sequentially stacked on the substrate. The high-temperature protection layer is made of AlON ceramic with a thickness of 50 μm; the infrared low-emission layer is an Au / TiO2 (10% Au volume fraction) composite coating with a thickness of 100 nm; the antireflection layer is a three-layer MgF2 / Al2O3 gradient film with a total thickness of 177 nm; the microwave shielding layer is a 10 μm thick ZnO nanowire coating (5% solid content, inorganic silicate resin as solvent) with an additional Ag grid of 1.5 μm linewidth and 40 μm period; the substrate is a YAG single crystal with a thickness of 1.5 mm.

[0084] The preparation method of the multifunctional composite material for the optoelectronic rectifier in this embodiment is the same as that in Example 1.

[0085] The performance indicators of the multifunctional composite material for the optoelectronic rectifier prepared in this embodiment are shown in Table 8:

[0086] Table 8 Material performance indicators of Example 4

[0087] ,

[0088] The photoelectric rectifier multifunctional composite material prepared in Example 4 was subjected to a 100-hour aging test at 350℃. The changes in the relevant material properties are shown in Table 9.

[0089] Table 9. Material aging test results of Example 4

[0090] ,

[0091] In this embodiment, the specific structural parameters of the 3-layer MgF2 / Al2O3 gradient film are shown in Table 10:

[0092] Table 10 MgF2 / Al2O3 multilayer film structure

[0093] .

[0094] Example 5

[0095] A multifunctional composite material for an optoelectronic radome differs from Example 1 only in that the thickness of the infrared low-emission layer is 80 nm, while all other parameters are the same as in Example 1.

[0096] The performance indicators of the multifunctional composite material of the electro-optical radome prepared in this example are shown in Table 11:

[0097] Table 11 Performance indicators of materials in Example 5

[0098] ,

[0099] As can be seen from Table 11, the emissivity in the range of 8-14 μm increases due to the decrease in the thickness of the infrared low-emission layer, which does not meet the requirements.

[0100] Example 6

[0101] A multifunctional composite material of an electro-optical radome differs from Example 1 only in that the microwave shielding layer uses an ITO nanowire coating (solid content 3%, solvent inorganic silicate resin) with a thickness of 15 μm, and an additional Cu grid with a line width of 3 μm and a period of 80 μm; other parameters are the same as in Example 1.

[0102] The performance indicators of the multifunctional composite material of the electro-optical radome prepared in this example are shown in Table 12:

[0103] Table 12 Performance indicators of materials in Example 6

[0104] ,

[0105] As can be seen from Table 12, the microwave shielding efficiency decreases due to the increase in the period of the Cu grid to 80 μm.

[0106] Example 7

[0107] A multifunctional composite material of an electro-optical radome differs from Example 1 only in that the infrared low-emission layer uses an Au / TiO2 nanocomposite coating (Au particle size 30 nm, solid content 4%; TiO2 particle size 100 nm, solid content 5%; solvent inorganic silicate resin) with a thickness of 150 nm, and the infrared low-emission layer is prepared by brushing; other parameters are the same as in Example 1.

[0108] The performance indicators of the multifunctional composite material of the electro-optical radome prepared in this example are shown in Table 13:

[0109] Table 13 Performance indicators of materials in Example 7

[0110] ,

[0111] As can be seen from Table 13, the Au / TiO2 nanocomposite coating can achieve similar performance to the Ag / TiN nanocomposite film, and the preparation process is simpler, which is suitable for large-scale application.

[0112] Example 8

[0113] A multifunctional composite material for a photoelectric fairing, which differs from Example 1 only in that the antireflection layer is omitted, and other parameters are the same as in Example 1.

[0114] The performance indicators of the multifunctional composite material for a photoelectric fairing prepared in this example are shown in Table 14:

[0115] Table 14 Performance indicators of materials of Example 8

[0116] ,

[0117] As can be seen from Table 14, the absence of the antireflection layer leads to an increase in interface reflection loss (especially in the infrared waveband), directly weakening the light transmission, and the visible-infrared transmittance decreases from 78.2% to 65.4% (a decrease of 12.8%); through the 100h high-temperature aging test at 350°C, it is found that the visible-infrared transmittance after aging further decreases to 61.8%, which cannot meet the target of >75%. The stability of the infrared emissivity decreases, the initial emissivity increases to 0.19 (still meeting the standard), but after aging, it increases to 0.21 (exceeding the requirement of <0.20). The antireflection layer originally serves as a protective barrier for the infrared low-emission layer, and after removal, the Ag / TiN film is more prone to high-temperature oxidation, and the bonding strength decreases by 10.0% after aging (only decreases by 6.3% in Example 1), because the antireflection layer is missing to buffer the interface stress. The shielding effectiveness (22.5dB) and the temperature resistance (≥350°C) still meet the standards, because both of them depend on the metal mesh and the YSZ / YAG substrate.

[0118] Example 9

[0119] A multifunctional composite material for a photoelectric fairing, which differs from Example 1 only in that the high-temperature protective layer is a SiC ceramic layer (thermal expansion coefficient CTE=4.4×10 -6 / K) with a thickness of 80μm, which is prepared by plasma spraying; other parameters are the same as in Example 1.

[0120] The performance indicators of the multifunctional composite material for a photoelectric fairing prepared in this example are shown in Table 15:

[0121] Table 15 High-temperature test results of materials of Example 9

[0122] ,

[0123] As can be seen from Table 15, due to the large difference in the thermal expansion coefficients of the high-temperature protective layer and the substrate, the high-temperature resistance of the overall composite material is seriously deteriorated, and the far-infrared emissivity significantly increases after the high-temperature test.

[0124] Comparative Example 1

[0125] A multifunctional composite material for photoelectric rectenna was prepared, which was different from example 1 only in that the antireflection layer was a single layer of MgF2 with a thickness of 200 nm, and other parameters were the same as in example 1.

[0126] The performance indicators of the multifunctional composite material for photoelectric rectenna prepared in this comparative example are shown in Table 16:

[0127] Table 16 Performance indicators of the material of comparative example 1

[0128] .

[0129] Comparative example 2

[0130] The only difference between this example and example 1 is that the antireflection layer is changed to a double-layer structure: the first layer (close to the substrate): Al2O3, thickness 100 nm (n = 1.76); the second layer (outer layer): MgF2, thickness 100 nm (n = 1.38). The total thickness is 200 nm (the same as example 1), and the gradient refractive index design is cancelled. The performance comparison results are shown in Table 17.

[0131] Table 17 Performance indicators of the material of comparative example 2

[0132] ,

[0133] Example 1 uses the five-layer gradient film shown in Table 3 to achieve wide-spectrum antireflection (> 78%) through refractive index gradient (1.82→1.76→1.38), while the double-layer structure causes a nearly 10% reduction in transmittance due to the reflection of the abrupt interface, and the interface bonding strength significantly deteriorates at high temperatures.

[0134] Comparative example 3

[0135] The only difference between this example and example 1 is that the coating sequence is adjusted, and the adjusted coating sequence is: substrate→infrared low-emission layer (Ag / TiN)→microwave shielding layer (ITO+Cu grid)→antireflection layer→high-temperature protection layer. The parameters of each layer are the same as in example 1. The performance comparison results are shown in Table 18.

[0136] Table 18 Performance indicators of the material of comparative example 3

[0137] ,

[0138] Example 1 uses the sequence "substrate→microwave shielding layer→antireflection layer→infrared low-emission layer→high-temperature protection layer" to ensure that the Cu grid is exposed to the outermost layer (step 3) to achieve optimal shielding; Ag / TiN is placed above the antireflection layer to avoid optical loss; the YSZ protection layer isolates high-temperature oxidation. As can be seen from Table 18, the sequence adjustment causes the core function to fail.

[0139] Comparative example 4

[0140] The difference between Example 1 is only that the volume fraction of Ag in the infrared low-emission layer Ag / TiN is reduced to 8% (15% in Example 1). The performance comparison results are shown in Table 19.

[0141] Table 19 Performance indicators of the material of Comparative Example 4

[0142]

[0143] The volume fraction of Ag in Example 1 is 15%, which better guarantees the low emissivity (<0.20) at high temperature, and the performance significantly deteriorates after the parameter deviation.

[0144] Comparative Example 5

[0145] The difference between Example 1 is only that the microwave shielding layer only retains the ITO nanowire coating with a thickness of 15 μm, and the Cu grid structure is omitted. The performance comparison results are shown in Table 20.

[0146] Table 20 Performance indicators of the material of Comparative Example 5

[0147]

[0148] Example 1 adopts the composite structure of "15 μm ITO nanowire coating + Cu grid with a line width of 3 μm / period of 50 μm", and the shielding effectiveness is >22 dB in the full frequency band of 2-18 GHz. It can be seen from Table 20 that the high-frequency shielding performance of the single ITO layer is insufficient.

[0149] The above examples can show that the excellent performance of the multifunctional composite material of the photoelectric fairing is realized by the synergistic design of each functional layer:

[0150] The synergistic optical parameters of the infrared low-emission layer and the antireflection layer are the key to realize the far-infrared low-emissivity (ε <0.20) and the high transmittance of visible light-infrared light (>75%), and the presence of the antireflection layer is beneficial to the anti-aging performance of the whole material; the joint optimization of the geometric parameters (line width ≤5 μm, period ≤50 μm) of the metal grid and the antireflection film solves the inherent contradiction between the optical and electromagnetic performances; the difference of the thermal expansion coefficients of each layer of material needs to be controlled within ±1.5×10 -6 / K, and the thermal matching is realized through the gradient interface design; the composite structure of the metal grid and the transparent conductive oxide (ITO / ZnO) in the microwave shielding layer simultaneously meets the requirements of high-temperature stability and shielding effectiveness. In the present application, the isolated optimization of each parameter cannot realize the overall performance standard, and the multi-physical field synergistic design method of the present application must be used.

[0151] ​​The above described embodiments are only to illustrate the preferred modes of the present application, and are not intended to limit the scope of the present application. Any modification and improvement made by those skilled in the art to the technical solutions of the present application without departing from the design spirit of the present application shall fall within the protection scope of the present application as defined by the claims.

Claims

1. A multifunctional composite for photovoltaic rudder, characterized in that, The substrate and a microwave shielding layer, an anti-reflection layer, an infrared low-emission layer and a high-temperature protection layer which are sequentially stacked on the substrate; The microwave shielding layer is a composite layer of embedded metal mesh and conductive oxide, wherein the metal mesh is Cu mesh or Ag mesh, and the conductive oxide is ITO or ZnO; The anti-reflection layer is a 3-5 layer MgF2 / Al2O3 gradient film; The infrared low-emission layer is an Ag / TiN or Au / TiO2 nano-composite coating.

2. The opto-electrical fairing multifunctional composite material according to claim 1, characterized in that, The substrate is yttrium aluminum garnet single crystal, and the thickness of the substrate is 1.5-2 mm.

3. The opto-electrical fairing multifunctional composite material according to claim 1, characterized in that, The thickness of the conductive oxide is 10-18 μm, the line width of the metal mesh is 1.5-4 μm, and the period is 40-55 μm; the thickness of the microwave shielding layer is 10-20 μm.

4. The opto-electrical fairing multifunctional composite material according to claim 1, characterized in that, The MgF2 / Al2O3 gradient film is a multilayer structure in which Al2O3 layers and MgF2 layers are alternately stacked, wherein the thickness of the Al2O3 layer is 110-140 nm, and the thickness of the MgF2 layer is 60-120 nm; the Al2O3 layer of the bottom layer of the MgF2 / Al2O3 gradient film directly adheres to the surface of the microwave shielding layer.

5. The opto-electrical spinner multi-functional composite material according to claim 1 or 4, characterized in that, The thickness of the anti-reflection layer is 150-250 nm.

6. The opto-electrical spinner multi-functional composite material of claim 1, wherein, The volume fraction of Ag in the Ag / TiN nano-composite coating is 15%-17%, and the volume fraction of Au in the Au / TiO2 nano-composite coating is 10%-13%; the thickness of the infrared low-emission layer is 100-200 nm.

7. The opto-electrical spinner multi-functional composite material of claim 1, wherein, The high-temperature protection layer is doped yttria-stabilized zirconia or AlON ceramic; and the thickness of the high-temperature protection layer is 50-100 μm.

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