Low layer number one-dimensional infrared low emissivity film system structure insensitive to polarization and incident angle

Abstract

The application relates to a low-layer one-dimensional infrared low-emissivity film structure which is insensitive to polarization and incident angle. The technical scheme is as follows: the low-layer one-dimensional infrared low-emissivity film structure is composed of a one-dimensional lambda / 4 periodic photonic crystal structure and a quasi-periodic photonic crystal structure, the last layer of the one-dimensional lambda / 4 periodic photonic crystal structure is connected with the top layer of the quasi-periodic photonic crystal structure. The low-layer one-dimensional infrared low-emissivity film structure is expressed by the following formula: (AB) 2 (CD) 5 ; wherein: (AB) 2 represents the one-dimensional lambda / 4 periodic photonic crystal structure, (AB) represents a sub-periodic photonic crystal structure in which Ge and ZnO are arranged in sequence; (CD) 5 represents the quasi-periodic photonic crystal structure, and (CD) represents a sub-quasi-periodic photonic crystal structure in which Ge and ZnO are arranged in sequence. The application has the characteristics of few layers, short production cycle, high reliability, realization of double-band low emission and insensitivity to polarization and incident angle.

Description

Technical Field

[0001] This invention belongs to the technical field of low-layer-count one-dimensional infrared low-emissivity film structures. Specifically, it relates to a low-layer-count one-dimensional infrared low-emissivity film structure that is insensitive to polarization and incident angle. Background Technology

[0002] Infrared light is an electromagnetic wave invisible to the human eye, but infrared detectors can detect and track targets by detecting the infrared radiation emitted by them. Currently, military equipment with infrared detection capabilities is used on various land, sea, and air combat platforms, playing a crucial role in rapidly assessing the battlefield situation. Therefore, infrared detection technology is indispensable in modern warfare. With the widespread use of infrared detection technology, low-emissivity infrared materials have also attracted the attention of engineers.

[0003] For example, Liu Y, Li H, Tong H, et al. Rational design and construction of [Si / SiO2] N One-dimensional photonic crystal for low infrared emissivity and visible light camouflage[J]. Optics and Lasers in Engineering, 2023, 168: 107673.) Theoretical and experimental studies were conducted on Si / SiO2 one-dimensional photonic crystals, and the prepared [Si / SiO2] crystals were obtained. N Photonic crystals can achieve an average reflectivity of 95.23% in the 3–5 μm band. However, they have not achieved the high reflectivity of photonic crystal structures in the 8–14 μm band, and their operating band is limited.

[0004] For example, the patented technology of "one-dimensional metal-reinforced film structure with low layer count and high far-infrared reflectivity" (CN108873111A) uses a one-dimensional metal-reinforced film structure with a total of 23 layers, which can simultaneously achieve high reflectivity in the 3-5μm and 8-14μm infrared bands. Although it is possible to achieve high infrared reflectivity in both the 3-5μm and 8-14μm bands simultaneously through the superposition of photonic crystals, this generally requires the design of a film structure with more than 20 layers, resulting in long production cycles and reduced reliability.

[0005] For example, Jiang et al. (Jiang X, Yuan H, He X, et al. Implementing of infrared camouflage with thermal management based on inverse design and hierarchical metamaterial[J]. Nanophotonics, 2023, 5(10): 1891-1902.) proposed a multilayer film structure composed of five materials: SiO2, Ge, ZnS, Pt, and Au. At a TM polarization angle of 60°, the multilayer film structure composed of SiO2, Ge, ZnS, Pt, and Au exhibits a reflectivity of approximately 40% at 12.5 μm, failing to achieve good polarization insensitivity.

[0006] In summary, the existing technology has the following technical defects: many layers, long production cycle, low reliability, single working band, and generally low emissivity thin films do not have the characteristics of being insensitive to polarization and incident angle. Summary of the Invention

[0007] The present invention aims to overcome the defects of the prior art and provides a low-layer one-dimensional infrared low-emissivity film structure with fewer layers, shorter production cycle, higher reliability, and the ability to achieve dual-band low emission with polarization and incident angle insensitivity.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0009] The low-layer one-dimensional infrared low-emissivity film structure, which is insensitive to polarization and incident angle, is composed of a one-dimensional λ / 4 periodic photonic crystal structure and a quasi-periodic photonic crystal structure, with the last layer of the one-dimensional λ / 4 periodic photonic crystal structure and the top layer of the quasi-periodic photonic crystal structure bonded together.

[0010] The low-layer, one-dimensional infrared low-emissivity film structure, which is insensitive to polarization and incident angle, is expressed by the following formula:

[0011] (AB) 2 (CD) 5 In equation (1):

[0012] (AB) 2 Describes a one-dimensional λ / 4 periodic photonic crystal structure, where:

[0013] (AB) represents a sub-periodic photonic crystal structure in which Ge and ZnO are arranged in sequence;

[0014] 2 indicates that there are two sub-periodic photonic crystal structures;

[0015] (CD) 5Describes a quasi-periodic photonic crystal structure, wherein:

[0016] (CD) represents a sub-quasi-periodic photonic crystal structure in which Ge and ZnO are arranged in sequence;

[0017] 5 indicates that there are 5 sub-quasi-periodic photonic crystal structures.

[0018] The A indicates that the material is Ge and the thickness is 200-250 nm.

[0019] The B indicates that the material is ZnO with a thickness of 500–550 nm.

[0020] The C indicates that the material is Ge, with a thickness of 600–900 nm.

[0021] The D indicates that the material is ZnO with a thickness of 1100–1800 nm.

[0022] The total number of layers in the low-layer one-dimensional infrared low-emissivity film system is 14; among them, the number of layers in the one-dimensional λ / 4 periodic photonic crystal structure is 4, and the number of layers in the quasi-periodic photonic crystal structure is 10.

[0023] The one-dimensional λ / 4 periodic photonic crystal structure consists of two sub-periodic photonic crystal structures. The first sub-periodic photonic crystal structure is composed of a first Ge1 layer and a second ZnO1 layer, and the second sub-periodic photonic crystal structure is composed of a third Ge2 layer and a fourth ZnO2 layer. The thicknesses of the Ge1, ZnO1, Ge2, and ZnO2 layers are 200–250 nm, 500–550 nm, 220–250 nm, and 500–550 nm, respectively. The sum of the thicknesses of the Ge1 and ZnO2 layers in the first sub-periodic photonic crystal structure is 700–800 nm, and the sum of the thicknesses of the Ge1, ZnO1, Ge2, and ZnO2 layers in the two sub-periodic photonic crystal structures is 1420–1600 nm.

[0024] The four layers of the one-dimensional λ / 4 periodic photonic crystal structure are formed by stacking the first, second, third, and fourth layers from top to bottom in that order.

[0025] The quasi-periodic photonic crystal structure consists of five sub-quasi-periodic photonic crystal structures. The first sub-quasi-periodic photonic crystal structure is composed of a Ge3 layer (layer 5) and a ZnO3 layer (layer 6). The second sub-quasi-periodic photonic crystal structure is composed of a Ge4 layer (layer 7) and a ZnO4 layer (layer 8). The third sub-quasi-periodic photonic crystal structure is composed of a Ge5 layer (layer 9) and a ZnO5 layer (layer 10). The fourth sub-quasi-periodic photonic crystal structure is composed of a Ge6 layer (layer 11) and a ZnO6 layer (layer 12). The fifth sub-quasi-periodic photonic crystal structure is composed of a Ge7 layer (layer 13) and a ZnO7 layer (layer 14). The thicknesses of the Ge3 layer, ZnO3 layer, Ge4 layer, ZnO4 layer, ..., Ge7 layer and ZnO7 layer are 600–700 nm, 1100–1200 nm, 700–740 nm, 1200–1250 nm, 750–780 nm, 1300 nm, 800–830 nm, 1450–1500 nm, 850–900 nm, and 1600–1800 nm, respectively. The sum of the thicknesses of the Ge3 layer and ZnO3 layer in the one sub-quasi-periodic photonic crystal structure is 1700–1900 nm, and the sum of the thicknesses of the Ge3 layer, ZnO3 layer, Ge4 layer, ZnO4 layer, ..., Ge7 layer and ZnO7 layer in the five sub-quasi-periodic photonic crystal structures is 10350–11000 nm.

[0026] The 10 layers of the quasi-periodic photonic crystal structure are formed by stacking layers 5, 6, 7, ..., 14 from top to bottom.

[0027] The low-layer one-dimensional infrared low-emissivity film structure, when the incident light angle is 0–60°:

[0028] When TE polarized, an average emissivity of 0.018–0.045 can be achieved in the 3–5 μm range, and an average emissivity of 0.024–0.054 can be achieved in the 8–14 μm range.

[0029] When TM polarized, an average emissivity of 0.025–0.130 can be achieved in the 3–5 μm range, and an average emissivity of 0.040–0.080 can be achieved in the 8–14 μm range.

[0030] By adopting the above technical solution, the present invention has the following advantages compared with the prior art:

[0031] The one-dimensional λ / 4 periodic photonic crystal structure in this invention is composed of a semiconductor material (Ge, with a refractive index of about 4.2) and an oxide material (ZnO, with a refractive index of about 1.7). The sum of the thicknesses of the Ge layer and the ZnO layer in a sub-periodic photonic crystal structure is 700-800 nm. The one-dimensional λ / 4 periodic photonic crystal structure has 4 layers, achieving a low emissivity in the mid-infrared band of 3-5 μm using a relatively small number of thin film layers.

[0032] The quasi-periodic photonic crystal structure in this invention is composed of a semiconductor material (Ge, with a refractive index of approximately 4.2) and an oxide material (ZnO, with a refractive index of approximately 1.7). The sum of the thicknesses of the Ge and ZnO layers in a sub-quasi-periodic photonic crystal structure is between 1700 and 2700 nm. The quasi-periodic photonic crystal structure has 10 layers, which is a small number. It can achieve low emissivity in the 8-14 μm far-infrared band while being compatible with low emissivity in the 3-5 μm mid-infrared band, thus further realizing dual-band low emissivity.

[0033] The low-layer one-dimensional infrared low-emissivity film system in this invention has 14 layers, which can shorten the production cycle of the coating process, reduce production costs, and improve product reliability.

[0034] According to the electromagnetic field simulation software CST, when the incident light angle is 0-60°, the TE polarization can achieve an average emissivity between 0.018 and 0.045 in 3-5 μm, and an average emissivity between 0.024 and 0.054 in 8-14 μm; the TM polarization can achieve an average emissivity between 0.025 and 0.130 in 3-5 μm; and an average emissivity between 0.040 and 0.080 in 8-14 μm, thus achieving polarization insensitivity to the incident angle.

[0035] Therefore, the present invention has the characteristics of fewer layers, shorter production cycle, higher reliability, and the ability to achieve dual-band low emission and insensitivity to polarization and incident angle. Attached Figure Description

[0036] Figure 1 The infrared reflectance spectrum of incident light when incident in the positive direction is shown for a low-layer one-dimensional infrared low-emissivity film structure that is insensitive to polarization and incident angle according to the present invention.

[0037] Figure 2 for Figure 1 The infrared emissivity spectrum of incident light when incident in the positive direction is shown for a low-layer one-dimensional infrared low-emissivity film structure whose polarization is insensitive to the incident angle. Detailed Implementation

[0038] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit its scope of use.

[0039] A low-layer-number, one-dimensional infrared low-emissivity film structure that is insensitive to polarization and incident angle.

[0040] The low-layer one-dimensional infrared low-emissivity film structure, which is insensitive to polarization and incident angle, is composed of a one-dimensional λ / 4 periodic photonic crystal structure and a quasi-periodic photonic crystal structure, with the last layer of the one-dimensional λ / 4 periodic photonic crystal structure and the top layer of the quasi-periodic photonic crystal structure bonded together.

[0041] The low-layer, one-dimensional infrared low-emissivity film structure, which is insensitive to polarization and incident angle, is expressed by the following formula:

[0042] (AB) 2 (CD) 5 In equation (1):

[0043] (AB) 2 Describes a one-dimensional λ / 4 periodic photonic crystal structure, where:

[0044] (AB) represents a sub-periodic photonic crystal structure in which Ge and ZnO are arranged in sequence;

[0045] 2 indicates that there are two sub-periodic photonic crystal structures;

[0046] (CD) 5 Describes a quasi-periodic photonic crystal structure, wherein:

[0047] (CD) represents a sub-quasi-periodic photonic crystal structure in which Ge and ZnO are arranged in sequence;

[0048] 5 indicates that there are 5 sub-quasi-periodic photonic crystal structures.

[0049] The A indicates that the material is Ge and the thickness is 200-250 nm.

[0050] The B indicates that the material is ZnO with a thickness of 500–550 nm.

[0051] The C indicates that the material is Ge, with a thickness of 600–900 nm.

[0052] The D indicates that the material is ZnO with a thickness of 1100–1800 nm.

[0053] The total number of layers in the low-layer one-dimensional infrared low-emissivity film system is 14; among them, the number of layers in the one-dimensional λ / 4 periodic photonic crystal structure is 4, and the number of layers in the quasi-periodic photonic crystal structure is 10.

[0054] The one-dimensional λ / 4 periodic photonic crystal structure consists of two sub-periodic photonic crystal structures. The first sub-periodic photonic crystal structure consists of a first Ge1 layer and a second ZnO1 layer, and the second sub-periodic photonic crystal structure consists of a third Ge2 layer and a fourth ZnO2 layer. The thicknesses of the Ge1, ZnO1, Ge2, and ZnO2 layers are 200–250 nm, 500–550 nm, 220–250 nm, and 500–550 nm, respectively. The sum of the thicknesses of the Ge1 and ZnO2 layers in the first sub-periodic photonic crystal structure is 700–800 nm, and the sum of the thicknesses of the Ge1, ZnO1, Ge2, and ZnO2 layers in the two sub-periodic photonic crystal structures is 1420–1600 nm.

[0055] The four layers of the one-dimensional λ / 4 periodic photonic crystal structure are formed by stacking the first, second, third, and fourth layers from top to bottom in that order.

[0056] The quasi-periodic photonic crystal structure consists of five sub-quasi-periodic photonic crystal structures. The first sub-quasi-periodic photonic crystal structure is composed of a Ge3 layer (layer 5) and a ZnO3 layer (layer 6). The second sub-quasi-periodic photonic crystal structure is composed of a Ge4 layer (layer 7) and a ZnO4 layer (layer 8). The third sub-quasi-periodic photonic crystal structure is composed of a Ge5 layer (layer 9) and a ZnO5 layer (layer 10). The fourth sub-quasi-periodic photonic crystal structure is composed of a Ge6 layer (layer 11) and a ZnO6 layer (layer 12). The fifth sub-quasi-periodic photonic crystal structure is composed of a Ge7 layer (layer 13) and a ZnO7 layer (layer 14). The thicknesses of the Ge3, ZnO3, Ge4, ZnO4, ..., Ge7, and ZnO7 layers are 600–700 nm, 1100–1200 nm, 700–740 nm, 1200–1250 nm, 750–780 nm, 1300 nm, 800–830 nm, 1450–1500 nm, 850–900 nm, and 1600–1800 nm, respectively. The sum of the thicknesses of the Ge3 and ZnO3 layers in the first sub-quasi-periodic photonic crystal structure is 1700–1900 nm, and the sum of the thicknesses of the Ge3, ZnO3, Ge4, ZnO4, ..., Ge7, and ZnO7 layers in the five sub-quasi-periodic photonic crystal structures is 10350–11000 nm.

[0057] The 10 layers of the quasi-periodic photonic crystal structure are formed by stacking layers 5, 6, 7, ..., 14 from top to bottom.

[0058] The low-layer one-dimensional infrared low-emissivity film structure, when the incident light angle is 0–60°:

[0059] When TE polarized, an average emissivity of 0.018–0.045 can be achieved in the 3–5 μm range, and an average emissivity of 0.024–0.054 can be achieved in the 8–14 μm range.

[0060] When TM polarized, an average emissivity of 0.025–0.130 can be achieved in the 3–5 μm range, and an average emissivity of 0.040–0.080 can be achieved in the 8–14 μm range.

[0061] Example 1

[0062] A low-layer-number, one-dimensional infrared low-emissivity film structure that is insensitive to polarization and incident angle. The film structure described in this embodiment is:

[0063] The low-layer one-dimensional infrared low-emissivity film structure, which is insensitive to polarization and incident angle, is composed of a one-dimensional λ / 4 periodic photonic crystal structure and a quasi-periodic photonic crystal structure, with the last layer of the one-dimensional λ / 4 periodic photonic crystal structure and the top layer of the quasi-periodic photonic crystal structure bonded together.

[0064] The low-layer, one-dimensional infrared low-emissivity film structure, which is insensitive to polarization and incident angle, is expressed by the following formula:

[0065] (AB) 2 (CD) 5 In equation (1):

[0066] (AB) 2 Describes a one-dimensional λ / 4 periodic photonic crystal structure, where:

[0067] (AB) represents a sub-periodic photonic crystal structure in which Ge and ZnO are arranged in sequence;

[0068] 2 indicates that there are two sub-periodic photonic crystal structures;

[0069] (CD) 5 Describes a quasi-periodic photonic crystal structure, wherein:

[0070] (CD) represents a sub-quasi-periodic photonic crystal structure in which Ge and ZnO are arranged in sequence;

[0071] 5 indicates that there are 5 sub-quasi-periodic photonic crystal structures.

[0072] The A indicates that the material is Ge and the thickness is 220 nm.

[0073] The B indicates that the material is ZnO with a thickness of 520 nm.

[0074] The C indicates that the material is Ge and the thickness is 650 nm.

[0075] The D indicates that the material is ZnO with a thickness of 1200 nm.

[0076] The total number of layers in the low-layer one-dimensional infrared low-emissivity film system is 14; among them, the number of layers in the one-dimensional λ / 4 periodic photonic crystal structure is 4, and the number of layers in the quasi-periodic photonic crystal structure is 10.

[0077] The one-dimensional λ / 4 periodic photonic crystal structure consists of two sub-periodic photonic crystal structures. The first sub-periodic photonic crystal structure is composed of a first Ge1 layer and a second ZnO1 layer, and the second sub-periodic photonic crystal structure is composed of a third Ge2 layer and a fourth ZnO2 layer. The thicknesses of the Ge1, ZnO1, Ge2, and ZnO2 layers are 220 nm, 520 nm, 220 nm, and 520 nm, respectively. The sum of the thicknesses of the Ge1 and ZnO2 layers in the first sub-periodic photonic crystal structure is 740 nm, and the sum of the thicknesses of the Ge1, ZnO1, Ge2, and ZnO2 layers in the two sub-periodic photonic crystal structures is 1480 nm.

[0078] The four layers of the one-dimensional λ / 4 periodic photonic crystal structure are formed by stacking the first, second, third, and fourth layers from top to bottom in that order.

[0079] The quasi-periodic photonic crystal structure consists of five sub-quasi-periodic photonic crystal structures. The first sub-quasi-periodic photonic crystal structure is composed of a Ge3 layer (layer 5) and a ZnO3 layer (layer 6). The second sub-quasi-periodic photonic crystal structure is composed of a Ge4 layer (layer 7) and a ZnO4 layer (layer 8). The third sub-quasi-periodic photonic crystal structure is composed of a Ge5 layer (layer 9) and a ZnO5 layer (layer 10). The fourth sub-quasi-periodic photonic crystal structure is composed of a Ge6 layer (layer 11) and a ZnO6 layer (layer 12). The fifth sub-quasi-periodic photonic crystal structure is composed of a Ge7 layer (layer 13) and a ZnO7 layer (layer 14). The thicknesses of the Ge3, ZnO3, Ge4, ZnO4, ..., Ge7, and ZnO7 layers are 650 nm, 1200 nm, 700 nm, 1250 nm, 750 nm, 1300 nm, 800 nm, 1500 nm, 900 nm, and 1800 nm, respectively. The sum of the thicknesses of the Ge3 and ZnO3 layers in the first sub-quasi-periodic photonic crystal structure is 1850 nm, and the sum of the thicknesses of the Ge3, ZnO3, Ge4, ZnO4, ..., Ge7, and ZnO7 layers in the five sub-quasi-periodic photonic crystal structures is 10850 nm.

[0080] The 10 layers of the quasi-periodic photonic crystal structure are formed by stacking layers 5, 6, 7, ..., 14 from top to bottom.

[0081] The low-layer one-dimensional infrared low-emissivity film structure, when the incident light angle is 0–60°:

[0082] When TE polarized, an average emissivity of 0.020–0.026 can be achieved in the 3–5 μm range, and an average emissivity of 0.027–0.040 can be achieved in the 8–14 μm range.

[0083] When TM polarized, an average emissivity of 0.025–0.125 can be achieved in the 3–5 μm range, and an average emissivity of 0.040–0.072 can be achieved in the 8–14 μm range.

[0084] Example 2

[0085] A low-layer-number, one-dimensional infrared low-emissivity film structure that is insensitive to polarization and incident angle. The film structure described in this embodiment is:

[0086] The low-layer one-dimensional infrared low-emissivity film structure, which is insensitive to polarization and incident angle, is composed of a one-dimensional λ / 4 periodic photonic crystal structure and a quasi-periodic photonic crystal structure, with the last layer of the one-dimensional λ / 4 periodic photonic crystal structure and the top layer of the quasi-periodic photonic crystal structure bonded together.

[0087] The low-layer, one-dimensional infrared low-emissivity film structure, which is insensitive to polarization and incident angle, is expressed by the following formula:

[0088] (AB) 2 (CD) 5 In equation (1):

[0089] (AB) 2 Describes a one-dimensional λ / 4 periodic photonic crystal structure, where:

[0090] (AB) represents a sub-periodic photonic crystal structure in which Ge and ZnO are arranged in sequence;

[0091] 2 indicates that there are two sub-periodic photonic crystal structures;

[0092] (CD) 5 Describes a quasi-periodic photonic crystal structure, wherein:

[0093] (CD) represents a sub-quasi-periodic photonic crystal structure in which Ge and ZnO are arranged in sequence;

[0094] 5 indicates that there are 5 sub-quasi-periodic photonic crystal structures.

[0095] The A indicates that the material is Ge and the thickness is 200 nm.

[0096] The B indicates that the material is ZnO with a thickness of 500 nm.

[0097] The C indicates that the material is Ge and the thickness is 700 nm.

[0098] The D indicates that the material is ZnO with a thickness of 1100 nm.

[0099] The total number of layers in the low-layer one-dimensional infrared low-emissivity film system is 14; among them, the number of layers in the one-dimensional λ / 4 periodic photonic crystal structure is 4, and the number of layers in the quasi-periodic photonic crystal structure is 10.

[0100] The one-dimensional λ / 4 periodic photonic crystal structure consists of two sub-periodic photonic crystal structures. The first sub-periodic photonic crystal structure is composed of a first Ge1 layer and a second ZnO1 layer, and the second sub-periodic photonic crystal structure is composed of a third Ge2 layer and a fourth ZnO2 layer. The thicknesses of the Ge1, ZnO1, Ge2, and ZnO2 layers are 200 nm, 500 nm, 220 nm, and 500 nm, respectively. The sum of the thicknesses of the Ge1 and ZnO2 layers in the first sub-periodic photonic crystal structure is 700 nm, and the sum of the thicknesses of the Ge1, ZnO1, Ge2, and ZnO2 layers in the two sub-periodic photonic crystal structures is 1420 nm.

[0101] The four layers of the one-dimensional λ / 4 periodic photonic crystal structure are formed by stacking the first, second, third, and fourth layers from top to bottom in that order.

[0102] The quasi-periodic photonic crystal structure consists of five sub-quasi-periodic photonic crystal structures. The first sub-quasi-periodic photonic crystal structure is composed of a Ge3 layer (layer 5) and a ZnO3 layer (layer 6). The second sub-quasi-periodic photonic crystal structure is composed of a Ge4 layer (layer 7) and a ZnO4 layer (layer 8). The third sub-quasi-periodic photonic crystal structure is composed of a Ge5 layer (layer 9) and a ZnO5 layer (layer 10). The fourth sub-quasi-periodic photonic crystal structure is composed of a Ge6 layer (layer 11) and a ZnO6 layer (layer 12). The fifth sub-quasi-periodic photonic crystal structure is composed of a Ge7 layer (layer 13) and a ZnO7 layer (layer 14). The thicknesses of the Ge3, ZnO3, Ge4, ZnO4, ..., Ge7, and ZnO7 layers are 700 nm, 1100 nm, 740 nm, 1200 nm, 770 nm, 1300 nm, 810 nm, 1500 nm, 850 nm, and 1600 nm, respectively. The sum of the thicknesses of the Ge3 and ZnO3 layers in the first sub-quasi-periodic photonic crystal structure is 1800 nm, and the sum of the thicknesses of the Ge3, ZnO3, Ge4, ZnO4, ..., Ge7, and ZnO7 layers in the five sub-quasi-periodic photonic crystal structures is 10570 nm.

[0103] The 10 layers of the quasi-periodic photonic crystal structure are formed by stacking layers 5, 6, 7, ..., 14 from top to bottom.

[0104] The low-layer one-dimensional infrared low-emissivity film structure, when the incident light angle is 0–60°:

[0105] When TE polarized, an average emissivity of 0.021–0.034 can be achieved in the 3–5 μm range, and an average emissivity of 0.024–0.044 can be achieved in the 8–14 μm range.

[0106] When TM polarized, an average emissivity of 0.034–0.125 can be achieved in the 3–5 μm range, and an average emissivity of 0.045–0.077 can be achieved in the 8–14 μm range.

[0107] Example 3

[0108] A low-layer-number, one-dimensional infrared low-emissivity film structure that is insensitive to polarization and incident angle. The film structure described in this embodiment is:

[0109] The low-layer one-dimensional infrared low-emissivity film structure, which is insensitive to polarization and incident angle, is composed of a one-dimensional λ / 4 periodic photonic crystal structure and a quasi-periodic photonic crystal structure, with the last layer of the one-dimensional λ / 4 periodic photonic crystal structure and the top layer of the quasi-periodic photonic crystal structure bonded together.

[0110] The low-layer, one-dimensional infrared low-emissivity film structure, which is insensitive to polarization and incident angle, is expressed by the following formula:

[0111] (AB) 2 (CD) 5 In equation (1):

[0112] (AB) 2 Describes a one-dimensional λ / 4 periodic photonic crystal structure, where:

[0113] (AB) represents a sub-periodic photonic crystal structure in which Ge and ZnO are arranged in sequence;

[0114] 2 indicates that there are two sub-periodic photonic crystal structures;

[0115] (CD) 5 Describes a quasi-periodic photonic crystal structure, wherein:

[0116] (CD) represents a sub-quasi-periodic photonic crystal structure in which Ge and ZnO are arranged in sequence;

[0117] 5 indicates that there are 5 sub-quasi-periodic photonic crystal structures.

[0118] The A indicates that the material is Ge and the thickness is 230 nm.

[0119] The B indicates that the material is ZnO with a thickness of 540 nm.

[0120] The C indicates that the material is Ge and the thickness is 600 nm.

[0121] The D indicates that the material is ZnO with a thickness of 1100 nm.

[0122] The total number of layers in the low-layer one-dimensional infrared low-emissivity film system is 14; among them, the number of layers in the one-dimensional λ / 4 periodic photonic crystal structure is 4, and the number of layers in the quasi-periodic photonic crystal structure is 10.

[0123] The one-dimensional λ / 4 periodic photonic crystal structure consists of two sub-periodic photonic crystal structures. The first sub-periodic photonic crystal structure is composed of a first Ge1 layer and a second ZnO1 layer, and the second sub-periodic photonic crystal structure is composed of a third Ge2 layer and a fourth ZnO2 layer. The thicknesses of the Ge1, ZnO1, Ge2, and ZnO2 layers are 230 nm, 540 nm, 230 nm, and 540 nm, respectively. The sum of the thicknesses of the Ge1 and ZnO2 layers in the first sub-periodic photonic crystal structure is 770 nm, and the sum of the thicknesses of the Ge1, ZnO1, Ge2, and ZnO2 layers in the two sub-periodic photonic crystal structures is 1540 nm.

[0124] The four layers of the one-dimensional λ / 4 periodic photonic crystal structure are formed by stacking the first, second, third, and fourth layers from top to bottom in that order.

[0125] The quasi-periodic photonic crystal structure consists of five sub-quasi-periodic photonic crystal structures. The first sub-quasi-periodic photonic crystal structure is composed of a Ge3 layer (layer 5) and a ZnO3 layer (layer 6). The second sub-quasi-periodic photonic crystal structure is composed of a Ge4 layer (layer 7) and a ZnO4 layer (layer 8). The third sub-quasi-periodic photonic crystal structure is composed of a Ge5 layer (layer 9) and a ZnO5 layer (layer 10). The fourth sub-quasi-periodic photonic crystal structure is composed of a Ge6 layer (layer 11) and a ZnO6 layer (layer 12). The fifth sub-quasi-periodic photonic crystal structure is composed of a Ge7 layer (layer 13) and a ZnO7 layer (layer 14). The thicknesses of the Ge3, ZnO3, Ge4, ZnO4, ..., Ge7, and ZnO7 layers are 600 nm, 1100 nm, 720 nm, 1200 nm, 780 nm, 1300 nm, 830 nm, 1500 nm, 850 nm, and 1700 nm, respectively. The sum of the thicknesses of the Ge3 and ZnO3 layers in the first sub-quasi-periodic photonic crystal structure is 1700 nm, and the sum of the thicknesses of the Ge3, ZnO3, Ge4, ZnO4, ..., Ge7, and ZnO7 layers in the five sub-quasi-periodic photonic crystal structures is 10580 nm.

[0126] The 10 layers of the quasi-periodic photonic crystal structure are formed by stacking layers 5, 6, 7, ..., 14 from top to bottom.

[0127] The low-layer one-dimensional infrared low-emissivity film structure, when the incident light angle is 0–60°:

[0128] When TE polarized, an average emissivity of 0.020–0.039 can be achieved in the 3–5 μm range, and an average emissivity of 0.026–0.045 can be achieved in the 8–14 μm range.

[0129] When TM polarized, an average emissivity of 0.039–0.130 can be achieved in the 3–5 μm range, and an average emissivity of 0.045–0.077 can be achieved in the 8–14 μm range.

[0130] Example 4

[0131] A low-layer-number, one-dimensional infrared low-emissivity film structure that is insensitive to polarization and incident angle. The film structure described in this embodiment is:

[0132] The low-layer one-dimensional infrared low-emissivity film structure, which is insensitive to polarization and incident angle, is composed of a one-dimensional λ / 4 periodic photonic crystal structure and a quasi-periodic photonic crystal structure, with the last layer of the one-dimensional λ / 4 periodic photonic crystal structure and the top layer of the quasi-periodic photonic crystal structure bonded together.

[0133] The low-layer, one-dimensional infrared low-emissivity film structure, which is insensitive to polarization and incident angle, is expressed by the following formula:

[0134] (AB) 2 (CD) 5 In equation (1):

[0135] (AB) 2 Describes a one-dimensional λ / 4 periodic photonic crystal structure, where:

[0136] (AB) represents a sub-periodic photonic crystal structure in which Ge and ZnO are arranged in sequence;

[0137] 2 indicates that there are two sub-periodic photonic crystal structures;

[0138] (CD) 5 Describes a quasi-periodic photonic crystal structure, wherein:

[0139] (CD) represents a sub-quasi-periodic photonic crystal structure in which Ge and ZnO are arranged in sequence;

[0140] 5 indicates that there are 5 sub-quasi-periodic photonic crystal structures.

[0141] The A indicates that the material is Ge and the thickness is 250 nm.

[0142] The B indicates that the material is ZnO with a thickness of 550 nm.

[0143] The C indicates that the material is Ge and the thickness is 600 nm.

[0144] The D indicates that the material is ZnO with a thickness of 1100 nm.

[0145] The total number of layers in the low-layer one-dimensional infrared low-emissivity film system is 14; among them, the number of layers in the one-dimensional λ / 4 periodic photonic crystal structure is 4, and the number of layers in the quasi-periodic photonic crystal structure is 10.

[0146] The one-dimensional λ / 4 periodic photonic crystal structure consists of two sub-periodic photonic crystal structures. The first sub-periodic photonic crystal structure is composed of a first Ge1 layer and a second ZnO1 layer, and the second sub-periodic photonic crystal structure is composed of a third Ge2 layer and a fourth ZnO2 layer. The thicknesses of the Ge1, ZnO1, Ge2, and ZnO2 layers are 250 nm, 550 nm, 250 nm, and 550 nm, respectively. The sum of the thicknesses of the Ge1 and ZnO2 layers in the first sub-periodic photonic crystal structure is 800 nm, and the sum of the thicknesses of the Ge1, ZnO1, Ge2, and ZnO2 layers in the two sub-periodic photonic crystal structures is 1600 nm.

[0147] The four layers of the one-dimensional λ / 4 periodic photonic crystal structure are formed by stacking the first, second, third, and fourth layers from top to bottom in that order.

[0148] The quasi-periodic photonic crystal structure consists of five sub-quasi-periodic photonic crystal structures. The first sub-quasi-periodic photonic crystal structure is composed of a Ge3 layer (layer 5) and a ZnO3 layer (layer 6). The second sub-quasi-periodic photonic crystal structure is composed of a Ge4 layer (layer 7) and a ZnO4 layer (layer 8). The third sub-quasi-periodic photonic crystal structure is composed of a Ge5 layer (layer 9) and a ZnO5 layer (layer 10). The fourth sub-quasi-periodic photonic crystal structure is composed of a Ge6 layer (layer 11) and a ZnO6 layer (layer 12). The fifth sub-quasi-periodic photonic crystal structure is composed of a Ge7 layer (layer 13) and a ZnO7 layer (layer 14). The thicknesses of the Ge3, ZnO3, Ge4, ZnO4, ..., Ge7, and ZnO7 layers are 600 nm, 1100 nm, 720 nm, 1200 nm, 780 nm, 1300 nm, 830 nm, 1450 nm, 880 nm, and 1650 nm, respectively. The sum of the thicknesses of the Ge3 and ZnO3 layers in the first sub-quasi-periodic photonic crystal structure is 1700 nm, and the sum of the thicknesses of the Ge3, ZnO3, Ge4, ZnO4, ..., Ge7, and ZnO7 layers in the five sub-quasi-periodic photonic crystal structures is 10510 nm.

[0149] The 10 layers of the quasi-periodic photonic crystal structure are formed by stacking layers 5, 6, 7, ..., 14 from top to bottom.

[0150] The low-layer one-dimensional infrared low-emissivity film structure, when the incident light angle is 0–60°:

[0151] When TE polarized, an average emissivity of 0.020–0.039 can be achieved in the 3–5 μm range, and an average emissivity of 0.024–0.054 can be achieved in the 8–14 μm range.

[0152] When TM polarized, an average emissivity of 0.039–0.130 can be achieved in the 3–5 μm range, and an average emissivity of 0.054–0.080 can be achieved in the 8–14 μm range.

[0153] The one-dimensional λ / 4 periodic photonic crystal structure in this specific embodiment is composed of a semiconductor material (Ge, with a refractive index of approximately 4.2) and an oxide material (ZnO, with a refractive index of approximately 1.7). The sum of the thicknesses of the Ge layer and the ZnO layer in a sub-periodic photonic crystal structure is 700–800 nm. The one-dimensional λ / 4 periodic photonic crystal structure has 4 layers, achieving a low emissivity in the mid-infrared band of 3–5 μm using a relatively small number of thin film layers.

[0154] The quasi-periodic photonic crystal structure in this specific embodiment is composed of a semiconductor material (Ge, with a refractive index of approximately 4.2) and an oxide material (ZnO, with a refractive index of approximately 1.7). The combined thickness of the Ge and ZnO layers in a sub-quasi-periodic photonic crystal structure is between 1700 and 2700 nm. The quasi-periodic photonic crystal structure has 10 layers, a low number that allows it to achieve low emissivity in both the 3–5 μm mid-infrared band and the 8–14 μm far-infrared band, further realizing dual-band low emission. The low-layer, one-dimensional infrared low-emissivity film structure with polarization and incident angle insensitivity designed in this specific embodiment is shown in the attached figure. Figure 1 The infrared reflectance spectrum of incident light when incident in the positive direction is shown for a low-layer-number one-dimensional infrared low-emissivity film structure that is insensitive to polarization and incident angle in Example 1. Figure 2 for Figure 1 The infrared emissivity spectrum of incident light in the positive direction for a low-layer-number one-dimensional infrared low-emissivity film structure whose polarization and incident angle are insensitive; from Figure 1 and Figure 2 As can be seen, the low-layer one-dimensional infrared low-emissivity film structure has high infrared reflectivity and low infrared emissivity.

[0155] The low-layer one-dimensional infrared low-emissivity film system in this specific embodiment has 14 layers, which can shorten the production cycle of the coating process, reduce production costs, and improve product reliability.

[0156] This specific implementation was simulated using the electromagnetic field simulation software CST. When the incident angle is 0 to 60°, the TE polarization can achieve an average emissivity between 0.018 and 0.045 in the 3 to 5 μm range, and the TE polarization can achieve an average emissivity between 0.024 and 0.054 in the 8 to 14 μm range; the TM polarization can achieve an average emissivity between 0.025 and 0.130 in the 3 to 5 μm range; and the TM polarization can achieve an average emissivity between 0.040 and 0.080 in the 8 to 14 μm range, thus achieving polarization insensitivity to the incident angle.

[0157] Therefore, this specific implementation has the characteristics of fewer layers, shorter production cycle, higher reliability, and the ability to achieve dual-band low emission and insensitivity to polarization and incident angle.

Claims

1. A low-layer-number, one-dimensional infrared low-emissivity film structure that is insensitive to polarization and incident angle, characterized in that: The low-layer one-dimensional infrared low-emissivity film structure that is insensitive to polarization and incident angle is composed of a one-dimensional λ / 4 periodic photonic crystal structure and a quasi-periodic photonic crystal structure, with the last layer of the one-dimensional λ / 4 periodic photonic crystal structure and the top layer of the quasi-periodic photonic crystal structure bonded together. The low-layer, one-dimensional infrared low-emissivity film structure, which is insensitive to polarization and incident angle, is expressed by the following formula: (AB) 2 (CD) 5 (1) In formula (1): (AB) 2 Describes a one-dimensional λ / 4 periodic photonic crystal structure, where: (AB) represents a sub-periodic photonic crystal structure in which Ge and ZnO are arranged in sequence. 2 indicates that there are two sub-periodic photonic crystal structures; (CD) 5 Describes a quasi-periodic photonic crystal structure, wherein: (CD) represents a sub-quasi-periodic photonic crystal structure in which Ge and ZnO are arranged in sequence. 5 indicates that there are 5 sub-quasi-periodic photonic crystal structures; A indicates that the material is Ge and the thickness is 200~250nm; The B indicates that the material is ZnO with a thickness of 500~550nm; The C indicates that the material is Ge, with a thickness of 600~900 nm; The D indicates that the material is ZnO with a thickness of 1100~1800nm.

2. The low-layer-number one-dimensional infrared low-emissivity film structure insensitive to polarization and incident angle according to claim 1, characterized in that, The one-dimensional λ / 4 periodic photonic crystal structure consists of two sub-periodic photonic crystal structures. The first sub-periodic photonic crystal structure consists of a first Ge1 layer and a second ZnO1 layer, and the second sub-periodic photonic crystal structure consists of a third Ge2 layer and a fourth ZnO2 layer. The thicknesses of the Ge1, ZnO1, Ge2, and ZnO2 layers are 200-250 nm, 500-550 nm, 220-250 nm, and 500-550 nm, respectively. The sum of the thicknesses of the Ge1 and ZnO1 layers in the first sub-periodic photonic crystal structure is 700-800 nm, and the sum of the thicknesses of the Ge1, ZnO1, Ge2, and ZnO2 layers in the two sub-periodic photonic crystal structures is 1420-1600 nm. The four layers of the one-dimensional λ / 4 periodic photonic crystal structure are formed by stacking the first, second, third, and fourth layers from top to bottom in that order.

3. The low-layer-number one-dimensional infrared low-emissivity film structure insensitive to polarization and incident angle according to claim 1, characterized in that, The quasi-periodic photonic crystal structure consists of five sub-quasi-periodic photonic crystal structures. The first sub-quasi-periodic photonic crystal structure is composed of a Ge3 layer (layer 5) and a ZnO3 layer (layer 6); the second sub-quasi-periodic photonic crystal structure is composed of a Ge4 layer (layer 7) and a ZnO4 layer (layer 8); the third sub-quasi-periodic photonic crystal structure is composed of a Ge5 layer (layer 9) and a ZnO5 layer (layer 10); the fourth sub-quasi-periodic photonic crystal structure is composed of a Ge6 layer (layer 11) and a ZnO6 layer (layer 12); and the fifth sub-quasi-periodic photonic crystal structure is composed of a Ge7 layer (layer 13) and a ZnO7 layer (layer 14); ... Ge3 layer, ZnO3 layer, Ge4 layer, ZnO4 layer, ... The thicknesses of the Ge7 and ZnO7 layers are 600-700 nm, 1100-1200 nm, 700-740 nm, 1200-1250 nm, 750-780 nm, 1300 nm, 800-830 nm, 1450-1500 nm, 850-900 nm, and 1600-1800 nm, respectively; the sum of the thicknesses of the Ge3 and ZnO3 layers in the first sub-quasi-periodic photonic crystal structure is 1700-1900 nm, and the sum of the thicknesses of the Ge3, ZnO3, Ge4, ZnO4, ..., Ge7 and ZnO7 layers in the five sub-quasi-periodic photonic crystal structures is 10350-11000 nm. The 10 layers of the quasi-periodic photonic crystal structure are formed by stacking layers 5, 6, 7, ..., 14 from top to bottom.

4. The low-layer-number one-dimensional infrared low-emissivity film structure insensitive to polarization and incident angle according to claim 1, characterized in that, The low-layer one-dimensional infrared low-emissivity film structure, when the incident light angle is 0~60°: When TE polarized, an average emissivity of 0.018–0.045 can be achieved in the 3–5 μm range, and an average emissivity of 0.024–0.054 can be achieved in the 8–14 μm range. When TM polarized, an average emissivity of 0.025 to 0.130 can be achieved in the 3 to 5 μm range, and an average emissivity of 0.040 to 0.080 can be achieved in the 8 to 14 μm range.

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