Transferable visible-near infrared light absorber and preparation method thereof

Abstract

The invention provides a transferable visible-near infrared light absorber and a preparation method thereof. The visible-near infrared light absorber comprises a packaging layer, a substrate layer, a high-loss metal layer and a transfer layer which are sequentially arranged from bottom to top, the substrate layer comprises a periodically arranged single-layer microsphere array, and microspheres comprise at least one of polystyrene microspheres and silicon dioxide microspheres; the substrate layer is prepared through colloid self-assembly; the high-loss metal layer comprises high-loss metal columns which are periodically arranged, and the high-loss metal columns comprise at least one of a chromium metal column, a titanium metal column, a tungsten metal column, a nickel metal column, a gold metal column or a silver metal column; and the high-loss metal layer is obtained by performing magnetic control direct current sputtering on high-loss metal on the substrate layer. The visible-near infrared light absorber can be rapidly prepared in a large area through colloid self-assembly and magnetic control direct current sputtering, efficient light absorption is achieved in the visible light-near infrared light frequency band, the absorber is transferred and packaged, and the double-face absorption performance of the absorber can be applied.

Description

Technical Field

[0001] The invention belongs to the technical field of optical devices, and in particular relates to a transferable visible-near infrared light absorber and a preparation method thereof. Background Art

[0002] The solar energy on the earth's surface is mainly concentrated in the visible-near infrared band. Therefore, electromagnetic absorbers with high absorption rates in the visible-near infrared band can effectively absorb solar energy and play an important role in the fields of solar photovoltaics, photoelectric detection and stray light elimination. The physical properties of natural solid materials are mainly determined by the arrangement of their atoms and molecules. Their properties are single and it is difficult to efficiently absorb electromagnetic waves of any band. Metamaterials refer to composite materials with periodic or quasi-periodic structures that are artificially processed. Their physical properties can be customized by designing the period, arrangement, unit size, etc. of the structure. By adjusting the response between the structure and the electromagnetic wave, metamaterials can achieve arbitrary regulation of electromagnetic waves and are a promising candidate material for electromagnetic absorbers.

[0003] With the development of micro-nano preparation technology, metamaterial absorbers have developed rapidly in terms of absorption band and absorption bandwidth: the absorption band has expanded from the original microwave band to high-frequency bands such as near-infrared band and visible light band; the absorption band has developed from the original single-band narrow-band absorption to multi-band absorption and broadband absorption. By designing the micro-nano structural unit of the metamaterial absorber, efficient absorption of electromagnetic waves of any band can be achieved. At present, many types of metamaterial absorbers have been proposed for absorbing electromagnetic waves in the visible-near infrared band, such as metamaterial absorbers with periodic nanodisk arrays (International Journal of Heat and Mass Transfer, Vol. 182, p. 122039) and metamaterial absorbers with periodic nanosquare disk arrays (Nanophotonics, Vol. 12, p. 2461). However, the preparation of the micro-nano arrays of these metamaterial absorbers is complicated, usually relying on expensive top-down technologies such as focused ion beam, electron beam lithography or high-resolution lithography, and the substrate layer needs to be set on a glass substrate, which is difficult to peel off from the glass substrate. There are inherent limitations in terms of production area and device flexibility. The precise micro-nano structure of the metamaterial absorber has low yield and poor flexibility, which limits the production and application of the metamaterial absorber. Therefore, designing a visible-near infrared metamaterial absorber that can be prepared on a large area and can be flexibly transferred has very important practical significance and application value for solving the problems of high preparation cost and difficult transfer application of metamaterial absorbers. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings and deficiencies in the prior art and provide a transferable visible-near-infrared light absorber that can be quickly prepared on a large area through colloidal self-assembly and magnetron DC sputtering. Thanks to the simple and separate structural units of the substrate layer and the high-loss metal layer in the visible-near-infrared light absorber, the substrate layer and the high-loss metal layer can be transferred using a transfer layer, making the visible-near-infrared light absorber easy to transfer, thereby enabling the double-sided absorption performance of the visible-near-infrared light absorber to be used in a variety of application scenarios, achieving broadband high absorption of light in the visible-near-infrared light frequency band.

[0005] The present invention is achieved through the following technical solutions:

[0006] A transferable visible-near infrared light absorber comprises an encapsulation layer, a base layer, a high-loss metal layer and a transfer layer which are arranged in sequence from bottom to top; the base layer comprises a periodically arranged single-layer microsphere array, the single-layer microsphere array comprises at least one of polystyrene microspheres and silica microspheres, wherein the single-layer microsphere array is prepared by a colloidal self-assembly method, and there are gaps between the microspheres of the single-layer microsphere array; the high-loss metal layer comprises periodically arranged high-loss metal columns, the high-loss metal columns comprise at least one of chromium metal columns, titanium metal columns, tungsten metal columns, nickel metal columns, gold metal columns or silver metal columns; the high-loss metal layer is obtained by magnetron direct current sputtering of high-loss metal on the base layer; the transfer layer is adhered to a side of the high-loss metal layer away from the base layer; the encapsulation layer is adhered to one side of the base layer.

[0007] The present invention provides a transferable visible-near infrared light absorber, which is prepared by colloidal self-assembly to form a periodically arranged substrate layer, and high-loss metal columns are formed on the substrate layer by magnetron direct current sputtering, so as to realize the preparation of a large-area visible-near infrared light absorber; the transfer layer is attached to the high-loss metal layer, so that the substrate layer and the high-loss metal columns can be transferred; the encapsulation layer is attached to one side of the substrate layer, and the protective device can be encapsulated; the substrate layer with a low refractive index is limited, so that the incident light generates plasmon resonance and magnetic polaritons with the periodic metal ball top structure on the front of the high-loss metal layer and the periodic metal ball bowl structure on the back of the high-loss metal layer, respectively, so that the high-loss metal layer can absorb visible light and near-infrared light on both sides. The visible-near infrared light absorber provided by the present invention is prepared quickly and in large areas by colloidal self-assembly and magnetron direct current sputtering, and realizes broadband high absorption of light in the frequency band of visible light-near infrared light. The visible-near infrared light absorber can be transferred and encapsulated by the transfer layer and the encapsulation layer, so that its double-sided absorption can be used in a variety of application scenarios.

[0008] Furthermore, the microspheres in the single-layer microsphere array are polystyrene microspheres, and the base layer is prepared by air-liquid interface colloid self-assembly.

[0009] Furthermore, the microspheres in the single-layer microsphere array are silica microspheres, and the base layer is prepared by spin coating.

[0010] Furthermore, in the single-layer microsphere array, the diameter of each microsphere is 400-600 nm. The diameter of the microsphere is controlled to control the size of the high-loss metal layer, so as to achieve efficient absorption of light in the visible light-near infrared light frequency band.

[0011] Furthermore, the period of the single-layer microsphere array is 405-640nm, wherein the period of the single-layer microsphere array is greater than the diameter of the microsphere. The period of the single-layer microsphere array is greater than the diameter of the microsphere, that is, the microspheres are non-densely distributed, which is conducive to forming a high-loss metal column unit with gaps by utilizing the gaps between the microspheres, thereby improving the absorption rate of the incident light.

[0012] Furthermore, the height of the high-loss metal column is 300-700nm. The height of the high-loss metal column is limited to achieve efficient absorption of light in the frequency band of visible light-near infrared light; the high-loss metal column is obtained by magnetron DC sputtering with the substrate layer as a template, and the high-loss metal column is located on each microsphere. Since there are gaps between the microspheres of the substrate layer, non-densely distributed high-loss metal columns are formed, which is conducive to utilizing the gaps between the high-loss metal columns to improve the absorption rate of incident light.

[0013] Furthermore, the transfer layer is a PET tape layer. The transfer layer is used to be attached to the high-loss metal column, thereby transferring the visible-near infrared light absorber. The PET tape has excellent properties of good adhesion, acid and alkali resistance, and high temperature resistance, and plays a role in packaging and protection. At the same time, the use of low-refractive PET tape in the transfer layer is conducive to achieving the double-sided absorption performance of the visible-near infrared light absorber.

[0014] Furthermore, the encapsulation layer is a PET tape layer. The encapsulation layer is used to be attached to the base layer. The PET tape has excellent properties of good adhesion, acid and alkali resistance, and high temperature resistance. The PET tape and the transfer layer are encapsulated together to prevent the visible-near infrared light absorber from directly contacting the external environment, and play a role in transferring, encapsulating, and protecting the absorber. At the same time, the use of low-refractive PET tape in the encapsulation layer is conducive to achieving the double-sided absorption performance of the visible-near infrared light absorber.

[0015] The present invention also provides a method for preparing the above-mentioned transferable visible-near infrared absorber, comprising the following steps: using a colloidal self-assembly method to prepare a periodically arranged single-layer microsphere array, so that there are gaps between the microspheres in the single-layer microsphere array, to obtain a base layer; preparing a high-loss metal layer on the base layer by magnetron DC sputtering; pasting the transfer layer to the side of the high-loss metal layer away from the base layer; pasting the encapsulation layer to the side of the base layer away from the high-loss metal layer, to obtain a visible-near infrared absorber.

[0016] In the method for preparing a transferable visible-near-infrared absorber provided by the present invention, a periodic single-layer microsphere array is formed as a base layer by a colloidal self-assembly method, and a high-loss metal layer with a columnar structure is formed on the base layer by magnetron DC sputtering, thereby realizing large-scale and rapid preparation of the visible-near-infrared absorber, and the transfer layer is adhered to the high-loss metal layer to realize the transfer of the visible-near-infrared absorber, and the encapsulation layer and the transfer layer are used to form an encapsulation of the base layer and the high-loss metal layer.

[0017] Furthermore, in the step of preparing the base layer by using the colloidal self-assembly method, a single-layer microsphere array is prepared by the gas-liquid interface colloidal self-assembly method or the spin coating method; the single-layer microsphere array is transferred and dried to obtain the base layer; in the step of preparing the high-loss metal layer on the base layer by magnetron sputtering, the single-layer microsphere array is placed in a high-vacuum three-target magnetron sputtering coating machine and aligned with the high-loss metal target, argon gas is pumped into the chamber, and the high-loss metal target is sputtered by direct current radio frequency to form periodic high-loss metal columns on the single-layer microsphere array.

[0018] For better understanding and implementation, the present invention is described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a structural model diagram of the visible-near infrared light absorber of Example 2.

[0020] Figure 2 This is a simulated absorption spectrum diagram of the visible-near infrared light absorber of Example 2.

[0021] Figure 3 This is an absorption spectrum diagram of the visible-near infrared light absorber of Example 2.

[0022] Figure 4 It is a schematic diagram of the experimental process of the visible-near infrared light absorber of Example 9.

[0023] Figure 5 This is a flow chart for preparing the visible-near infrared light absorber of Example 9.

[0024] Figure 6 is a scanning electron microscope image of the chromium metal column of Example 10. DETAILED DESCRIPTION

[0025] The embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the embodiments of the present invention, rather than to limit the embodiments of the present invention. It is also necessary to explain that, for ease of description, only parts related to the embodiments of the present invention are shown in the accompanying drawings, rather than all structures.

[0026] Similarly, the terms "fixed" and "connected" used in the specification and claims should not be construed as limited to direct connection. Therefore, the expression "device A is connected to device B" should not be limited to a device or system in which device A is directly connected to device B, but means that there is a path between device A and device B, which may be a path including other devices or tools.

[0027] Example 1

[0028] This embodiment provides a transferable visible-near infrared light absorber, comprising a packaging layer 4, a base layer 1, a high-loss metal layer 2 and a transfer layer 3 arranged in sequence from bottom to top;

[0029] The base layer 1 includes a periodically arranged single-layer microsphere array, wherein the single-layer microsphere array includes at least one of polystyrene microspheres and silica microspheres; wherein the single-layer microsphere array is prepared by a colloidal self-assembly method, and there are gaps between the microspheres of the single-layer microsphere array;

[0030] The high-loss metal layer 2 includes periodically arranged high-loss metal columns, and the high-loss metal columns include at least one of chromium metal columns, titanium metal columns, tungsten metal columns, nickel metal columns, gold metal columns or silver metal columns; the high-loss metal layer 2 is obtained by magnetron DC sputtering of high-loss metal on the base layer 1;

[0031] The transfer layer 3 is adhered to the side of the high-loss metal layer 2 facing away from the base layer 1 .

[0032] The packaging layer 4 is adhered to the side of the substrate layer 1 facing away from the high-loss metal layer 2 .

[0033] In the transferable visible-near-infrared light absorber provided in this embodiment, a periodically arranged substrate layer 1 is prepared by colloidal self-assembly, and a high-loss metal column is formed on the substrate layer 1 by magnetron DC sputtering, thereby realizing the preparation of a large-area visible-near-infrared light absorber; the transfer layer 3 is attached to the high-loss metal layer 2, so that the substrate layer 1 and the high-loss metal column can be transferred; the substrate layer 1 with a low refractive index is limited to make the incident light generate plasmon resonance and magnetic polaritons with the periodic metal ball top structure on the front of the high-loss metal layer and the periodic metal ball bowl structure on the back of the high-loss metal layer, respectively, so that visible light and near-infrared light can be absorbed on both sides. The visible-near-infrared light absorber provided in this embodiment is prepared quickly and on a large scale by colloidal self-assembly and magnetron DC sputtering. The light absorption working part of the visible-near-infrared light absorber is composed of a substrate layer 1 with a period of P and a high-loss metal column layer 2, and broadband high absorption of light is achieved in the visible-near-infrared light frequency band, so that the absorber has excellent double-sided absorption performance. In addition, the transfer layer 3 and the encapsulation layer 4 can realize flexible transfer and encapsulation of the visible-near infrared light absorber.

[0034] Compared with the prior art, the transferable visible-near infrared light absorber provided by the present invention utilizes colloidal self-assembly to prepare a base layer 1, and a high-loss metal column layer 2 is prepared on the base layer 1 by magnetron DC sputtering, thereby forming a bottom-up visible-near infrared light absorber. Since colloidal self-assembly and magnetron sputtering have the advantages of high yield and low cost, the visible-near infrared light absorber can overcome the difficulties of low yield and high cost of most current metamaterial absorbers. The visible-near infrared light absorber can also be flexibly transferred and packaged by the transfer layer 3 and the packaging layer 4, thereby improving the flexibility and stability of the device.

[0035] In this embodiment, the microspheres in the single-layer microsphere array are polystyrene microspheres, and the base layer is prepared by gas-liquid interface colloid self-assembly. The gas-liquid interface colloid self-assembly is used to prepare a periodically arranged single-layer polystyrene microsphere, and there are certain gaps between the single-layer polystyrene microspheres, so that certain gaps are formed between the high-loss metal columns arranged on the polystyrene microspheres, thereby enhancing the absorption of incident light.

[0036] In another embodiment, the microspheres in the single-layer microsphere array are silica microspheres, and the base layer is prepared by spin coating. The spin coating method is used to prepare a periodically arranged single-layer silica microsphere, and there are certain gaps between the single-layer silica microspheres, so that certain gaps are formed between the high-loss metal pillars arranged on the silica microspheres, thereby enhancing the absorption of incident light.

[0037] In this embodiment, in the single-layer microsphere array, the diameter D of each microsphere is 400-600 nm. The diameter D of the microsphere is controlled to control the size L of the high-loss metal layer, so as to achieve efficient absorption of light in the visible light-near infrared light frequency band.

[0038] In this embodiment, the period P of the single-layer microsphere array is 405-640nm, wherein the period P of the single-layer microsphere array is greater than the diameter D of the microsphere. The period P of the single-layer microsphere array is greater than the diameter D of the microsphere, that is, the microspheres are non-densely distributed, which is conducive to forming high-loss metal column units with gaps, and utilizing the gaps between the microspheres to improve the absorption rate of light.

[0039] In this embodiment, the height H of the high-loss metal column is 300-700nm. The height H of the high-loss metal column is limited to achieve efficient absorption of light in the frequency band of visible light-near infrared light; since the high-loss metal column layer 2 is obtained by magnetron DC sputtering with the substrate layer 1 as a template, the high-loss metal column is located on each microsphere, and since there are gaps between the microspheres of the substrate layer 1, a non-densely distributed high-loss metal column layer 2 is formed, which is conducive to utilizing the gaps between the high-loss metal columns to improve the absorption rate of the incident light.

[0040] In this embodiment, the transfer layer 3 is a PET tape layer, which is used to be attached to the high-loss metal column layer 2, so as to transfer the visible-near infrared light absorber. The PET tape has excellent properties of good adhesion, acid and alkali resistance, and high temperature resistance, and plays a role in packaging and protection. At the same time, the use of low-refractive PET tape in the transfer layer 3 is conducive to achieving the double-sided absorption performance of the visible-near infrared light absorber.

[0041] In this embodiment, the visible-near infrared light absorber further includes an encapsulation layer, and the encapsulation layer 4 is arranged on the base layer 1. The PET tape has excellent properties of good adhesion, acid and alkali resistance, and high temperature resistance. The PET tape cooperates with the transfer layer 3 for encapsulation to prevent the visible-near infrared light absorber from direct contact with the external environment, and plays a role in transfer, encapsulation, and protection of the absorber. At the same time, the use of low-refractive PET tape in the encapsulation layer 4 is conducive to achieving the double-sided absorption performance of the visible-near infrared light absorber.

[0042] Example 2

[0043] The present embodiment provides a transferable visible-near infrared light absorber, comprising an encapsulation layer 4, a base layer 1, a high-loss metal layer 2 and a transfer layer 3 arranged in sequence from bottom to top; the base layer 1 comprises a periodically arranged single-layer microsphere array, wherein the single-layer microsphere array is polystyrene microspheres; the base layer 1 is prepared by gas-liquid interface colloid self-assembly;

[0044] The high-loss metal layer 2 includes periodically arranged high-loss metal columns, and the high-loss metal columns include chromium metal columns; the high-loss metal layer 2 is obtained by magnetron DC sputtering of the high-loss metal on the substrate layer 1;

[0045] The transfer layer 3 is a PET tape, which is adhered to the side of the high-loss metal layer 2 facing away from the base layer 1 .

[0046] The packaging layer 4 is a PET tape, which is adhered to the side of the base layer 1 away from the high-loss metal layer 2 .

[0047] In this embodiment, low-refractive-index polystyrene microspheres are conducive to achieving the double-sided absorption of the visible-near-infrared light absorber, and have excellent single-sidedness in the preparation process of the gas-liquid interface colloid self-assembly, and can obtain polystyrene microspheres arranged on one side, which is conducive to large-scale rapid production. The polystyrene microspheres have good heat resistance, the chromium metal column has a large extinction coefficient and a high melting point, and the selected PET tape has the advantages of low refractive index, high transparency, good viscosity, and good heat resistance. The encapsulation layer 4 and the transfer layer 3 are both PET tapes, and the low-refractive PET tape is conducive to achieving the double-sided absorption performance of visible-near-infrared light. The visible-near-infrared light absorber provided in this embodiment has the properties of easy preparation, easy transfer, and good heat resistance.

[0048] In this embodiment, the diameter D of the polystyrene microspheres is 500 nm, and the period P of the polystyrene monolayer microsphere array is 520 nm. The polystyrene monolayer microsphere array prepared by gas-liquid interface colloidal self-assembly is non-densely distributed, and there are gaps between the polystyrene microspheres, which is conducive to using the gaps between the microspheres to form a non-dense high-loss metal layer 2 through magnetron DC sputtering, thereby improving the absorption rate of light.

[0049] In this embodiment, the height H of the high-loss metal column is 500 nm, and the side length L is 290 nm. The high-loss metal column is obtained by magnetron DC sputtering, forming periodically arranged hexagonal columnar chromium metal columns. The high-loss metal column is non-densely distributed, which is conducive to utilizing the gaps between the high-loss metal columns to improve the absorption rate of light.

[0050] Figure 1 This is a structural model diagram of the visible-near infrared light absorber. Figure 2 is a simulated absorption spectrum of a visible-near infrared absorber. Figure 1-2 In the visible-near-infrared light absorber provided in this embodiment, light in the visible-near-infrared range is incident in the direction of the chromium metal column (i.e., the front direction of the visible-near-infrared light absorber) and in the direction of the substrate 1 (i.e., the back direction of the visible-near-infrared light absorber) in sequence. In the 400-2500nm band, the simulated average absorptivity of the visible-near-infrared light absorber on the front and back sides are 89% and 91%, respectively.

[0051] The reflectance spectrum of the front side and the transmission spectrum of the back side of the visible-near infrared light absorber were measured by a spectrophotometer, and the absorption spectrum was obtained according to A=1-TR. Figure 3 is the absorption spectrum, see Figure 3 In the 400-2500nm band, the average absorption rates of the front and back sides of the visible-near-infrared light absorber reached 84% and 91% respectively, achieving efficient absorption of visible-near-infrared electromagnetic waves.

[0052] Example 3

[0053] The present embodiment provides a transferable visible-near-infrared light absorber, comprising an encapsulation layer 4, a substrate layer 1, a high-loss metal layer 2 and a transfer layer 3 arranged in sequence from bottom to top; the substrate layer 1 comprises a periodically arranged single-layer microsphere array, wherein the single-layer microsphere array is a silica microsphere; the substrate layer 1 is prepared by spin coating; the high-loss metal layer 2 comprises periodically arranged high-loss metal columns, and the high-loss metal columns comprise chromium metal columns; the high-loss metal layer 2 is obtained by magnetron DC sputtering of a high-loss metal on the substrate layer 1; the transfer layer 3 is adhered to a side of the high-loss metal layer 2 that is away from the substrate layer 1; the encapsulation layer 4 is adhered to a side of the substrate layer 1 that is away from the high-loss metal layer 2.

[0054] In this embodiment, the diameter D of the silica microspheres is 400 nm, and the period P is 405 nm.

[0055] In this embodiment, the height H of the chromium metal column is 300 nm, and the side length L is 220 nm.

[0056] Example 4

[0057] The present embodiment provides a transferable visible-near infrared light absorber, comprising an encapsulation layer 4, a substrate layer 1, a high-loss metal layer 2 and a transfer layer 3 arranged in sequence from bottom to top; the substrate layer 1 comprises a periodically arranged single-layer microsphere array, wherein the single-layer microsphere array is a silica microsphere; the substrate layer 1 is prepared by spin coating; the high-loss metal layer 2 comprises periodically arranged high-loss metal columns, and the high-loss metal columns comprise chromium metal columns; the high-loss metal layer 2 is obtained by magnetron DC sputtering of a high-loss metal on the substrate layer 1; the transfer layer 3 is a PET tape, which is adhered to the side of the high-loss metal layer 2 facing away from the substrate layer 1; the encapsulation layer 4 is a PET tape, which is adhered to the side of the substrate layer 1 facing away from the high-loss metal layer 2.

[0058] In this embodiment, the diameter D of the silica microspheres is 400 nm, and the period P is 420 nm.

[0059] In this embodiment, the height H of the chromium metal column is 300 nm, and the side length L is 220 nm.

[0060] Example 5

[0061] The present embodiment provides a transferable visible-near infrared light absorber, comprising an encapsulation layer 4, a substrate layer 1, a high-loss metal layer 2 and a transfer layer 3 arranged in sequence from bottom to top; the substrate layer 1 comprises a periodically arranged single-layer microsphere array, wherein the single-layer microsphere array is a polystyrene microsphere; the substrate layer 1 is prepared by gas-liquid interface colloid self-assembly; the high-loss metal layer 2 comprises periodically arranged high-loss metal columns, and the high-loss metal columns comprise chromium metal columns; the high-loss metal layer 2 is obtained by magnetron DC sputtering of a high-loss metal on the substrate layer 1; the transfer layer 3 is a PET tape, which is adhered to the side of the high-loss metal layer 2 facing away from the substrate layer 1; the encapsulation layer is a PET tape, which is adhered to the side of the substrate layer 1 facing away from the high-loss metal layer 2.

[0062] In this embodiment, the diameter D of the polystyrene microspheres is 600 nm, and the period P is 640 nm.

[0063] In this embodiment, the height H of the chromium metal column is 700 nm, and the side length L is 340 nm.

[0064] Example 6

[0065] The present embodiment provides a transferable visible-near infrared light absorber, comprising an encapsulation layer 4, a substrate layer 1, a high-loss metal layer 2 and a transfer layer 3 arranged in sequence from bottom to top; the substrate layer 1 comprises a periodically arranged single-layer microsphere array, wherein the single-layer microsphere array is a polystyrene microsphere; the substrate layer 1 is prepared by gas-liquid interface colloid self-assembly; the high-loss metal layer 2 comprises periodically arranged high-loss metal columns, and the high-loss metal columns comprise tungsten metal columns; the high-loss metal layer 2 is obtained by magnetron DC sputtering of a high-loss metal on the substrate layer 1; the transfer layer 3 is a PET tape, which is adhered to the side of the high-loss metal layer 2 facing away from the substrate layer 1; the encapsulation layer is a PET tape, which is adhered to the side of the substrate layer 1 facing away from the high-loss metal layer 2.

[0066] In this embodiment, the diameter D of the polystyrene microspheres is 600 nm, and the period P is 620 nm.

[0067] In this embodiment, the height H of the tungsten metal column is 700 nm, and the side length L is 360 nm.

[0068] Example 7

[0069] The present embodiment provides a transferable visible-near infrared light absorber, comprising an encapsulation layer, a substrate layer 1, a high-loss metal layer 2 and a transfer layer 3 arranged in sequence from bottom to top; the substrate layer 1 comprises a periodically arranged single-layer microsphere array, wherein the single-layer microsphere array is a polystyrene microsphere; the substrate layer 1 is prepared by gas-liquid interface colloid self-assembly; the high-loss metal layer 2 comprises periodically arranged high-loss metal columns, and the high-loss metal columns comprise chromium metal columns; the high-loss metal layer 2 is obtained by magnetron DC sputtering of a high-loss metal on the substrate layer 1; the transfer layer 3 is a PET tape, which is adhered to the side of the high-loss metal layer 2 facing away from the substrate layer 1; the encapsulation layer is a PET tape, which is adhered to the side of the substrate layer 1 facing away from the high-loss metal layer 2.

[0070] In this embodiment, the diameter D of the polystyrene microspheres is 500 nm, and the period PP of the single-layer microsphere array is 530 nm.

[0071] In this embodiment, the height H of the chromium metal column is 700 nm, and the side length L is 300 nm.

[0072] Example 8

[0073] The present embodiment provides a transferable visible-near infrared light absorber, comprising an encapsulation layer, a substrate layer 1, a high-loss metal layer 2 and a transfer layer 3 arranged in sequence from bottom to top; the substrate layer 1 comprises a periodically arranged single-layer microsphere array, wherein the single-layer microsphere array is a polystyrene microsphere; the substrate layer 1 is prepared by gas-liquid interface colloid self-assembly; the high-loss metal layer 2 comprises periodically arranged high-loss metal columns, and the high-loss metal columns comprise chromium metal columns; the high-loss metal layer 2 is obtained by magnetron DC sputtering of a high-loss metal on the substrate layer 1; the transfer layer 3 is a PET tape, which is adhered to the side of the high-loss metal layer 2 facing away from the substrate layer 1; the encapsulation layer is a PET tape, which is adhered to the side of the substrate layer 1 facing away from the high-loss metal layer 2.

[0074] In this embodiment, the diameter D of the polystyrene microspheres is 500 nm, and the period PP of the single-layer microsphere array is 510 nm.

[0075] In this embodiment, the height H of the chromium metal column is 700 nm, and the side length L is 280 nm.

[0076] Example 9

[0077] This embodiment provides a method for preparing the transferable visible-near infrared light absorber of embodiment 1. Figure 4 This is a schematic diagram of the experimental process of the visible-near infrared light absorber. Figure 5 is a flow chart of the preparation of visible-near infrared light absorbers, please refer to Figure 4-5 , the method for preparing a visible-near infrared light absorber comprises the following steps:

[0078] Step S1: using colloidal self-assembly to form a single-layer microsphere array with a period of P as the base layer 1. The specific operation is: preparing a single-layer microsphere array by air-liquid interface colloidal self-assembly or spin coating; transferring and drying the single-layer microsphere array to obtain the base layer 1.

[0079] Step S2: Prepare a high-loss metal layer 2 on the substrate layer 1 by magnetron sputtering. The specific operation is: put the single-layer microsphere array into a high-vacuum three-target magnetron sputtering coating machine and align it with the high-loss metal target, pump argon gas into the chamber, and sputter the high-loss metal target by direct current radio frequency to form high-loss metal columns with a period of P on the single-layer microsphere array.

[0080] Step S3: Paste the transfer layer 3 to the side of the high-loss metal layer 2 facing away from the base layer 1. Specifically, use PET tape as the transfer layer 3 and paste it to the side of the high-loss metal layer 2 facing away from the base layer 1 to achieve transfer.

[0081] Step S4: Paste the encapsulation layer 4 to the side of the substrate layer 1 away from the high-loss metal layer 2 to complete the encapsulation, and obtain a visible-near infrared light absorber that is easy to transfer and can absorb on both sides. Specifically, PET tape is used as the encapsulation layer 4 and pasted to the side of the substrate layer 1 away from the high-loss metal layer 2.

[0082] Before preparing the visible-near-infrared light absorber, a metamaterial absorber model diagram can be constructed by the finite-difference time-domain method (FDTD), and the simulated absorption spectrum of the metamaterial absorber can be calculated. By simulating and optimizing the parameters, the period P of the substrate layer 1, the diameter D of the microspheres, and the height H of the high-loss metal column can be finally determined.

[0083] Example 10

[0084] This embodiment provides a method for preparing the transferable visible-near infrared light absorber of embodiment 2, comprising the following steps:

[0085] Step S1: using the air-liquid interface colloidal self-assembly method to form a single-layer microsphere array with a period of P as the base layer 1.

[0086] Specifically, 400 mL of deionized water was placed in a glass container, and 20 μL of a 10 wt% SDS (sodium dodecyl sulfate) solution was dropped to reduce the liquid surface tension gradient; a glass plate was placed obliquely at the gas-liquid interface; a polystyrene microsphere solution with a mass fraction of 5 wt% and a single particle diameter D of 500 nm was selected, and the polystyrene microsphere solution and anhydrous ethanol were mixed in a volume ratio of 1:2 to obtain a mixed microsphere solution;

[0087] The mixed microsphere solution was slowly injected at the air-liquid interface on the glass plate by point injection, and the polystyrene microspheres self-assembled at the air-liquid interface to form a large-area monolayer ordered array with a period of P. A square silicon wafer with an area of ​​3 cm × 3 cm was used to transfer the polystyrene monolayer microsphere array and air-dried it naturally at room temperature.

[0088] Step S2: preparing a high-loss metal layer 2 on the substrate layer 1 by magnetron sputtering.

[0089] Specifically, the prepared polystyrene monolayer microsphere array was placed as a template in a high vacuum three-target magnetron sputtering coating machine and aligned with the metal chromium target. Argon was pumped into the chamber, and the sputtering mode was set to DC RF to sputter metal chromium on the polystyrene monolayer microsphere array. The vacuum degree of the chamber was 7×10 -2 Pa, argon gas flow rate is 20 cm 3 / min, the sputtering power is 50W, and the sputtering rate of metal chromium is about 8.3nm / min. Under this parameter, sputtering for 60min forms chromium metal columns with a height of 500nm on the polystyrene monolayer microsphere array. Figure 6 is a scanning electron microscope image of a chromium metal column, see Figure 6 , chromium metal columns are formed on the substrate layer 1 by magnetron DC sputtering, the periodicity of the chromium metal columns is well maintained, and the actual parameters are consistent with the simulation parameters.

[0090] When preparing the polystyrene microsphere solution, a solution of a certain concentration can be prepared according to the selected polystyrene microsphere diameter D to form a monolayer polystyrene monolayer microsphere array with a suitable period P. If the concentration of the polystyrene solution is too low, it will be difficult to form a periodically arranged microsphere array; if the concentration of the polystyrene solution is too high, the polystyrene microspheres may accumulate to form a multilayer disordered structure.

[0091] Step S3: Paste the transfer layer 3 to the side of the high-loss metal layer 2 facing away from the base layer 1. Specifically, use PET tape as the transfer layer 3 and paste it to the side of the high-loss metal layer 2 facing away from the base layer 1 to achieve transfer.

[0092] Step S4: Paste the encapsulation layer 4 to the side of the substrate layer 1 away from the high-loss metal layer 2. Specifically, use PET tape as the encapsulation layer 4 and paste it to the side of the substrate layer 1 away from the high-loss metal layer 2 to complete the encapsulation and obtain a visible-near infrared light absorber that is easy to transfer and can absorb on both sides.

[0093] Embodiment 11

[0094] This embodiment provides a method for preparing the transferable visible-near infrared light absorber of embodiment 3, comprising the following steps:

[0095] Step S1: forming a single-layer microsphere array with a period of P as the base layer 1 by spin coating.

[0096] Specifically, the silica microsphere solution is mixed and diluted with anhydrous ethanol in a certain proportion to obtain a mixed microsphere solution; the silicon substrate is placed on a coater, the coater is started to rotate at high speed, and the mixed microsphere solution is dripped onto the silicon substrate, and the solution is evenly spread on the silicon wafer under the action of centrifugal force; the coater is turned off, and a single-layer silica microsphere array is formed on the silicon substrate after the solvent evaporates.

[0097] When preparing colloidal crystals, the spin coating method can utilize the mechanism of colloid self-assembly to form an orderly arranged particle array. A mixed microsphere solution of a certain concentration can be selected according to the preset silica microsphere diameter, and a periodically arranged silica monolayer microsphere array with a certain spacing can be formed by spin coating.

[0098] Step S2: preparing a high-loss metal layer 2 on the substrate layer 1 by magnetron sputtering.

[0099] Specifically, the prepared silicon dioxide single-layer microsphere array is placed as a template in a high vacuum three-target magnetron sputtering coating machine and aligned with the metal chromium target, argon gas is pumped into the chamber, the sputtering mode is set to DC RF, and metal chromium is sputtered on the polystyrene single-layer microsphere array.

[0100] Step S3: Paste the transfer layer 3 to the side of the high-loss metal layer 2 facing away from the base layer 1. Specifically, use PET tape as the transfer layer 3 and paste it to the side of the high-loss metal layer 2 facing away from the base layer 1 to achieve transfer.

[0101] Step S4: Paste the encapsulation layer 4 to the side of the substrate layer 1 away from the high-loss metal layer 2. Specifically, use PET tape as the encapsulation layer 4 and paste it to the side of the substrate layer 1 away from the high-loss metal layer 2 to complete the encapsulation and obtain a visible-near infrared light absorber that is easy to transfer and can absorb on both sides.

[0102] The present invention is not limited to the above-mentioned embodiments. If various changes or modifications to the present invention do not depart from the spirit and scope of the present invention, and if these changes and modifications fall within the scope of the claims and equivalent technologies of the present invention, the present invention is also intended to include these changes and modifications.

Claims

1. A transferable visible-near infrared light absorber, characterized in that: It includes a packaging layer, a base layer, a high-loss metal layer and a transfer layer arranged in sequence from bottom to top; The base layer includes a periodically arranged single-layer microsphere array, wherein the single-layer microsphere array includes at least one of polystyrene microspheres and silica microspheres, wherein the single-layer microsphere array is prepared by a colloidal self-assembly method, and there are gaps between the microspheres of the single-layer microsphere array; The high-loss metal layer comprises periodically arranged high-loss metal columns, wherein the high-loss metal columns comprise at least one of chromium metal columns, titanium metal columns, tungsten metal columns, nickel metal columns, gold metal columns or silver metal columns; the high-loss metal layer is obtained by magnetron DC sputtering of high-loss metal on a substrate layer; The transfer layer is adhered to a side of the high-loss metal layer away from the base layer; The packaging layer is adhered to one side of the base layer.

2. The transferable visible-near infrared light absorber according to claim 1, characterized in that: The microspheres in the single-layer microsphere array are polystyrene microspheres, and the base layer is prepared by air-liquid interface colloid self-assembly.

3. The transferable visible-near infrared light absorber according to claim 1, characterized in that: The microspheres in the single-layer microsphere array are silicon dioxide microspheres, and the base layer is prepared by spin coating.

4. The transferable visible-near infrared light absorber according to any one of claims 1 to 3, characterized in that: In the single-layer microsphere array, the diameter of each microsphere is 400-600 nm.

5. The transferable visible-near infrared light absorber according to claim 4, characterized in that: The period of the single-layer microsphere array is 405-640 nm, wherein the period of the single-layer microsphere array is greater than the diameter of the microsphere.

6. The transferable visible-near infrared light absorber according to claim 4, characterized in that: The height of the high-loss metal column is 300-700 nm.

7. The transferable visible-near infrared light absorber according to claim 1, characterized in that: The transfer layer is a PET tape layer.

8. The transferable visible-near infrared light absorber according to claim 1, characterized in that: The packaging layer is a PET tape layer.

9. A method for preparing the transferable visible-near infrared light absorber according to any one of claims 1 to 8, characterized in that: The following steps are involved: A periodically arranged single-layer microsphere array is prepared by using a colloidal self-assembly method, so that there are gaps between the microspheres in the single-layer microsphere array to obtain a base layer; A high-loss metal layer is prepared on the substrate layer by magnetron DC sputtering; Adhere the transfer layer to the side of the high-loss metal layer facing away from the base layer; The encapsulation layer is adhered to the side of the substrate layer away from the high-loss metal layer to obtain a visible-near infrared light absorber.

10. The method for preparing a transferable visible-near infrared absorber according to claim 9, characterized in that: In the step of preparing the base layer by using the colloidal self-assembly method, a single-layer microsphere array is prepared by using the gas-liquid interface colloidal self-assembly method or the spin coating method, and the single-layer microsphere array is transferred and dried to obtain the base layer; In the step of preparing a high-loss metal layer on a substrate layer by magnetron sputtering, a single-layer microsphere array is placed in a high-vacuum three-target magnetron sputtering coating machine and aligned with a high-loss metal target, argon gas is pumped into the chamber, and the high-loss metal target is sputtered by direct current radio frequency to form periodic high-loss metal columns on the single-layer microsphere array.

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