Superstructure based on quasi-continuous domain bound state for realizing structural color and preparation method thereof

Abstract

The application provides an ultrastucture surface based on quasi-continuous domain bound state for realizing structural color and a preparation method, wherein titanium dioxide and silicon dioxide are used to form a nano antenna structure in the ultrastucture surface, titanium dioxide and silicon dioxide are used as the characteristics of all-dielectric materials, so that the ultrastucture surface can realize high-brightness structural color covering the full visible light region. By designing the nano antenna structure as an elliptical column structure, the symmetry of the column antenna structure is destroyed, so that the mode originally bound in the continuous domain leaks out to become an accessible quasi-continuous domain bound state, and a low half-width high reflection response is realized. By designing a nano antenna array matching layer, the disadvantage of increasing back reflection of the substrate is overcome, and high-saturation wide color gamut color display is realized. Therefore, the integration of structural color wide color gamut, high saturation, high brightness and low half-width high is realized, which is expected to bring a new way for the application of structural color in dynamic display, optical security and information storage.

Description

Technical Field

[0001] This invention relates to the field of structural color technology, and in particular to a metasurface that realizes structural color based on quasi-continuous domain bound states and its preparation method. Background Technology

[0002] Structural colors, also known as nanoscale or microscale structures, rely on the precise arrangement of these structures to produce vivid and iridescent colors that are impossible to achieve with pigments. The allure of structural colors lies in their ability to create dazzling optical effects by manipulating light itself. These nanostructures do not absorb specific wavelengths; instead, they intricately control the interference, diffraction, or scattering of light waves, resulting in vibrant colors that are often angle-dependent.

[0003] There are two common methods for achieving structural colors in existing technologies. One is to utilize the surface plasmon polariton (SPP) effect of metals. By constructing specific plasmon surface structures, the entire visible frequency range can be covered. Structural colors achieved through metallic metasurfaces have the advantage of ultra-high resolution, enabling applications such as microscopic image encryption, information storage, and nano-pattern art design. However, structural colors based on metallic plasmon polaritons are limited in achieving high brightness and high saturation due to inherent ohmic losses. The other method is all-dielectric metamaterials, which offer another way to generate highly saturated structural colors. To date, all-dielectric metasurfaces composed of high-refractive-index materials such as silicon (Si) and silicon nitride (Si3N4) generally exhibit higher brightness and more saturated colors than structural colors generated by surface plasmon polaritons. Dielectric materials, due to their inherent limitations, still cannot achieve structural colors that excel in all aspects. Silicon dielectric materials (including amorphous silicon and single-crystal silicon), with their high refractive index, can achieve structural colors with a wide color gamut, but at shorter wavelengths, due to inherent ohmic losses, they cannot achieve breakthroughs in high brightness. Meanwhile, it is difficult to achieve a sufficiently narrow half-width and height (FWHM>35nm) by using electric / magnetic dipoles for optical field modulation. Compared with silicon dielectric materials, titanium dioxide has negligible ohmic loss in the entire visible light region, which can achieve high brightness covering the entire visible light region. However, due to the low refractive index of titanium dioxide in the visible light region (n<2.4), it is difficult to achieve strong optical field modulation.

[0004] Given the urgent need for wide color gamut, high saturation, high brightness, and low half-width / height structural colors in information display technology, how to obtain micro-nano structures that simultaneously achieve wide color gamut, high brightness, high saturation, low half-width / height, and low fabrication difficulty, and further realize the demonstration application of micro-nano structures as important devices in high-resolution optical displays and sensing systems, thereby expanding and improving the application value of structural colors, is a huge challenge. Summary of the Invention

[0005] This invention provides a metasurface that realizes structural color based on quasi-continuous domain bound states, comprising: a dielectric substrate, a dielectric thin film, and a nanoantenna array composed of several elliptical cylindrical nanoantenna structures;

[0006] The dielectric substrate is located below the dielectric thin film;

[0007] The dielectric thin film is located between the dielectric substrate and the nanoantenna array;

[0008] The nanoantenna array is located above the dielectric film;

[0009] The nanoantenna structure includes a titanium dioxide layer and a matching layer; the titanium dioxide layer is disposed above the dielectric film, the matching layer is located above the titanium dioxide layer, and the matching layer is made of silicon dioxide.

[0010] Furthermore, the dielectric substrate is an ITO glass substrate.

[0011] Furthermore, the dielectric film is a silicon dioxide layer with a thickness between 80 nm and 100 nm.

[0012] Furthermore, the nanoantenna array includes: a plurality of periodically arranged photonic crystal units; wherein each photonic crystal unit includes four nanoantenna structures distributed in an X-shape, and the length of the photonic crystal unit is between 560 nm and 800 nm, and the width is between 360 nm and 480 nm.

[0013] Furthermore, the length of the major axis of the elliptical cylindrical nanoantenna structure is between 240 nm and 360 nm, the length of the minor axis is between 80 nm and 130 nm, the thickness of the titanium dioxide layer is 270 nm, and the thickness of the matching layer is 50 nm.

[0014] This invention provides a method for preparing metasurfaces with structural colors based on quasi-continuous domain bound states, used to prepare metasurfaces as described in any of the above embodiments.

[0015] The preparation method includes:

[0016] A dielectric thin film, a titanium dioxide layer, and a silicon dioxide layer are sequentially deposited on a dielectric substrate;

[0017] Photoresist is coated on the dielectric film, and the inverse structure pattern corresponding to the preset metasurface pattern is transferred onto the photoresist;

[0018] Chromium plating is performed using electron beam evaporation technology to form a mask;

[0019] By stripping the photoresist and removing the mask in the inverse structure pattern region, a metasurface structure composed of residual chromium from the mask is obtained;

[0020] Based on the metasurface structure composed of residual chromium from the mask, the titanium dioxide layer and the silicon dioxide layer are etched into a nanoantenna array composed of several elliptical cylindrical nanoantenna structures to obtain a metasurface for realizing structural color.

[0021] Furthermore, the sequential deposition of a dielectric thin film, a titanium dioxide layer, and a silicon dioxide layer on the dielectric substrate includes:

[0022] A dielectric thin film with a thickness between 80 nm and 100 nm, a titanium dioxide layer with a thickness of 270 nm, and a silicon dioxide layer with a thickness of 50 nm are sequentially deposited on the dielectric substrate.

[0023] Furthermore, the step of coating photoresist on the dielectric film and transferring the inverse structure pattern corresponding to the preset metasurface pattern onto the photoresist includes:

[0024] Photoresist is coated onto the dielectric film by spin coating.

[0025] After the photoresist is dried, it is exposed using an electron beam lithography machine to transfer the preset metasurface pattern onto the photoresist;

[0026] The photoresist is developed using a developer to generate an inverse structure pattern corresponding to the metasurface pattern.

[0027] Furthermore, chromium plating is performed using electron beam evaporation technology to form a mask, including:

[0028] During chromium plating, the vacuum level inside the electron beam evaporation machine is maintained at 5E-7 Torr, and the chromium plating speed of the electron beam evaporation machine is maintained at... Chromium plating was stopped when the mask thickness was detected to reach 27nm.

[0029] Furthermore, the step of etching the titanium dioxide layer and the silicon dioxide layer into a nanoantenna array composed of several elliptical cylindrical nanoantenna structures based on the metasurface structure composed of chromium residue from the mask includes:

[0030] Based on the metasurface structure composed of chromium residue from the mask, the titanium dioxide layer and the silicon dioxide layer are etched to obtain several elliptical cylindrical nanoantenna structures with chromium on their surfaces.

[0031] The chromium on the surface of the nanoantenna structure is removed using chemical reagents to obtain a nanoantenna structure composed of titanium dioxide and silicon dioxide, and a nanoantenna array composed of several nanoantenna structures.

[0032] The following benefits can be obtained by implementing the present invention:

[0033] This invention provides a metasurface and its fabrication method for achieving structural color based on quasi-continuous domain bound states. Since the nanoantenna structure in the metasurface is entirely composed of titanium dioxide and silicon dioxide, it easily meets the requirements of scalability and long-term stability. Furthermore, both titanium dioxide and silicon dioxide are all dielectric materials, and the nanoantenna structure based on these materials can achieve high-brightness structural color covering the entire visible light spectrum. By designing the nanoantenna structure as an elliptical cylindrical structure, the symmetry of the cylindrical antenna structure is broken, allowing the modes (BIC) originally bound in the continuous domain to leak out and become accessible quasi-continuous domain bound states (quasi-BIC), achieving a low half-width and height (FWHM) reflection response. Further, by designing a matching layer for the nanoantenna array, the drawback of increased back reflection on the substrate is overcome, achieving high-saturation, wide-gamut color display. Therefore, this invention achieves a breakthrough in the integrated application of structural color with wide color gamut, high saturation, high brightness, and low FWHM, a development that is expected to bring new avenues for the commercial application of structural color in dynamic displays, optical security, and information storage. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of a metasurface that realizes structural color based on quasi-continuous domain bound states, according to an embodiment of the present invention.

[0035] Figure 2 This is a schematic diagram of spectral data of a metasurface composed of different nanoantenna structures provided in an embodiment of the present invention.

[0036] Figure 3 This is a schematic diagram of the electric field spatial distribution of two quasi-continuous domain bound state modes of a metasurface that realizes structural color based on quasi-continuous domain bound states, according to an embodiment of the present invention.

[0037] Figure 4 This is a schematic diagram of the structure of a photonic crystal unit cell in a nano-antenna array provided in an embodiment of the present invention.

[0038] Figure 5 This is a schematic diagram of the spectral data of a metasurface composed of nanoantenna structures based on different rotation angles, provided in an embodiment of the present invention.

[0039] Figure 6 This is a schematic diagram of the electric field spatial distribution of a metasurface that realizes structural color based on quasi-continuous domain bound states according to an embodiment of the present invention, based on the rotation angle of different incident polarized light.

[0040] Figure 7This is a color gamut area performance diagram of a metasurface that realizes structural color based on quasi-continuous domain bound states, provided by an embodiment of the present invention.

[0041] Figure 8 This invention provides an embodiment of various structural colors achieved by a metasurface based on quasi-continuous domain bound states.

[0042] Figure 9 This is an electron microscope image of a metasurface that realizes structural color based on quasi-continuous domain bound states, provided by an embodiment of the present invention. Detailed Implementation

[0043] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] See Figure 1 This is a schematic diagram of a metasurface that realizes structural color based on quasi-continuous domain bound states, provided by an embodiment of the present invention. It includes: a dielectric substrate, a dielectric thin film, and a nanoantenna array composed of several elliptical cylindrical nanoantenna structures.

[0045] The dielectric substrate is located below the dielectric thin film;

[0046] The dielectric thin film is located between the dielectric substrate and the nanoantenna array;

[0047] The nanoantenna array is located above the dielectric film;

[0048] The nanoantenna structure includes a titanium dioxide layer and a matching layer; the titanium dioxide layer is disposed above the dielectric film, the matching layer is located above the titanium dioxide layer, and the matching layer is made of silicon dioxide.

[0049] In one embodiment of the present invention, the nanoantenna structure composed of titanium dioxide and silicon dioxide is used to reflect light in a specific wavelength band. It should be noted that using titanium dioxide, a material with stable properties, to fabricate the nanoantenna structure leverages the advantages of titanium dioxide as a commonly used dielectric material and the mature micro / nano fabrication technology, meeting the requirements of mass production and long-term durability. Furthermore, a refractive index matching layer made of silicon dioxide is set on the top layer of the nanoantenna structure. The purpose is to use silicon dioxide to suppress substrate reflection, which can greatly increase the saturation of the structural color. Figure 2As shown, Figure a presents the spectral data of a metasurface composed solely of a nanoantenna structure made of a single layer of titanium dioxide, and Figure b presents the spectral data of a metasurface composed of nanoantenna structures made of both titanium dioxide and silicon dioxide. Further, as... Figure 3 As shown Figure 2 The spatial distribution of the electric field in the two quasi-continuous bound state modes in the fourth row of Figure b is clearly a BIC mode. Therefore, it is evident that Figure b exhibits superior structural color compared to Figure a.

[0050] Preferably, the dielectric substrate is an ITO glass substrate.

[0051] In one embodiment of the present invention, the dielectric substrate is composed of silicate glass and 13nm indium tin oxide on its surface.

[0052] Preferably, the dielectric film is a silicon dioxide layer with a thickness between 80 nm and 100 nm.

[0053] Preferably, the nanoantenna array comprises: a plurality of periodically arranged photonic crystal units; wherein each photonic crystal unit includes four nanoantenna structures distributed in an X-shape, and the length of the photonic crystal unit is between 560 nm and 800 nm, and the width is between 360 nm and 480 nm.

[0054] In one embodiment of the present invention, such as Figure 4 The diagram shows a schematic of a photonic crystal unit cell. It should be noted that the rotation angle of the nanoantenna structure, i.e., the rotation angle (eta) of the major axis of the elliptical cylinder relative to the z-axis, can significantly affect the quality factor (Q factor) of the mode. Therefore, by designing the rotation angle of the nanoantenna structure within the photonic crystal unit cell, the two quasi-continuous bound state modes of the structure can appear with appropriate quality factors and response wavelengths, resulting in a more ideal color spectrum. Furthermore, thanks to the high quality factor of the quasi-continuous bound state, the half-width and height of the structural color can be maintained at 15–20 nm.

[0055] It should be further explained that, experimental calculations show that, as Figure 5 As shown, good structural color can be obtained within a fairly large range of rotation angles of the nanoantenna structure, namely 20° to 50°. In this embodiment, 26° was selected as the optimal angle.

[0056] Preferably, the length of the major axis of the elliptical cylindrical nanoantenna structure is between 240 nm and 360 nm, the length of the minor axis is between 80 nm and 130 nm, the thickness of the titanium dioxide layer is 270 nm, and the thickness of the matching layer is 50 nm.

[0057] In one embodiment of the present invention, the nanoantenna structure is designed as an elliptical cylindrical structure. The purpose of this design is to introduce perturbation by ellipticizing the structure, thereby disrupting the symmetry of the cylindrical antenna structure and allowing the modes (BICs) originally bound in the continuous domain to leak out and become accessible quasi-continuous bound states (quasi-BICs).

[0058] Furthermore, since the elliptical cylindrical structure is not symmetric about y = x, the quasi-BIC mode responses of linearly polarized light in the y and x directions are different, such as... Figure 6 As shown, by analyzing Figure 2 Scanning the rotation angle of the incident polarized light in the fourth row of Figure b allows for dynamic control of the structural color by adjusting the rotation angle of the incident polarized light. Therefore, it is also possible to further disrupt the symmetry of the nanoantenna structure and enhance the mode response between arrays by controlling the rotation angle.

[0059] Furthermore, calculations using the commercial software Ansys Lumerical FDTD solution showed that the metasurface composed of the aforementioned nanoantenna structure could be obtained in the CIE 1931 chromaticity diagram as follows. Figure 7 As shown in the color gamut distribution, it is easy to see that the metasurface can achieve 1.577 times the Adobe RGB color gamut and 1.125 times the UHDTV (Rec.2020) color gamut. Finally, as Figure 8 As shown, the various structural colors achieved by the metasurface are displayed through different colors. When the sample is illuminated by linearly polarized white light under a microscope, a uniform and distinct color image from blue, green to red can be clearly seen in the figure.

[0060] This invention provides a metasurface for achieving structural color based on quasi-continuous domain bound states. Since the nanoantenna structure in this metasurface is entirely composed of titanium dioxide and silicon dioxide, it easily meets the requirements of scalability and long-term stability. Furthermore, both titanium dioxide and silicon dioxide are all dielectric materials, and the nanoantenna structure based on these materials can achieve high-brightness structural color covering the entire visible light spectrum. By designing the nanoantenna structure as an elliptical cylindrical structure, the symmetry of the cylindrical antenna structure is broken, allowing the modes (BICs) originally bound in the continuous domain to leak out and become accessible quasi-continuous domain bound states (quasi-BICs), achieving a low half-width and height (HWHM) reflection response. Further, by designing a matching layer for the nanoantenna array, the drawback of increased back reflection from the substrate is overcome, achieving high-saturation, wide-gamut color display. Therefore, this invention achieves a breakthrough in the integrated application of structural color with wide color gamut, high saturation, high brightness, and low HWHM, a development that is expected to bring new avenues for the commercial application of structural color in dynamic displays, optical security, and information storage.

[0061] Another embodiment of the present invention provides a method for preparing a metasurface with structural color based on quasi-continuous domain bound states, used to prepare the metasurface as described in any of the above embodiments of the invention.

[0062] The preparation method includes:

[0063] S1. Sequentially deposit a dielectric thin film, a titanium dioxide layer, and a silicon dioxide layer on a dielectric substrate;

[0064] Preferably, a dielectric thin film with a thickness between 80 nm and 100 nm, a titanium dioxide layer with a thickness of 270 nm, and a silicon dioxide layer with a thickness of 50 nm are sequentially deposited on the dielectric substrate.

[0065] In a preferred embodiment of the present invention, three dielectric layers of predetermined thickness—namely, a dielectric thin film, a titanium dioxide layer, and a silicon dioxide layer—are deposited on a 13nm indium tin oxide substrate. The thicknesses of the titanium dioxide layer and the silicon dioxide layer are consistent with the thicknesses of the titanium dioxide layer and the silicon dioxide layer in the final fabricated nanoantenna structure.

[0066] S2. Coat the dielectric film with photoresist and transfer the inverse structure pattern corresponding to the preset metasurface pattern onto the photoresist;

[0067] Preferably, the step of coating photoresist on the dielectric film and transferring the inverse structure pattern corresponding to the preset metasurface pattern onto the photoresist includes:

[0068] S21. Photoresist is coated onto the dielectric film by spin coating.

[0069] In a preferred embodiment of the present invention, PMMA (polymethyl methacrylate) photoresist is spin-coated onto a dielectric film. Since the spin speed and holding time determine the photoresist thickness, in this embodiment, the spin-coating speed is maintained at 4000 r / s and held for 60 s. After spin-coating, the photoresist is baked at 180°C for 45 minutes.

[0070] S22. After the photoresist is dried, it is exposed using an electron beam lithography machine to transfer the preset metasurface pattern onto the photoresist.

[0071] S23. Develop the photoresist using a developer to generate an inverse structure pattern corresponding to the metasurface pattern.

[0072] In a preferred embodiment of the present invention, a PMMA-specific developer is used for development, and the development time is 30 seconds.

[0073] S3. Chromium plating is performed using electron beam evaporation technology to form a mask;

[0074] Preferably, during chromium plating, the vacuum level inside the cavity of the electron beam evaporation machine is maintained at 5E-7 Torr, and the chromium plating speed of the electron beam evaporation machine is maintained at... Chromium plating was stopped when the mask thickness was detected to reach 27nm.

[0075] In a preferred embodiment of the present invention, in order to obtain a mask with uniform particles, the deposition rate cannot be too fast. Therefore, it is necessary to control the chromium deposition rate of the electron beam evaporation machine to be maintained at a certain level.

[0076] S4. By stripping the photoresist, the mask in the reverse structure pattern area is removed to obtain a metasurface structure composed of chromium residue from the mask.

[0077] In a preferred embodiment of the present invention, a stripping solution specifically for PMMA is used to strip the photoresist in the reverse structure pattern region to obtain a metasurface structure composed of residual chromium from the mask.

[0078] S5. Based on the metasurface structure composed of residual chromium from the mask, the titanium dioxide layer and the silicon dioxide layer are etched into a nanoantenna array composed of several elliptical cylindrical nanoantenna structures to obtain a metasurface for realizing structural color.

[0079] In a preferred embodiment of the present invention, such as Figure 9 The image shown is an electron microscope image of the metasurface prepared by the method described above. It can be seen that the nanoantenna structure of the prepared metasurface has smooth edges and vertical sidewalls that are close to 90°.

[0080] Preferably, the step of etching the titanium dioxide layer and the silicon dioxide layer into a nanoantenna array composed of a plurality of elliptical cylindrical nanoantenna structures based on the metasurface structure composed of chromium residue from the mask includes:

[0081] Based on the metasurface structure composed of chromium residue from the mask, the titanium dioxide layer and the silicon dioxide layer are etched to obtain several elliptical cylindrical nanoantenna structures with chromium on their surfaces.

[0082] In a preferred embodiment of the present invention, the titanium dioxide layer and the silicon dioxide layer are etched using reactive ion beam etching.

[0083] The chromium on the surface of the nanoantenna structure is removed using chemical reagents to obtain a nanoantenna structure composed of titanium dioxide and silicon dioxide, and a nanoantenna array composed of several nanoantenna structures.

[0084] In a preferred embodiment of the present invention, the chromium remaining on the surface of the nanoantenna structure is fully removed by immersing the nanoantenna array in a chromium removal solution for ten minutes.

[0085] This invention provides a method for preparing metasurfaces with structural colors based on quasi-continuous domain bound states. The preparation process is relatively simple. Although it requires etching of two layers of structure, it can be completed in a single etching process. At the same time, the micro-nano preparation process of titanium dioxide is mature, which enables the preparation of high-quality colored patterns with low cost and fast processing speed.

[0086] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A metasurface for structural color based on quasi-continuous band gap states, characterized in that, include: Dielectric substrate, dielectric thin film, and nanoantenna array composed of several elliptical cylindrical nanoantenna structures; The dielectric substrate is located below the dielectric thin film; The dielectric film is located between the dielectric substrate and the nanoantenna array, and the dielectric film is a silicon dioxide layer with a thickness between 80 nm and 100 nm. The nanoantenna array is located above the dielectric film; the nanoantenna array includes: a plurality of periodically arranged photonic crystal units; wherein each photonic crystal unit includes four nanoantenna structures distributed in an X-shape, and the length of the photonic crystal unit is between 560 nm and 800 nm, and the width is between 360 nm and 480 nm. The nanoantenna structure includes: a titanium dioxide layer and a matching layer; the titanium dioxide layer is disposed above the dielectric film, the matching layer is located above the titanium dioxide layer, and the matching layer is made of silicon dioxide. The length of the major axis of the elliptical cylindrical nanoantenna structure is between 240 nm and 360 nm, the length of the minor axis is between 80 nm and 130 nm, the thickness of the titanium dioxide layer is 270 nm, and the thickness of the matching layer is 50 nm.

2. The metasurface for realizing structural color based on quasi-continuous domain bound states as described in claim 1, characterized in that, The dielectric substrate is an ITO glass substrate.

3. A method for preparing a metasurface with structural color based on quasi-continuous domain bound states, characterized in that, Used to prepare the metasurface as described in any one of claims 1-2, The preparation method includes: A dielectric thin film, a titanium dioxide layer, and a silicon dioxide layer are sequentially deposited on a dielectric substrate; Photoresist is coated on the dielectric film, and the inverse structure pattern corresponding to the preset metasurface pattern is transferred onto the photoresist; Chromium plating is performed using electron beam evaporation technology to form a mask; By stripping the photoresist and removing the mask in the inverse structure pattern region, a metasurface structure composed of residual chromium from the mask is obtained; Based on the metasurface structure composed of residual chromium from the mask, the titanium dioxide layer and the silicon dioxide layer are etched into a nanoantenna array composed of several elliptical cylindrical nanoantenna structures to obtain a metasurface for realizing structural color.

4. The method for preparing a metasurface with structural color based on quasi-continuous domain bound states as described in claim 3, characterized in that, The process of sequentially depositing a dielectric thin film, a titanium dioxide layer, and a silicon dioxide layer on a dielectric substrate includes: A dielectric thin film with a thickness between 80 nm and 100 nm, a titanium dioxide layer with a thickness of 270 nm, and a silicon dioxide layer with a thickness of 50 nm are sequentially deposited on the dielectric substrate.

5. The method for preparing a metasurface with structural color based on quasi-continuous domain bound states as described in claim 4, characterized in that, The step of coating photoresist on the dielectric film and transferring the inverse structure pattern corresponding to the preset metasurface pattern onto the photoresist includes: Photoresist is coated onto the dielectric film by spin coating. After the photoresist is dried, it is exposed using an electron beam lithography machine to transfer the preset metasurface pattern onto the photoresist; The photoresist is developed using a developer to generate an inverse structure pattern corresponding to the metasurface pattern.

6. The method for preparing a metasurface with structural color based on quasi-continuous domain bound states as described in claim 5, characterized in that, Chromium plating is performed using electron beam evaporation technology to form a mask, including: During chromium plating, the vacuum level inside the cavity of the electron beam evaporation machine is maintained at 5E-7 Torr, and the chromium plating speed of the electron beam evaporation machine is maintained at 0.45 Å / s. Chromium plating is stopped when the mask thickness is detected to reach 27 nm.

7. The method for preparing a metasurface with structural color based on quasi-continuous domain bound states as described in claim 6, characterized in that, The step of etching the titanium dioxide layer and the silicon dioxide layer into a nanoantenna array composed of several elliptical cylindrical nanoantenna structures based on the metasurface structure composed of chromium residue from the mask includes: Based on the metasurface structure composed of chromium residue from the mask, the titanium dioxide layer and the silicon dioxide layer are etched to obtain several elliptical cylindrical nanoantenna structures with chromium on their surfaces. The chromium on the surface of the nanoantenna structure is removed using chemical reagents to obtain a nanoantenna structure composed of titanium dioxide and silicon dioxide, and a nanoantenna array composed of several nanoantenna structures.

Images