Color controller composed of prismatic metal dielectric units and preparation method thereof

Abstract

This invention belongs to the field of color display and optical materials, specifically disclosing a color controller composed of prismatic metal dielectric units and its fabrication method. The color controller includes a bottom silver film and multiple periodically arranged prismatic structural units on the bottom silver film; each prismatic structural unit includes a top aluminum film and an intermediate dielectric layer, the intermediate dielectric layer being a diamond layer. This invention cleverly optimizes the intrinsic properties of the material through the periodically arranged prismatic structural units, thereby achieving highly efficient selective absorption of visible light. It possesses advantages such as controllability, stability, and reliability, and is applicable to multiple fields such as electronic devices, optical sensors, and smart displays.

Description

Technical Field

[0001] This invention belongs to the field of color display and optical materials, specifically relating to a color controller composed of prism-shaped metal dielectric units and its preparation method. Background Technology

[0002] Color plays a crucial role in daily life. Traditional dyes and pigments primarily produce color by absorbing and reflecting light, but these colors appear dull, have poor resolution, and limited color gamut. Furthermore, these substances suffer from poor chemical stability, easily fading under high temperatures or strong ultraviolet radiation. In stark contrast, structural colors possess numerous advantages, including rich and diverse colors, high saturation, and strong stability, achieving a wider color gamut coverage and thus displaying richer, more vibrant, and dazzling color effects. Structural colors achieve the reflection of specific wavelengths of light by adjusting the interference and scattering of light. Because the creation of structural colors stems from the interaction of light waves, rather than a chemical absorption process, this characteristic makes their production process more environmentally friendly.

[0003] Traditional color controllers are typically limited to achieving color changes by adjusting geometric features such as shape, spacing, or periodicity. This approach is not only simplistic but also lacks adjustability in the displayed colors. More importantly, these controllers maintain color consistency under different polarized light illumination, limiting their application range. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention aims to provide a color controller composed of prism-shaped metal dielectric units. By using periodically arranged prism structural units, the intrinsic properties of the material are cleverly optimized, thereby achieving efficient selective absorption of visible light. It has advantages such as controllability, stability, and reliability, and is applicable to multiple fields such as electronic devices, optical sensors, and smart displays.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A color controller composed of prism-shaped metal dielectric units includes a bottom silver film and multiple prism structure units periodically arranged on the bottom silver film; the prism structure unit includes a top aluminum film and an intermediate dielectric layer, wherein the intermediate dielectric layer is a diamond layer.

[0007] Preferably, the prism structure unit is a quadrilateral prism.

[0008] Preferably, the prism structure unit and the parallel cross section of the underlying silver film are designed in a rhombus shape.

[0009] Preferably, the arrangement period of the prism structure units on the bottom silver film is 300nm.

[0010] Preferably, the thickness of the underlying silver film is 300 nm.

[0011] Preferably, the thickness of the top aluminum film is 50 nm, and the thickness of the diamond layer is 16 nm.

[0012] Preferably, the major axis and minor axis of the prism structure unit are 50 nm and 40 nm, respectively.

[0013] Preferably, the refractive index of the top aluminum film is 1.372 in the visible light range, the refractive index of the middle diamond layer is 2.42, and the refractive index of the bottom silver film is 0.288.

[0014] Accordingly, the present invention also proposes a method for fabricating a color controller based on the above-mentioned prism-shaped metal dielectric units, comprising the following steps:

[0015] 1) A silicon wafer of a certain thickness is used as a substrate, and a silver layer is deposited on the substrate using an electron beam evaporator to reflect sunlight;

[0016] 2) Diamond and aluminum are deposited layer by layer using plasma-enhanced chemical vapor deposition to form an intermediate diamond layer and a top aluminum film;

[0017] 3) The surface of the top aluminum film is coated with photoresist and exposed using a photolithography device through a diamond-shaped mask;

[0018] 4) Clean the photoresist after the reaction and use plasma etching to etch the desired prism pattern on the aluminum surface;

[0019] 5) The reflectance of the prepared metafabric sample in the ultraviolet, visible and near-infrared bands was measured by a UV-Vis-NIR spectrophotometer equipped with a diffuse integrating sphere to perform spectral detection of the color controller.

[0020] The beneficial effects of this invention are as follows:

[0021] This invention provides a color regulator composed of prism-shaped metal dielectric structure units and an underlying metal film, offering an effective method for achieving sustainable and controllable color display. This color regulator fully utilizes the principles and advantages of structural colors, possessing excellent controllability and the ability to adjust color display according to different needs. It not only brings new breakthroughs and development opportunities to color display technology but also provides higher-quality, more environmentally friendly, and more diverse color solutions for many related fields, such as electronic devices, optical sensors, and smart displays. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the color controller of the present invention;

[0023] Figure 2 The color modulator of this invention has a reflectance spectrum in the visible light range under x-polarization and y-polarization modes.

[0024] Figure 3 The reflection spectra in the visible light range under x-polarization and y-polarization modes for different materials in the intermediate dielectric layer of this invention;

[0025] Figure 4 This invention illustrates the effect of different dielectric layer thicknesses on the reflection spectrum under x-polarization (a) and y-polarization (c) conditions, and the corresponding CIE coordinate diagrams.

[0026] Figure 5 The following are the reflection spectra of the color controller of the present invention at different polarization angles;

[0027] Figure 6 This is a diagram showing the reflection spectrum and corresponding RGB values ​​of the color controller of the present invention under different ratios of the major and minor axes of the prisms during x-polarization.

[0028] Explanation of the attached drawing numbers:

[0029] Figure 1 (a) is the overall structural view of the color controller, (b) is the top view, and (c) is the side view;

[0030] Figure 4 In the middle, (b) corresponds to (a), and (d) corresponds to (c);

[0031] Figure 5 (b) shows the corresponding color points of the spectrum on the CIE diagram, and (c) shows the RGB values ​​corresponding to the color when the thickness of the intermediate dielectric layer is 16 nm. Detailed Implementation

[0032] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are for illustrative purposes only and are not intended to limit the scope of the invention.

[0033] like Figure 1-5 As shown, to broaden the control methods of color displays, this invention introduces a control mechanism that is completely different from traditional color controllers. Specifically, it proposes a color controller composed of prism-shaped metal dielectric units, including multiple periodically arranged prism structure units on a bottom silver film. Each prism structure unit includes a top aluminum film and an intermediate dielectric layer, the intermediate dielectric layer being a diamond layer. Utilizing the electromagnetic resonance characteristics of this three-layer structure, reflection of specific wavelengths within the visible light range can be achieved. This color controller can not only change color by adjusting structural parameters, but more importantly, it can also change color by altering the polarization angle of light.

[0034] The advantage of this color regulator lies in its ability to flexibly control color through the polarization state of light, without relying on changes in physical structure. This improves the flexibility and accuracy of color control, and its higher stability and durability are also due to its independence from changes in physical dimensions. Furthermore, because the intermediate dielectric layer of this regulator is made of inorganic diamond, it not only has a longer service life but also maintains stable performance under high temperatures and ultraviolet radiation.

[0035] This invention defines the upper surface of the bottom silver film as the xy plane, and the direction perpendicular to the upper surface as the z-direction. The prism structure unit is a quadrilateral prism with a rhomboid cross-section in the xy plane. The generation and control of color mainly depend on the interference and resonance effects of light. The asymmetric design of the prism structure unit in this invention provides a basis for the control of color display. In specific implementation, the different thicknesses, polarization angles, and major-minor axis ratios of the intermediate dielectric layer of different prism structure units can effectively change the optical path, affect the interference effect, and thus achieve the display of specific colors. The greater the thickness of the intermediate dielectric layer, the more likely the resonance peak will show a blue shift during the color control process; an increase in the polarization angle and the major-minor axis ratio will cause a red shift in the resonance peak.

[0036] In this embodiment, the thickness of the bottom silver film is d1 = 300 nm. The thickness of the top aluminum film is d3 = 50 nm, and the thickness of the diamond layer is d2 = 16 nm. The major and minor axes of the prism structure unit are a = 50 nm and b = 40 nm, respectively.

[0037] The refractive index of the top aluminum film in the visible light range is 1.372, the refractive index of the middle diamond layer is 2.42, and the refractive index of the bottom silver film is 0.288. The difference in refractive index causes light to undergo different degrees of refraction, reflection and interference effects at the interfaces of each layer.

[0038] The prism structure units are arranged in a period of 300 nm in the xy plane. The electromagnetic interaction between these periodically designed prism structure units is crucial for the color controller to function.

[0039] Accordingly, based on the color controller composed of the aforementioned prism-shaped metal dielectric units, this invention also proposes a method for fabricating the color controller, comprising the following steps:

[0040] 1) A silicon wafer of appropriate thickness is used as a substrate, and a silver layer is deposited on the substrate using an electron beam evaporator to reflect sunlight;

[0041] 2) Diamond and aluminum are deposited layer by layer using plasma-enhanced chemical vapor deposition to form an intermediate diamond layer and a top aluminum film;

[0042] 3) The surface of the top aluminum film is coated with photoresist and exposed using a photolithography device through a diamond-shaped mask;

[0043] 4) Clean the photoresist after the reaction and use plasma etching to etch the desired prism pattern on the aluminum surface;

[0044] 5) The reflectance of the prepared metafabric sample (i.e., the color controller sample of this application) in the ultraviolet, visible and near-infrared bands (UV-Vis-NIR) is measured by a UV-Vis-NIR spectrophotometer equipped with a diffuse integrating sphere (wavelength 0.25-2.5μm, model Carry5000, Agilent) to perform spectral detection of the color controller.

[0045] Simulation Experiment

[0046] This invention employs the three-dimensional finite element multiphysics simulation software COMSOL Multiphysics for simulation. During the simulation, only a single prism structure element needs to be calculated, and an infinitely large array structure is simulated by setting periodic boundaries in the planar direction. Similarly, the upper surface of the underlying silver film is defined as the xy plane, and the direction perpendicular to the upper surface is defined as the z-direction. A plane electromagnetic wave is incident along the z-axis, and the electric field incident direction is along the y-axis. Periodic boundary conditions are applied in the x and y-axis directions, and a perfectly matched layer is used in the z-direction to eliminate non-physical reflections at the boundary. The mesh is set to fine, and then frequency domain scanning is performed to calculate the absorption and reflection results, thereby obtaining the corresponding absorption and reflection spectra.

[0047] To investigate the effects of the thickness of the intermediate dielectric layer, polarization angle, and major-minor axis ratio of the aluminum / diamond prism on the color regulator of this invention, simulation experiments were conducted. Except for the variable parameters, the thickness of the intermediate dielectric layer, polarization angle, and major-minor axis ratio of the aluminum / diamond prism were changed sequentially while keeping other parameters constant. The simulation results are as follows:

[0048] Figure 2 The reflection spectra of the color modulator of the present invention in the visible light band under x-polarization and y-polarization modes were demonstrated using the parameters set in the above embodiments. The reflection spectra show that the resonance peaks in the x-polarization and y-polarization modes are located at 558 nm and 615 nm, respectively, corresponding to purple and green colors. This significant feature indicates that the color modulator composed of the prism-shaped metallic dielectric structure unit and the underlying metallic film possesses color display functionality and polarization control characteristics.

[0049] Figure 3 The effects of different intermediate dielectric layer materials on the reflectance spectrum in the visible light range are described. Experiments were conducted using the parameters set in the above embodiments, with variations in the intermediate dielectric layer material.

[0050] in Figure 3(a) shows the visible light reflectance spectra of different intermediate dielectric layer materials under x-polarized light. From Figure 3 As clearly observed in (a), the change in reflectance spectrum is significant with the alteration of the intermediate medium material. Under x-polarized light, the corresponding reflectance spectral peak positions for diamond, silicon dioxide, silicon nitride, and hafnium dioxide are 558 nm, 496 nm, 567 nm, and 505 nm, respectively; under y-polarized light, the corresponding reflectance spectral peak positions are 615 nm, 551 nm, 623 nm, and 558 nm, respectively. This indicates that diamond has a relatively wide spectral tuning range of 57 nm compared to other intermediate materials, allowing it to display richer and more diverse colors.

[0051] Figure 4 The effect of varying the thickness of the intermediate dielectric layer on the reflectance spectrum in the visible light range is described. Experiments were conducted using the parameters set in the above embodiment, with variations in the thickness of the intermediate dielectric layer.

[0052] in Figure 4 (a) and Figure 4 (b) shows the visible light reflectance spectra corresponding to different intermediate medium layer thicknesses d2 under x-polarized and y-polarized light conditions. Figure 4 (a) It can be clearly seen that as the thickness of the intermediate medium layer increases from 12nm to 20nm in increments of 2nm, i.e., the thickness of the diamond layer is 12nm, 14nm, 16nm, 18nm, and 20nm, the corresponding reflection spectral peak positions are 610nm, 580nm, 558nm, 538nm, and 520nm, respectively. Therefore, the reflection spectrum of the x-polarized light exhibits a blue shift, and the color gradually changes from light green to dark purple.

[0053] Corresponding CIE coordinates Figure 4 (c) The color change trend can be observed more clearly; the points corresponding to different thicknesses on the CIE coordinate graph show a counter-clockwise change from A to E. Similarly, from Figure 4 (b) It can be clearly seen that, with other parameters remaining constant, as the thickness of the intermediate medium layer increases from 12 nm to 20 nm, the corresponding reflection spectral peak positions are 675 nm, 641 nm, 615 nm, 594 nm, and 576 nm, respectively. It can be observed that the reflection spectrum of y-polarized light exhibits a blue shift. The color also changes accordingly from yellowish-green to dark blue.

[0054] Corresponding CIE coordinates Figure 4(d) The color change trend can be observed more clearly, with the point corresponding to the color change trend showing a counterclockwise change from A to E. These observations strongly suggest that changing the thickness of the dielectric layer can achieve a blue shift in the reflection spectrum, thereby enabling diverse color displays. This characteristic allows the color controller to precisely adjust colors according to different needs and scenarios in practical applications, providing strong support for color display and optical applications in various fields.

[0055] The conversion between CIE coordinate graphs and RGB values ​​can be calculated using the following formula. Given three normalized values ​​(x, y, and z) from the three color values, their positions in the CIE 1931 color space can be calculated using the following formula:

[0056]

[0057]

[0058]

[0059] Finally, based on the tristimulus values ​​(X, Y, and Z), the RGB values ​​are obtained through the following matrix:

[0060]

[0061] Figure 5 The reflection spectrum of the color controller at different polarization angles is visually demonstrated. Experiments were conducted using the parameters set in the above embodiment. As the polarization angle increases from 0° to 90°, the absorption peak of the reflection spectrum gradually increases from 558 nm to 615 nm, resulting in a redshift in the reflection spectrum. This change leads to a color change from purple to blue.

[0062] Figure 5 (b) is a CIE coordinate graph, which shows that as the polarization angle increases from 0° to 90°, the corresponding coordinate points in the CIE coordinate graph change clockwise from 1 to 10, and the path of color change can be clearly observed.

[0063] Figure 5 (c) further reveals the RGB values ​​corresponding to the color change under different polarization angles. As the polarization angle (α) increases from 0° to 90°, the intensity of the red channel R decreases sharply from 227 to 108, the intensity of the green channel G increases from 187 to 232, and the intensity of the blue channel B changes from 254 to 247, thus showing the process of color change from purple to green.

[0064] Figure 6This study demonstrates the effect of changing the major-minor axis ratio of prism structural units composed of aluminum / diamond on the visible light reflectance spectrum. Experiments were conducted using parameters set in the example. By adjusting the major-minor axis ratio (b / a) of the prism, color display can be controlled.

[0065] It is worth noting that, Figure 6 (a) As the ratio of major to minor axes increases from 0.6 to 1.0, the absorption peaks of the reflection spectrum can be observed at 480 nm, 518 nm, 558 nm, 594 nm, and 632 nm, respectively. With the increase of the ratio of major to minor axes, the positions of the absorption peaks in the reflection spectrum exhibit a redshift.

[0066] To more clearly illustrate the impact of changes in the major and minor axis ratios on color, this invention further provides RGB values ​​for different ratios. Figure 6 (b) It can be seen that changes in the ratio of the major and minor axes significantly affect the intensity of the red channel R. The intensity variation range of the red channel can reach 124, the intensity variation range of the green channel is 56, and the intensity variation range of the blue channel is smaller. This more clearly illustrates the process of color change from pink to blue.

[0067] This invention relates to a color controller composed of prism-shaped metal dielectric units and a metal film, belonging to the field of color display and optical materials and devices. The overall structure of this color controller consists of three layers from top to bottom: the upper and middle layers are arrays of periodically arranged aluminum / diamond prism-shaped units, and the lower layer is a silver film. Based on the interference and resonance effects of light, this structure has high reflectivity in the visible light range, giving it color rendering properties.

[0068] In the simulation experiment of this invention, the specific color of the reflected light can be controlled by changing the thickness of the intermediate dielectric layer, the ratio of the major and minor axes of the prism, and the polarization angle of the incident light. Increasing the thickness of the intermediate dielectric layer causes a blue shift in the resonance peak, while increasing the polarization angle and the ratio of the major and minor axes causes a red shift in the resonance peak. Since the designed color controller achieves color change through the modulation of the resonance peak rather than relying on traditional pigments or dyes, it has the advantages of stability and durability, showing extremely broad application prospects in electronic devices, optical sensors, smart displays, and other fields.

[0069] Obviously, the embodiments described above are only some embodiments of this application, not all embodiments. The accompanying drawings show preferred embodiments of this application, but do not limit the patent scope of this application. This application can be implemented in many different forms; rather, the purpose of providing these embodiments is to provide a more thorough and comprehensive understanding of the disclosure of this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing specific embodiments, or make equivalent substitutions for some of the technical features. Any equivalent structures made using the content of this application's specification and drawings, directly or indirectly applied to other related technical fields, are similarly within the scope of patent protection of this application.

Claims

1. A color controller composed of prism-shaped metal dielectric units, characterized in that: It includes a bottom silver film and multiple periodically arranged prism structure units on the bottom silver film; the prism structure unit includes a top aluminum film and an intermediate dielectric layer, the intermediate dielectric layer being a diamond layer; The prism structure unit is a quadrilateral prism. The prism structure unit and the parallel cross section of the underlying silver film are designed in a rhombus shape.

2. The color controller composed of prism-shaped metal dielectric units according to claim 1, characterized in that: The arrangement period of the prism structure units on the bottom silver film is 300 nm.

3. The color controller composed of prism-shaped metal dielectric units according to claim 1, characterized in that: The thickness of the underlying silver film is 300 nm.

4. The color controller composed of prism-shaped metal dielectric units according to claim 3, characterized in that: The thickness of the top aluminum film is 50 nm, and the thickness of the diamond layer is 16 nm.

5. The color controller composed of prism-shaped metal dielectric units according to claim 1, characterized in that: The major axis and minor axis of the prism structure unit are 50 nm and 40 nm, respectively.

6. The color controller composed of prism-shaped metal dielectric units according to claim 4, characterized in that: The top aluminum film has a refractive index of 1.372 in the visible light range, the middle diamond layer has a refractive index of 2.42, and the bottom silver film has a refractive index of 0.

288.

7. A method for fabricating a color controller based on the prism-shaped metal dielectric unit described in claim 1, characterized in that: Includes the following steps: 1) A silicon wafer of a certain thickness is used as a substrate, and a silver layer is deposited on the substrate using an electron beam evaporator to reflect sunlight; 2) Diamond and aluminum are deposited layer by layer using plasma-enhanced chemical vapor deposition to form an intermediate diamond layer and a top aluminum film; 3) The surface of the top aluminum film is coated with photoresist and exposed using a photolithography device through a diamond-shaped mask; 4) Clean the photoresist after the reaction and use plasma etching to etch the desired prism pattern on the aluminum surface; 5) The reflectance of the prepared metafabric sample in the ultraviolet, visible and near-infrared bands was measured by a UV-Vis-NIR spectrophotometer equipped with a diffuse integrating sphere to perform spectral detection of the color controller.

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