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

Abstract

The invention belongs to the field of color display and optical materials, and particularly discloses a color regulator composed of prismatic metal dielectric units and a preparation method thereof.The color regulator comprises a bottom layer silver film and a plurality of prismatic structure units periodically arranged and distributed on the bottom layer silver film; each prism structure unit comprises a top aluminum film and a middle dielectric layer, and the middle dielectric layer is a diamond layer. According to the invention, the intrinsic attribute of the material is ingeniously optimized through the periodically arranged prism structure units, so that the efficient selective absorption of visible light is realized, and the material has the advantages of controllability, stability, reliability and the like, and is suitable for multiple fields of electronic equipment, optical sensors, intelligent display and the like.

Description

Technical Field

[0001] The invention belongs to the field of color display and optical materials, and in particular relates to a color regulator composed of prismatic metal dielectric units and a preparation method thereof. Background Art

[0002] Color plays an important role in our daily lives. Traditional dyes and pigments mainly present colors by absorbing and reflecting light, but such colors appear dull, with unsatisfactory resolution and limited color gamut. In addition, these substances have poor chemical stability and are prone to fading in high temperature environments or under strong ultraviolet rays. In sharp contrast, structural colors have many advantages such as rich and diverse colors, high saturation, strong stability, and can achieve a relatively wide color gamut coverage, thus showing richer and more vivid color effects. Structural colors mainly reflect light of specific wavelengths by adjusting the interference and scattering of light. Since the birth of structural colors is due to the interaction of light waves, rather than a chemical absorption process, this feature makes its production process more environmentally friendly.

[0003] Traditional color controllers are usually limited to achieving color changes by adjusting geometric features such as shape, spacing or period. This method not only has a single method, but also lacks adjustability in the displayed color. More importantly, the color of these controllers remains unchanged under different polarized light, which limits their application range. Summary of the invention

[0004] In order to address the deficiencies of the prior art, the present invention aims to provide a color regulator composed of prismatic metal dielectric units. Through periodically arranged prismatic structural units, the intrinsic properties of the material are cleverly optimized, thereby achieving efficient and selective absorption of visible light. It has the advantages of controllability, stability and reliability, and is suitable for multiple fields such as electronic devices, optical sensors, and smart displays.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A color regulator composed of prismatic metal dielectric units comprises a bottom silver film and a plurality of prismatic structural units periodically arranged and distributed on the bottom silver film; the prismatic structural unit comprises a top aluminum film and an intermediate dielectric layer, and the intermediate dielectric layer is a diamond layer.

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

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

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

[0010] Preferably, the bottom silver film has a thickness of 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 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.

[0014] Correspondingly, the present invention also proposes a method for preparing a color regulator based on the above-mentioned prismatic metal dielectric unit, comprising the following steps:

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

[0016] 2) Plasma-enhanced chemical vapor deposition is used to deposit diamond and aluminum layer by layer to form a middle diamond layer and a top aluminum film;

[0017] 3) coating the surface of the top aluminum film with photoresist and exposing it through a diamond mask using a photolithography device;

[0018] 4) cleaning the reacted photoresist and etching the desired prism pattern on the aluminum surface using plasma etching;

[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 regulator.

[0020] The present invention has the following beneficial effects:

[0021] The present invention provides a color regulator composed of a prismatic metal dielectric structural unit and an underlying metal film, which provides an effective method for achieving sustainable and controllable color display. The color regulator fully utilizes the principles and advantages of structural color, has good controllability, and can adjust the color display according to different needs. It not only brings new breakthroughs and development opportunities for color display technology, but also provides more high-quality, environmentally friendly and diversified color solutions for many related fields, such as electronic equipment, optical sensors, smart displays, etc. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0023] Figure 2 is the reflection spectrum of the color regulator of the present invention in the visible light range under the x-polarization and y-polarization modes;

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

[0025] Figure 4 The effects of different dielectric layer thicknesses on the reflection spectrum under x-polarization (a) and y-polarization (c) conditions of the present invention, and the corresponding CIE coordinate diagrams;

[0026] Figure 5 This is a reflection spectrum diagram of the color regulator of the present invention at different polarization angles;

[0027] Figure 6 It is the reflection spectrum and corresponding RGB numerical diagram of the color regulator of the present invention under different prism major and minor axis ratios in x polarization.

[0028] Description of the accompanying drawings:

[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 (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 16nm. DETAILED DESCRIPTION

[0032] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not intended to limit the scope of use of the present invention.

[0033] like Figure 1-5 As shown, in order to broaden the means of regulating color display, the present invention introduces a regulation mechanism that is completely different from the traditional color regulator, and specifically proposes a color regulator composed of a prismatic metal dielectric unit, including a bottom silver film and a plurality of prismatic structural units periodically arranged and distributed on the bottom silver film; the prismatic structural unit includes a top aluminum film and an intermediate dielectric layer, and the intermediate dielectric layer is a diamond layer. The electromagnetic resonance characteristics of this three-layer structure can be used to achieve reflection of specific wavelengths in the visible light range. This color regulator can not only change the color by adjusting the structural parameters, but more importantly, it can achieve color changes by changing the polarization angle of light.

[0034] The advantage of this color regulator is that it does not rely on changes in physical structure, but flexibly controls the color through the polarization state of light, which improves the flexibility and accuracy of color regulation. Since it does not rely on changes in physical size, it has higher stability and durability. In addition, since the intermediate medium layer of the regulator uses inorganic material diamond, it not only has a longer service life, but also maintains stable performance under high temperature and ultraviolet irradiation.

[0035] The present invention defines the upper surface of the bottom silver film as the xy plane, and the direction perpendicular to the upper surface is defined as the z direction. The shape of the prism structure unit is a quadrilateral prism with a diamond-shaped cross-section in the xy plane. The generation and regulation of color mainly rely on the interference and resonance effects of light. The asymmetric design of the prism structure unit of the present invention provides a basis for the regulation of color display. In specific implementation, the thickness of the intermediate dielectric layer, polarization angle, and the ratio of the major and minor axes of the prisms of different models of prism structure units can effectively change the optical path, affect the interference effect, and thus realize the display of specific colors. The greater the thickness of the intermediate dielectric layer, the more blue-shifted the resonance peak will be during the color regulation process, and the increase in the polarization angle and the ratio of the major and minor axes will cause the resonance peak to red-shift.

[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 axis and minor axis 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 arrangement period of the prism structure units in the xy plane is 300nm. The electromagnetic interaction between the prism structure units with this periodic design plays a vital role in the color regulator to realize its function.

[0039] Correspondingly, based on the color controller composed of the above-mentioned prismatic metal dielectric unit, the present invention also proposes a method for preparing the color controller, comprising the following steps:

[0040] 1) Using a silicon wafer of suitable thickness as a substrate, a silver layer is deposited on the substrate by an electron beam evaporator to reflect sunlight;

[0041] 2) Plasma-enhanced chemical vapor deposition is used to deposit diamond and aluminum layer by layer to form a middle diamond layer and a top aluminum film;

[0042] 3) coating the surface of the top aluminum film with photoresist and exposing it through a diamond mask using a photolithography device;

[0043] 4) cleaning the reacted photoresist and etching the desired prism pattern on the aluminum surface using plasma etching;

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

[0045] Simulation experiment

[0046] The present invention uses three-dimensional finite element multi-physics simulation software COMSOL Multiphysics for simulation. During simulation, only one unit of the prismatic structure unit needs to be calculated, and an infinite array structure is simulated by setting a periodic boundary in the plane direction. Similarly, the upper surface of the bottom silver film is defined as the xy plane, and the direction perpendicular to the upper surface is defined as the z direction. The plane electromagnetic wave is incident along the z axis, and the electric field is incident along the y axis. Periodic boundary conditions are used in the x and y axis directions, and a perfect matching layer is used in the z direction to eliminate non-physical reflections at the boundary. The grid division is set to refine, and then the frequency domain is scanned and the absorption and reflection results are calculated respectively, so as to obtain the corresponding absorption and reflection spectra.

[0047] In order to study the influence of the thickness of the intermediate dielectric layer, polarization angle, and the ratio of the major and minor axes of the aluminum / diamond prism on the color regulator of the present invention, in the simulation experiment, in addition to the variable parameters, the thickness of the intermediate dielectric layer, polarization angle, and the ratio of the major and minor axes of the aluminum / diamond prism are changed in sequence while keeping other parameters the same. The simulation experiment results are as follows:

[0048] Figure 2 The reflection spectrum of the color controller of the present invention in the visible light band under the x-polarization and y-polarization modes is shown in the test with the parameters set in the above embodiment. From the reflection spectrum, it can be found that the corresponding resonance peaks under the x-polarization and y-polarization modes are located at 558nm and 615nm respectively, and the corresponding colors are purple and green respectively. This significant feature shows that the color controller composed of the prismatic metal dielectric structure unit and the bottom metal film has a color display function and has the characteristics of polarization regulation.

[0049] Figure 3 The influence of different intermediate dielectric layer materials on the reflectance spectrum in the visible light range is described. Experiments are conducted with the parameters set in the above embodiment, and the materials of the intermediate dielectric layer are changed.

[0050] in Figure 3(a) shows the visible light reflectance spectra of different intermediate dielectric layer materials under x-polarized light. Figure 3 It can be clearly seen in (a) that the change in the reflectance spectrum is huge as the intermediate dielectric material changes. Under x-polarized light, the corresponding reflectance spectrum peak positions of diamond, silicon dioxide, silicon nitride, and hafnium dioxide are 558nm, 496nm, 567nm, and 505nm, respectively; under y-polarized light, the corresponding reflectance spectrum peak positions of diamond, silicon dioxide, silicon nitride, and hafnium dioxide are 615nm, 551nm, 623nm, and 558nm, respectively. It can be found that compared with other dielectric materials, diamond has a relatively wide spectral regulation range of 57nm, which can display richer and more diverse colors.

[0051] Figure 4 The effect of the change of the thickness of the intermediate dielectric layer on the reflectance spectrum in the visible light range is described. Experiments are conducted with the parameters set in the above embodiment, and the thickness of the intermediate dielectric layer is changed.

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

[0053] Corresponding CIE coordinates Figure 4 (c) The color change trend can be observed more clearly. The points corresponding to different thicknesses in the CIE coordinate diagram show a counterclockwise change trend from A to E. Figure 4 (b) It can be clearly seen that when other parameters remain unchanged, as the thickness of the intermediate dielectric layer increases from 12nm to 20nm, the corresponding reflection spectrum peak positions are 675nm, 641nm, 615nm, 594nm, and 576nm, respectively. It can be found that the reflection spectrum of y-polarized light has a blue shift phenomenon. The color also changes from yellow-green to dark blue accordingly.

[0054] Corresponding CIE coordinates Figure 4(d) It can be more clearly observed that the points corresponding to the color change trend show a counterclockwise change trend from A to E. These observations strongly indicate that the change in the thickness of the dielectric layer can achieve a blue shift in the reflection spectrum, thereby achieving a variety of color displays. This feature enables the color regulator to accurately control the color according to different needs and scenarios in practical applications, providing strong support for color display and optical applications in various fields.

[0055] The conversion method between CIE coordinates and RGB values ​​can be calculated by the following formula. Given three normalized values ​​(x, y and z) from the tristimulus values, the position in the CIE 1931 color space can be calculated by the following formula:

[0056]

[0057]

[0058]

[0059] Finally, according to the three stimulus values ​​(X, Y and Z), the RGB value is obtained through the following matrix:

[0060]

[0061] Figure 5 The corresponding reflection spectra of the color controller at different polarization angles are intuitively displayed. The experiment was carried out with 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 558nm to 615nm, and the reflection spectrum shows a red shift phenomenon, which in turn causes the color to change from purple to blue.

[0062] Figure 5 (b) is the CIE coordinate diagram, which shows that as the polarization angle increases from 0° to 90°, the corresponding coordinate points in the CIE coordinate diagram 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 changes at 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, indicating the color change process from purple to green.

[0064] Figure 6The effect of the change in the ratio of the major axis to the minor axis of the prism structure unit composed of aluminum / diamond on the visible light reflectance spectrum is demonstrated. The experiment was conducted with the parameters set in the embodiment. By adjusting the ratio of the major axis to the minor axis (b / a) of the prism, the color display can be regulated.

[0065] It is worth noting that Figure 6 (a) When the ratio of the major axis to the minor axis increases from 0.6 to 1.0, the absorption peaks of the reflection spectrum are observed to be 480nm, 518nm, 558nm, 594nm, and 632nm. As the ratio of the major axis to the minor axis increases, the absorption peak position of the reflection spectrum shows a red shift phenomenon.

[0066] In order to more clearly describe the effect of the change in the ratio of the major axis to the minor axis on the color, the present invention further provides RGB values ​​under different ratios. Figure 6 (b) It can be seen that the change in the ratio of the major axis to the minor axis will greatly affect the intensity of the red channel R. The intensity range of the red channel can reach 124, the intensity range of the green channel is 56, and the intensity range of the blue channel is smaller. This more clearly shows the color change process from pink to blue.

[0067] The present invention relates to a color controller composed of a prismatic metal dielectric unit and a metal film, and belongs to the field of color display and optical materials and devices. The overall structure of the color controller is composed of three layers from top to bottom: the upper layer and the middle layer are respectively a prismatic structure unit array composed of periodically arranged aluminum / diamond, and the lower layer is a metal silver film. Based on the interference and resonance effects of light, this structure has a high reflectivity in the visible light range, so that it has color rendering characteristics.

[0068] In the simulation experiment of the present invention, by changing the thickness of the intermediate dielectric layer, the ratio of the major and minor axes of the prisms, and the polarization angle of the incident light, the specific color of the reflected light can be controlled and displayed. Increasing the thickness of the intermediate dielectric layer will cause the resonance peak to blue shift, while increasing the polarization angle and the ratio of the major and minor axes will cause the resonance peak to red shift. Since the designed color regulator realizes color transformation by modulating the resonance peak instead of relying on traditional pigments or dyes, it has the advantages of stability and durability, and shows extremely broad application prospects in the fields of electronic equipment, optical sensors, smart displays, etc.

[0069] Obviously, the embodiments described above are only some embodiments of the present application, rather than all embodiments. The preferred embodiments of the present application are given in the accompanying drawings, but they do not limit the patent scope of the present application. The present application can be implemented in many different forms. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present application more thorough and comprehensive. Although the present application is described in detail with reference to the aforementioned embodiments, for those skilled in the art, it is still possible to modify the technical solutions recorded in the aforementioned specific implementation methods, or to perform equivalent replacement of some of the technical features therein. Any equivalent structure made using the contents of the specification and drawings of this application, directly or indirectly used in other related technical fields, is similarly within the scope of patent protection of this application.

Claims

1. A color controller composed of prismatic metal dielectric units, characterized in that: It comprises a bottom silver film and a plurality of prism structure units periodically arranged and distributed on the bottom silver film; the prism structure unit comprises a top aluminum film and an intermediate dielectric layer, and the intermediate dielectric layer is a diamond layer.

2. The color controller composed of prismatic metal dielectric units according to claim 1, characterized in that: The prism structure unit is in the shape of a quadrilateral prism.

3. The color controller composed of prismatic metal dielectric units according to claim 2, characterized in that: The parallel cross-section of the prism structure unit and the bottom silver film is designed in a diamond shape.

4. The color controller composed of prismatic 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.

5. The color controller composed of prismatic metal dielectric units according to claim 1, characterized in that: The thickness of the bottom silver film is 300 nm.

6. The color controller composed of prismatic metal dielectric units according to claim 5, characterized in that: The thickness of the top aluminum film is 50 nm, and the thickness of the diamond layer is 16 nm.

7. The color controller composed of prismatic metal dielectric units according to claim 3, characterized in that: The major axis and minor axis of the prism structural unit are 50 nm and 40 nm, respectively.

8. The color controller composed of prismatic metal dielectric units according to claim 6, characterized in that: 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.

9. A method for preparing a color controller based on the prismatic metal dielectric unit of claim 1, characterized in that: The following steps are involved: 1) Using a silicon wafer of a certain thickness as a substrate, a silver layer is deposited on the substrate by an electron beam evaporator to reflect sunlight; 2) Plasma-enhanced chemical vapor deposition is used to deposit diamond and aluminum layer by layer to form a middle diamond layer and a top aluminum film; 3) The top aluminum film is coated with photoresist and exposed through a diamond mask using a photolithography device; 4) cleaning the reacted photoresist and etching the desired prism pattern on the aluminum surface using plasma etching; 5) The reflectance of the prepared metafabric samples 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 regulator.

Images