CN221613055U

CN221613055U - Enhanced reflection type metal medium structural color film and F-P resonant cavity

Info

Publication number: CN221613055U
Application number: CN202420087282.2U
Authority: CN
Inventors: 储著伟; 王梦东; 李延凯; 吴强; 卜轶坤
Original assignee: Xiamen Shandie Technology Co ltd
Current assignee: Xiamen Shandie Technology Co ltd
Priority date: 2024-01-15
Filing date: 2024-01-15
Publication date: 2024-08-27
Anticipated expiration: 2034-01-15

Abstract

The utility model discloses a reflection-enhanced metal dielectric structural color film and an F-P resonant cavity. The structural color film is used for an F-P cavity structure and is characterized by comprising an absorption layer, a dielectric layer and a metal layer; an enhanced reflection layer is arranged between the dielectric layer and the metal layer; the enhanced reflection layer is formed by stacking at least one group of enhanced films, each group of enhanced films is formed by stacking a high-refractive-index dielectric film and a low-refractive-index dielectric film, wherein the thickness of each dielectric film is lambda ₀/4, and lambda ₀ is the F-P cavity reflection center wavelength. The utility model provides a reflection-enhanced metal medium structure color film, which can further improve the reflectivity of a traditional F-P cavity structure metal medium structure color film, compress the reflection bandwidth of a target reflection band and realize higher color brightness and saturation than the traditional metal medium structure color film.

Description

Enhanced reflection type metal medium structural color film and F-P resonant cavity

Technical Field

The utility model relates to the technical field of structural color films, in particular to a reflective metal dielectric structural color film and an F-P resonant cavity.

Background

In daily industrial technology, colors play an important role and are classified into two types, chemical colors and physical colors according to the generation mechanism. Chemical colors are generated by partial absorption of 380nm to 780nm light waves by chromophores, while physical colors are generated by modulating 380nm to 780nm light waves by a material structure, such as interference effects, diffraction phenomena, and scattering phenomena of light, also called structural colors.

The optical film is one of important materials for generating structural color, and the structure used as the structural color of the film is known to be a metal dielectric material stacked film system based on an F-P cavity structure, a structural color film system designed by using an all-dielectric material, and a structural color film which is manufactured into a nano array, a rectangular array and the like by complex processes such as photoetching and etching on the basis of the structure and is used for obtaining higher saturation. Although some researches have been carried out on structural color films in the industry at present, the conventional film structural color film systems have respective corresponding defects.

In patent CN103744138A, CN109491002A, CN110412672B, visible light is coupled and resonated at the surface of the material by a nanocircular hole array or a nano cylindrical array to achieve high reflection and high absorption, thereby displaying a specific color. However, the method often needs to use methods such as reactive ion etching, wet etching, atomic layer deposition, photoetching and the like, and compared with the method for preparing the photonic crystal by only electron beam evaporation, the method has complex manufacturing flow and greatly improves the preparation cost. In the CN116540331a, a thin film structure is designed by stacking high and low refractive index all-dielectric materials, and the design of the reflective structure color is performed by using all-dielectric materials, where the reflectivity and the reflection bandwidth depend on the number of layers of the film and the ratio of the high and low refractive index materials, and the obtainable high reflectivity depends on the stack of the number of layers of the film. Furthermore, due to its all-dielectric properties, it is a corresponding high transmission interval for the low reflection band, which is strongly dependent on the background color of the substrate in color display. Therefore, the total thickness of the film with the full-medium structure is thicker, and higher requirements are also put on the preparation process. The films also exhibit relatively poor reflective color saturation on light colored substrates from the standpoint of their spectral characteristics.

Structural color films based on F-P cavity construction are further divided into symmetrical and asymmetrical types. The symmetrical structure is composed of an absorption layer/a medium layer/a metal layer/a medium layer/an absorption layer, and the asymmetrical structure is composed of an absorption layer/a medium layer/a metal layer. Related patents such as CN100482746C, CN 104730737B all propose a metal dielectric structural color film based on F-P cavity construction. The reflective layer is generally formed by high-reflectivity metals such as aluminum, silver, gold, copper, platinum, titanium, chromium, nickel, cobalt, rhodium, niobium and the like and alloys thereof, wherein the metals contain high-reflectivity metals such as aluminum, silver, gold, copper and the like, the single-layer basic reflectivity of the metals is more than 90 percent, the high-reflectivity metals such as silver and gold have the problem of high cost, and the aluminum has the problem of poor environmental stability and is easy to generate hydrolysis reaction in a humid environment although the cost is low. Neutral metals such as titanium, chromium, tantalum, niobium, nickel and the like are adopted, and the environment stability is better, but the metals belong to neutral metals, and the reflectivity of the metals in the visible light part is about 50-60%, which is far less than that of the metals silver and gold, namely, the visible light with the reflectivity of more than 90%. Secondly, al and Ag are selected as high-reflectivity materials, and oxidation reaction is easy to occur between the high-reflectivity materials and the upper medium oxide in the deposition process due to the reactivity of metals, so that the defects of reflectivity reduction, even spectral shift and the like are caused, and the preparation difficulty is greatly improved. As a reflective metal layer in the F-P cavity structure, the use of neutral metal leads to a reduction in the reflectivity of the overall structure color film system, ultimately resulting in a low color brightness. Metal layer

Disclosure of utility model

Therefore, the utility model aims to provide the enhanced reflection type metal medium structural color film, the reflectivity of the metal layer can be further improved by introducing the enhanced reflection layer on the basis of the traditional F-P metal medium structure, and the introduction of the enhanced reflection layer can compress the reflection bandwidth of the target reflection band together with the original medium layer, so that the color brightness and saturation superior to those of the traditional F-P cavity structure are realized.

According to one aspect of the present utility model, there is provided a reflective enhanced metal dielectric structural color film comprising: comprises an absorption layer, a dielectric layer and a metal layer;

A dielectric reflection enhancement film stack is arranged between the dielectric layer and the metal layer;

The enhanced reflection layer is formed by stacking at least one group of enhanced films, each group of enhanced films is formed by stacking a high-refractive-index dielectric film and a low-refractive-index dielectric film, wherein the thickness of each dielectric film is lambda ₀/4, and lambda ₀ is the F-P cavity reflection center wavelength.

In the above technical solution, this embodiment proposes a novel thin film structure color structure composed of an absorption layer, a dielectric reinforced film stack, and a metal layer. The metal layer of the structure solves the problem of lower reflectivity of the traditional metal layer by introducing a dielectric reinforced film stack. The medium enhancement film stack introduced can jointly adjust the reflection bandwidth with the original medium layer, firstly can enhance the reflectivity of the metal layer, secondly, the enhancement reflection layer is formed by the medium film, so that the enhancement reflection layer and the medium layer are jointly overlapped to be regarded as a thickened medium layer, the interference optical path of light in the medium is enhanced, the high-order interference is realized, the reflection bandwidth is compressed, the color saturation is improved, and the color brightness and the saturation of the structural color film which are higher than those of the traditional F-P cavity structure are realized. The specific film layer structure designed in this embodiment may be a symmetrical structure or an asymmetrical structure. For an asymmetric structure, a metal layer M/a medium reinforced film stack D1/a medium layer D2/an absorption layer A are deposited from the substrate upwards; for the symmetrical structure, the basic structure of the absorption layer A/medium layer D2/medium enhancement film stack D1/metal layer M/medium enhancement film stack D1/medium layer D2/absorption layer A can be adopted for construction.

In some embodiments, the low refractive index dielectric film in the enhancement film stack is closer to the metal layer than the high refractive index dielectric film.

In the technical scheme, the dielectric reflection enhancement film stack is added between the metal layer and the dielectric layer, so that the effect of enhancing the reflectivity of the whole film system is achieved. The film layer structure uses the stacking principle of lambda ₀/4 film stack, namely, a metal film layer is plated with two layers of lambda ₀/4 dielectric films with refractive index of n ₁、n₂, and n ₂ is tightly attached to metal, so that the admittance of lambda ₀ is as follows in normal incidence: its reflectivity is Can be seen inWhen the total reflectivity is larger than that of the bottom metal layer, and the ratio isThe larger the increase in reflectivity, the more the above condition is satisfied, and the refractive index n ₁ is required to be larger than the refractive index n ₂, that is, the dielectric material near the metal layer is a low refractive index dielectric thin film material with the refractive index n ₂. Therefore, the reflection enhancement strength of the layer can be adjusted by increasing the stacking times of the enhanced reflection layer or increasing the refractive index difference of the high-refractive index material and the low-refractive index material.

In some embodiments, the high refractive index dielectric film is a material having a refractive index between 1.7 and 3 at a wavelength in the range of 380nm to 780 nm.

In the above technical scheme, the present embodiment provides that the material with the refractive index between 1.7 and 3 in the range of 380nm to 780nm is defined as the high refractive index material. The range of the high refractive index material setting of this embodiment needs two points to be considered: the utility model aims at the structural color film, and the visible light wave band is considered from the spectrum for color evaluation, and the wavelength range is 380nm-780nm, so the wavelength range is limited. Secondly, the refractive index is set to be 1.7-3, and mainly, conventional transparent dielectric film materials are also considered, and the general highest refractive index is about 2.7, and the lowest refractive index is about 1.3, so that the high refractive index material is defined as 1.7-3 conventionally. However, the innovation point of the utility model is that an enhanced reflection layer is introduced into the traditional FP cavity metal layer, and the enhanced reflection layer is overlapped by two dielectric films with high and low refractive indexes to realize the required beneficial effect, so that a high-low classification is made between 1.2 and 3 in the conventional optical film dielectric material, and a 1.7 is taken as a demarcation value, so that the final formed structure effect is optimal.

In some embodiments, the material of the high refractive index dielectric film comprises: tantalum oxide (Ta ₂O₅), titanium oxide (TiO ₂), hafnium oxide (HfO ₂), zirconium oxide (ZrO ₂), niobium oxide (Nb ₂O₅), lanthanum titanate (La ₂Ti₂O₇), yttrium oxide (Y ₂O₃), zinc sulfide (ZnS), silicon nitride (Si ₃N₄), bismuth oxide (Bi ₂O₃), cerium oxide (CeO ₂), chromium oxide (Cr ₂O₃), magnesium oxide (MgO), neodymium oxide (Nd ₂O₃), zinc oxide (ZnO) or a mixture of at least two of the foregoing materials

In the technical scheme, the material has the advantages that the refractive index is between 1.7 and 3, the material is stable in growth and high in stacking density, and has low absorption in a visible light wave band and high transparency.

In some embodiments, the low refractive index dielectric film is a material with a refractive index between 1.2 and 1.7 having a wavelength in the range of 380nm to 780 nm.

In the above technical solution, the present embodiment specifies that a material having a refractive index ranging from 1.2 to 1.7 in the range of 380nm to 780nm is defined as a low refractive index material. The range of low refractive index material settings in this embodiment requires two points to consider: the utility model aims at the structural color film, and the visible light wave band is considered from the spectrum for color evaluation, and the wavelength range is 380nm-780nm, so the wavelength range is limited. Secondly, the refractive index is defined to be 1.2-1.7, and mainly, conventional transparent dielectric film materials are also considered, and the general highest refractive index is about 2.7, and the lowest refractive index is about 1.3, so that the low refractive index material is defined as 1.2-1.7 conventionally. However, the innovation point of the utility model is that an enhanced reflection layer is introduced into the traditional FP cavity metal layer, and the enhanced reflection layer is overlapped by two dielectric films with high and low refractive indexes to realize the required beneficial effect, so that a high-low classification is made between 1.2 and 3 in the conventional optical film dielectric material, and a 1.7 is taken as a demarcation value, so that the final formed structure effect is optimal.

In some embodiments, the low refractive index dielectric film material comprises: silica (SiO ₂), alumina (Al ₂O₃), magnesium fluoride (MgF ₂), aluminum fluoride (AlF ₃), cerium fluoride (CeF ₃), lanthanum chloride (LaF ₃), sodium hexafluoroaluminate (Na ₃AlF₆), neodymium fluoride (NdF ₃), barium fluoride (BaF ₂), calcium fluoride (CaF ₂), or lithium fluoride (LiF)), or a mixture of at least two of the foregoing.

In the technical scheme, the material has the advantages that the refractive index is between 1.2 and 1.7, and the selected material has low absorption in the visible light band and high transparency. The method is suitable for being combined and overlapped with the medium high refractive index material so as to realize the interference enhancement of reflection without introducing absorption.

In some embodiments, the dielectric layer is a material with a refractive index between 1.2 and 3.0 in the wavelength range of 380nm to 780nm, and the thickness is controlled between 50nm and 1000 nm.

In the technical scheme, the intermediate medium layer D2 in the structure can be selected from all-medium thin film materials with refractive indexes between 1.2 and 3 in the wavelength range of 380 nm-780 nm, and structural color thin films with different colors can be designed by adjusting the materials and the thickness of the layer. The thickness of the layer is between 50nm and 1000nm, preferably between 100nm and 800 nm.

In some embodiments, the metal layer is elemental metal and mixtures thereof, and has a thickness between 20nm and 200 nm.

In the above technical solution, the metal layer in the structure may be various metal elements, and may be a high reflection metal in the conventional F-P metal layer, such as: gold, silver, or metals with low reflectivity such as: titanium, tantalum, iron, aluminum, nickel, chromium, niobium, and the like. The reflecting layer in the structure plays the same role as the reflecting layer in the traditional F-P cavity structure, and the reflecting layer improves the reflectivity of the whole film system and is used as a bottom reflecting layer. The use of low reflectivity metals, although not as reflective as high reflectivity metals, can increase the overall reflectivity of the film system by enhancing the dielectric layer, and can reduce the industrial cost at the same time, providing a solution for the use of other metals in the structural color reflective layer. The thickness of the reflecting layer is required to be larger than 20nm, and is not required to be too thick to be smaller than 200nm, and the thickness range of 40nm-150nm is generally preferred, and the thickness is not easy to be too thick mainly for reducing the manufacturing cost, and meanwhile, the scattering loss caused by too thick film layer is reduced.

In some embodiments, the structural color film further includes an absorption layer, where the absorption layer is disposed on a side of the dielectric layer away from the enhanced reflection layer, and is made of a metal simple substance or a mixture thereof or a semiconductor material with a certain absorption characteristic, and has a thickness of 3nm-30nm, preferably 5nm-20nm.

In the above technical solution, the absorption layer in the structure is made of metal simple substance material or a mixture thereof, and metal with partial absorption property is generally selected as the preferred material of the layer. Common materials are as follows: chromium, titanium, tantalum, nickel, niobium, cobalt, iron, or mixtures thereof. The metal of the layer generally has the characteristics of high transmittance and low reflectivity when the thickness is less than 20nm, which is quite opposite to the characteristics when the thickness of the material is greater than 100nm, and partial absorption is accompanied, so that the metal is an excellent choice as a top saturation control absorption layer. The thickness of the layer is between 3nm and 30nm, preferably between 5nm and 20nm, depending on the material properties required above.

According to another aspect of the present utility model, there is provided an F-P resonator comprising an enhanced reflective metal dielectric structural color film as described above.

Drawings

In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the utility model, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of a symmetric film system for enhancing structural color films of reflective metal dielectrics according to the present utility model.

FIG. 2 is a schematic diagram of an asymmetric film system for enhancing structural color films of reflective metal dielectrics according to the present utility model.

FIG. 3 is a reflection spectrum under normal incidence of one embodiment of a color film of enhanced reflection type metal dielectric structure according to the present utility model.

FIG. 4 is a chromaticity diagram at normal incidence for one embodiment of a color film of an enhanced reflective metal dielectric structure of the present utility model.

FIG. 5 is a diagram showing the reflection spectrum at normal incidence of a second embodiment of a color film with enhanced reflection metal dielectric structure according to the present utility model.

FIG. 6 is a chromaticity diagram at normal incidence for a second embodiment of a color film of an enhanced reflective metal dielectric structure of the present utility model.

FIG. 7 is a reflection spectrum under normal incidence for a third embodiment of a color film of enhanced reflection type metal dielectric structure according to the present utility model.

FIG. 8 is a chromaticity diagram at normal incidence illustrating a third exemplary color film of an enhanced reflective metal dielectric structure according to the present utility model.

FIG. 9 is a graph showing the reflection spectrum at normal incidence for a fourth embodiment of a color film of an enhanced reflection type metal dielectric structure according to the present utility model.

FIG. 10 is a chromaticity diagram at normal incidence for a fourth embodiment of an enhanced reflective metal dielectric structural color film of the present utility model.

FIG. 11 is a diagram showing the reflection spectrum at normal incidence for a fifth embodiment of a color film of an enhanced reflective metal dielectric structure according to the present utility model.

FIG. 12 is a chromaticity diagram at normal incidence for a fifth embodiment of an enhanced reflective metal dielectric structural color film of the present utility model.

Detailed Description

The utility model is described in further detail below with reference to the drawings and examples. It is specifically noted that the following examples are only for illustrating the present utility model, but do not limit the scope of the present utility model. Likewise, the following examples are only some, but not all, of the examples of the present utility model, and all other examples, which a person of ordinary skill in the art would obtain without making any inventive effort, are within the scope of the present utility model.

The utility model provides an enhanced reflection type metal medium structure color film, which can further improve the reflectivity of a metal layer in a main wavelength band of color, compress the reflection bandwidth of the main wavelength reflection band and realize higher color brightness and saturation.

The utility model provides a novel film structure color which is formed by an absorption layer, a dielectric reinforced film stack and a metal layer. The structure solves the problem of lower reflectivity of the traditional metal layer by introducing the dielectric enhancement film stack. The medium enhancement film stack introduced simultaneously can adjust the reflection bandwidth together with the original medium layer, and improve the color saturation, so that the color brightness and the saturation of the structural color film are higher than those of the traditional F-P cavity structure.

Referring to fig. 1 and 2, the specific film structure of the present utility model may be a symmetrical structure or an asymmetrical structure. For an asymmetric structure, a metal layer M dielectric enhanced film stack D1/a dielectric layer D2/an absorption layer A is deposited from the substrate upwards; for the symmetrical structure, the basic structure of the absorption layer A/medium layer D2/medium enhancement film stack D1/metal layer M/medium enhancement film stack D1/medium layer D2/absorption layer A can be adopted for construction.

The dielectric reinforced film stack D1 in the film system structure is formed by stacking a high-refractive-index dielectric layer H and a low-refractive-index dielectric layer L. The larger the number of stacked periods n, the higher the dominant wavelength reflectivity of the spectrum and the narrower the corresponding reflection bandwidth. Therefore, the symmetrical and asymmetrical film structures of the present utility model can be represented by symbols: sub/A/D2/(HL) ≡n/M/(LH) ≡n/D2/A; sub/M/(LH)/(n/D2/A) where Sub represents the substrate. Wherein the material having a refractive index of 1.7-3 in the range of 380nm to 780nm is defined as a high refractive index material such as tantalum oxide (Ta ₂O₅), titanium oxide (TiO ₂), hafnium oxide (HfO ₂), Zirconium oxide (ZrO ₂), niobium oxide (Nb ₂O₅), lanthanum titanate (La ₂Ti₂O₇), yttrium oxide (Y ₂O₃), Zinc sulfide (ZnS), silicon nitride (Si ₃N₄), bismuth oxide (Bi ₂O₃), cerium oxide (CeO ₂), chromium oxide (Cr ₂O₃), Materials such as magnesium oxide (MgO), neodymium oxide (Nd ₂O₃), and zinc oxide (ZnO); Materials with refractive indices in the range of 380nm to 780nm defined as 1.2-1.7 are low refractive index materials, such as silica (SiO ₂), alumina (Al ₂O₃), magnesium fluoride (MgF ₂), aluminum fluoride (AlF ₃), Cerium fluoride (CeF ₃), lanthanum chloride (LaF ₃), sodium hexafluoroaluminate (Na ₃AlF₆), neodymium fluoride (NdF ₃), Barium fluoride (BaF ₂), calcium fluoride (CaF ₂), lithium fluoride (LiF), or the like. By adjusting the optical thickness of the medium layers with high and low refractive indexes, the whole layer can play roles of reflection enhancement and compression reflection bandwidth, and the effects of enhancing color brightness and adjusting saturation are achieved. The thickness of the high-low refractive index layer of the film stack is generally 1/4 of the optical thickness of the reflection center wavelength of the enhancement required, and then the adjustment range of the optical thickness of the film stack is adjusted according to the brightness and saturation requirements of the required color, the adjustment range of the optical thickness of the film stack is based on the quarter thickness of the main reflection center wavelength lambda of the structural color film, and the optical thickness is changed between 0.5 quarter thickness and 1.5 quarter thickness.

The intermediate medium layer D2 in the structure is used as a main tone control layer of the structural color film, a medium film material is selected, and a full medium film material with the refractive index between 1.2 and 3 in the wavelength range of 380 nm-780 nm is defined. In order to achieve the desired color characteristics, different color structural color films can be designed by adjusting the material and thickness of the layer. The layer is used as a main tone control layer, and the thickness of the layer is between 50nm and 1000nm, preferably between 100nm and 800 nm.

The metal layer M in the structure can be made of metal simple substance or mixture of metal simple substances, and can be made of high reflection metal in the traditional F-P metal layer, such as: gold, silver, aluminum, metals with lower reflectivity such as: titanium, tantalum, iron, nickel, chromium, niobium, and the like. The reflecting layer in the structure plays the same role as the reflecting layer in the traditional F-P cavity structure, and the reflecting layer improves the reflectivity of the whole film system and is used as a bottom reflecting layer. The metal with low reflectivity is lower than the metal with high reflectivity, but the overall reflectivity of the film system can be improved through the dielectric reinforced film stack, meanwhile, the industrial cost can be reduced, a solution is provided for the application of other metals in the structural color reflecting layer, and the special partial absorption advantage of the material is exerted under the condition that the overall reflectivity is not reduced. The physical thickness of the layer is between 20nm and 200nm, the reflectivity is obviously reduced when the physical thickness is too thin, the light transmittance is increased, the scattering loss of the thin film is increased when the physical thickness is too thick, the reflection is reduced when the physical thickness is too thick, and the preferable thickness range is between 40nm and 150 nm.

The absorption layer in the structure is made of metal simple substance materials and mixtures thereof or semiconductor materials with certain absorption characteristics, and metals with partial absorption characteristics are generally selected as the preferred materials of the layer. Common materials are as follows: chromium, titanium, tantalum, nickel, niobium, cobalt, iron, silicon, germanium, and the like. This layer is an excellent choice as a top saturation control absorber layer because it generally exhibits high transmittance, low reflectance properties at thicknesses less than 20nm, which is quite opposite to those of the present material at thicknesses greater than 100nm, while also being accompanied by partial absorption. The thickness of the layer is between 3nm and 30nm, preferably between 5nm and 20nm, depending on the material properties required above.

The substrate material of the utility model adopts a highly polished rigid glass substrate, a stainless steel substrate and an aluminum alloy substrate, and can also adopt one of polyethylene terephthalate (PET), cellulose Triacetate (TAC), polymethyl methacrylate (PMMA), polycarbonate/polymethyl methacrylate composite material (PC/PMMA), polyimide (PI), polypropylene (PP), polyvinyl chloride (PVC), polyvinyl butyral (PVB), ethylene vinyl acetate copolymer (EVA) or polyurethane elastomer (TPU), polytetrafluoroethylene (PTFE), fluoroethyl propylene (FEP), polyvinylidene fluoride (PVDF) and other optical plastic substrates.

The structure of the embodiment achieves the effect of enhancing the reflectivity of the whole film system by adding the dielectric reflection enhancing film stack between the metal layer and the dielectric layer. The film layer structure uses the stacking principle of lambda ₀/4 film stack, namely, a metal film layer is plated with two layers of lambda ₀/4 dielectric films with refractive index of n ₁、n₂, and n ₂ is tightly attached to metal, so that the admittance of lambda ₀ is as follows in normal incidence:

its reflectivity is

From the above, it can be seen thatWhen the total reflectivity is larger than that of the bottom metal layer, and the ratio isThe larger the increase in reflectivity, the more the above condition is satisfied, and the refractive index n ₁ is required to be larger than the refractive index n ₂, that is, the dielectric material near the metal layer is a low refractive index dielectric thin film material with the refractive index n ₂. Therefore, the reflection enhancement strength of the layer can be adjusted by increasing the stacking times of the enhanced reflection layer or increasing the refractive index difference of the high-refractive index material and the low-refractive index material.

The reflection enhancing layer not only plays a role in reflection enhancement, but also can be equivalent to a dielectric layer with a refractive index different from that of the dielectric layer D2 because the whole film stack is formed by stacking dielectric materials. When two medium layers with different refractive indexes are combined together, the optical thickness of the medium layers can be matched with the admittance of the medium layer D2 on the upper layer by adjusting the thickness of the medium layers or changing the material in the film layers, and the peak half-width and the peak value of the spectrum can be changed from the perspective of spectrum, so that the color is regulated and controlled, the color changing capability of the traditional F-P cavity structure color structure is improved, and the color realization of a higher color gamut range is achieved.

The utility model provides a novel structural color film structure constructed by metal media, which can further greatly improve the overall reflectivity of the film on the basis of the limit reflectivity which can be achieved by the traditional structural color film, and can widen the possibility of selecting materials for improving the brightness of the reflective color of the structural color of the film and selecting materials of a metal layer. The color design range of the structural color film can be increased by using a plurality of different materials for matching, more materials can be provided for matching and combining, and finally the structural color film with red, green, blue and other colors can be designed. The symmetrical structure of the utility model can be used for preparing a film coating, and the film coating can be applied to the surfaces of various optical devices or devices with special optical performance requirements by using a spraying method. The film system with the asymmetric structure design can be directly deposited in an application scene requiring optical structural colors, and the film deposited in the mode has a tighter adhesion degree with a deposition substrate compared with a sprayed film coating. Compared with the prior structure, the film designed by the structure of the utility model can be applied to the surface of military weapons, on one hand, the color adjustment range can be widened to enable the surface color to reach the saturation requirement matched with the environment color, and on the other hand, the brightness of the whole reflection color can be improved to enable the surface color to be more vivid.

One of the embodiments

As shown in FIG. 2, the structural color film consists of a substrate Sub, a metal layer M (Ni) on the substrate, a reflection enhancement film stack D1 (MgF ₂/ZnS), a dielectric layer D2 (MgF ₂) and an absorption layer A (Cr), wherein the substrate adopts a K9 glass deposition film with the diameter of 80 mm, the thickness of 2 mm and the surface quality of 20/10. The specific thicknesses of each of the layers are given in Table 1, and the reflection enhancing film stack D1 in this film system is stacked only once, wherein the high and low refractive index layers of the composition are indicated by H, L, respectively. An asymmetric metallic dielectric-reinforced structural color film system can be prepared according to the thickness values given in table 1. Fig. 3 is a reflection spectrum at normal incidence of example 1 and a reflection spectrum corresponding to a structure without using a reflection enhancement film stack, and fig. 4 is a chromaticity diagram at normal incidence of example 1. By contrast, an asymmetric F-P structure is shown without the reflection enhancement film stack D1, which consists of a substrate Sub, a metal layer M (Ni) on the substrate, a dielectric layer D2 (MgF ₂), and an absorption layer A (Cr), the thickness of which is the same as that of the corresponding film material of Table 1, namely

As can be seen from FIG. 3, the reflectivity of the film system can reach 86%, the peak reflectivity of the film system without the reflection enhancement film stack can only reach 70%, and the reflectivity of the film is improved by 16% by introducing the reflection enhancement film stack. As can be seen from fig. 4, the chromaticity coordinates of the film system are x=0.4745 and y=0.468, the color purity reaches 0.8214, and the film system is orange-yellow and is closer to the edge of the chromaticity trace, showing that the higher the color saturation thereof.

Table 1A film thickness parameter Table (unit: nm) of examples

Examples	Substrate	Layer1 M	Layer2 L	Layer3 H	Layer4 D2	Layer5 A
							1	Glass	66	90	52	224	4

Second embodiment

As shown in FIG. 2, the structural color film consists of a substrate Sub, a metal layer M (Ni) on the substrate, an enhanced reflection layer D1 (MgF ₂/ZnS), a dielectric layer D2 (MgF 2) and an absorption layer A (Cr), wherein the substrate is a K9 glass deposition film with the diameter of 80 mm, the thickness of 2 mm and the surface quality of 20/10. The specific thicknesses of each layer are given in Table 2, and the enhanced reflective layer D1 in the film system is stacked twice, wherein the high and low refractive index layers of the composition are respectively denoted by H, L, and the stacking of the enhanced film stack twice achieves higher peak reflectivity. An asymmetric metallic dielectric-reinforced structural color film system can be prepared according to the thickness values given in table 2. Fig. 5 is a reflection spectrum at normal incidence for example 2, and fig. 6 is a chromaticity diagram at normal incidence for example 2. As can be seen from fig. 5, the reflectivity of the film system can reach 93%, the stacking period of only adding one dielectric enhancement layer is increased by 7 percentage points on the basis of example 1, and the peak full width at half maximum is greatly narrowed, so that the enhancement effect is obvious. Meanwhile, as can be seen from fig. 6, the chromaticity coordinates of the film system are x=0.4457, y= 0.4833, and the color purity reaches 0.8478, and the film system is yellow.

Table 2 two film thickness parameter tables (units: nm) for the examples

Third embodiment

As shown in FIG. 2, the structural color film consists of a substrate Sub, a metal layer M (Cr) on the substrate, an enhanced reflection layer D1 (MgF ₂/ZnS), a medium layer D2 (MgF ₂) and an absorption layer A (Cr), wherein the substrate adopts a K9 glass deposition film with the diameter of 80 mm, the thickness of 2 mm and the surface quality of 20/10. The specific thickness of each layer is given in Table 3, and the enhanced reflection layer D1 in the film system is once stacked, wherein the high and low refractive index layers of the composition are denoted by H, L, respectively. An asymmetric metallic dielectric-reinforced structural color film system can be prepared according to the thickness values given in table 1. Fig. 7 is a reflection spectrum at normal incidence for example 3, and fig. 8 is a chromaticity diagram at normal incidence for example 3. As can be seen from fig. 7, the reflectivity of the film system can reach 79.5%. As can be seen from fig. 8, the chromaticity coordinates of the film system were x=0.4508, y=0.296, and the color purity was 0.326, which represented pink.

Table 3 three film thickness parameter tables (units: nm) for examples

Examples	Substrate	Layer1 M	Layer2 L	Layer3 H	Layer4 D2	Layer5 A
							2	Glass	66	90	52	263	4

Fourth embodiment

As shown in FIG. 2, the structural color film consists of a substrate Sub, a metal layer M (Al) on the substrate, an enhanced reflection layer D1 (MgF ₂/ZnS), a medium layer D2 (MgF ₂) and an absorption layer A (Cr), wherein the substrate adopts a K9 glass deposition film with the diameter of 80 mm, the thickness of 2 mm and the surface quality of 20/10. The specific thickness of each layer is given in Table 4, and the enhanced reflective layer D1 in this film system is stacked only once, wherein the high and low refractive index layers of the composition are indicated by H, L, respectively. An asymmetric metallic dielectric-reinforced structural color film system can be prepared according to the thickness values given in table 1. Fig. 9 is a reflection spectrum at normal incidence for example 1, and fig. 10 is a chromaticity diagram at normal incidence for example 1. As can be seen from FIG. 9, the reflectivity of the film system can reach about 96.6%, and the main reflection wavelength is located at 530nm of the green band. As can be seen from fig. 10, the chromaticity coordinates of the film system are x=0.2522, y= 0.5512, the color purity is 0.6947, and the reflection color is emerald.

Table 4 four film thickness parameter tables (units: nm) for the examples

Examples	Substrate	Layer1 M	Layer2 L	Layer3 H	Layer4 D2	Layer5 A
							4	Glass	66	85	53	360	5

Fifth embodiment of the invention

As shown in FIG. 1, the structural color film comprises a substrate Sub, an absorption layer A (Ti), a dielectric layer D2 (MgF ₂), a reinforced reflection layer D1 (ZnS/MgF ₂), a metal layer M (Ti), a reinforced reflection layer D1 (MgF ₂/ZnS), a dielectric layer D2 (MgF ₂) and an absorption layer A (Ti) on the substrate, wherein the structural color film is symmetrically distributed on two sides relative to a central metal layer M, the distribution materials and the thickness are the same, and the substrate adopts a K9 glass deposition film with the diameter of 80 mm, the thickness of 2 mm and the surface quality of 20/10. The specific thickness of each layer is given in Table 5, and the enhanced reflective layer D1 in this film system is stacked only once, wherein the high and low refractive index layers of the composition are indicated by H, L, respectively. A symmetrical metallic dielectric reinforced structural color film system can be prepared according to the thickness values given in Table 5. Fig. 11 is a reflection spectrum at normal incidence of example 5 and a reflection spectrum corresponding to a structure without using a reflection enhancement film stack, and fig. 12 is a chromaticity diagram at normal incidence of example 5. By contrast, a symmetrical F-P structure without the reflection enhancement film stack D1 is given, the structure is composed of a substrate Sub, an absorption layer A (Ti), a dielectric layer D2 (MgF ₂), a metal layer M (Ti), a dielectric layer D2 (MgF ₂) and an absorption layer A (Ti), which are symmetrically distributed on both sides relative to the central metal layer M, and the distribution materials and the thickness are the same, namely, sub/A (6 nm)/D2 (329 nm) M (66 nm)/D2 (329 nm)/A (6 nm), and as can be seen from FIG. 11, the reflectivity of the film system can reach 76.8%, the peak reflectivity without the reflection enhancement film stack is only 55%, and the reflectivity of the film is improved by 21.8% through the introduction of the reflection enhancement film stack. As can be seen from fig. 12, the chromaticity coordinates of the film system were x=0.178 and y=0.182, and the color purity reached 0.3317, indicating that the reflection color was blue. The film system uses relatively environment-friendly metal Ti, and the symmetrical environment-friendly film can be used as a coating to be applied to the field of industrial device coating.

Table 5 five film thickness parameter tables (units: nm) for the examples

According to the embodiment, the utility model provides a novel structural color film structure constructed by metal media, and the structure can further greatly improve the overall reflectivity of the film on the basis of the limit reflectivity which can be achieved by the traditional structural color film, so that the possibility of material selection is widened for improving the brightness of the reflective color of the structural color of the film and selecting the material of the metal layer. The color design range of the structural color film can be increased by using a plurality of different materials for matching, more materials can be provided for matching and combining, and finally the structural color film with red, green, blue and other colors can be designed. The structure made by the symmetrical structure of the utility model can be made into a film coating, and the film coating can be applied to the surfaces of various optical devices or devices with special optical performance requirements by using a spraying method. The film system with the asymmetric structure design can be directly deposited in an application scene requiring optical structural colors, and the film deposited in the mode has a tighter adhesion degree with a deposition substrate compared with a sprayed film coating. Compared with the prior structure, the film designed by the structure of the utility model can be applied to the surface of military weapons, on one hand, the color adjustment range can be widened to enable the surface color to reach the saturation requirement matched with the environment color, and on the other hand, the brightness of the whole reflection color can be improved to enable the surface color to be more vivid.

Sixth embodiment

An F-P resonant cavity comprises the enhanced reflection type metal dielectric structural color film. The advantages of this film are described above and will not be described in detail here.

The foregoing description is only a partial embodiment of the present utility model, and is not intended to limit the scope of the present utility model, and all equivalent devices or equivalent processes using the descriptions and the drawings of the present utility model or directly or indirectly applied to other related technical fields are included in the scope of the present utility model.

Claims

1. The structural color film is used for an F-P cavity structure and is characterized by comprising a dielectric layer and a metal layer;

An enhanced reflection layer is arranged between the dielectric layer and the metal layer;

2. An enhanced reflective metal dielectric structured color film as recited in claim 1, wherein,

The low refractive index dielectric film in the enhancement film stack is closer to the metal layer than the high refractive index dielectric film.

3. An enhanced reflective metal dielectric structured color film as recited in claim 1, wherein,

The high refractive index dielectric film is a material with the refractive index of 1.7-3 and the wavelength of 380 nm-780 nm.

4. An enhanced reflective metal dielectric structured color film as recited in claim 1, wherein,

The low refractive index dielectric film is a material with the wavelength of 380 nm-780 nm and the refractive index of 1.2-1.70.

5. An enhanced reflective metal dielectric structured color film as recited in claim 1, wherein,

The dielectric layer is a material with the wavelength of 380-780 nm and the refractive index of 1.2-3.0, and the thickness of the dielectric layer is 50-1000 nm.

6. An enhanced reflective metal dielectric structured color film as recited in claim 1, wherein,

The thickness of the metal layer is between 20nm and 200 nm.

7. An enhanced reflective metal dielectric structured color film as recited in claim 1, wherein,

The structural color film also comprises an absorption layer which is arranged on one side of the dielectric layer far away from the enhanced reflection layer, is made of metal simple substance and mixture thereof or semiconductor material with absorption characteristic, and has the thickness of 3nm-30 nm.

8. An F-P resonator comprising an enhanced reflective metallic dielectric structural color film as defined in any one of claims 1-7.