Structural color multilayer structure with barrier layer

Abstract

The color reflecting multilayer structure has a core layer and a conformal dielectric layer covering the core layer. The conformal barrier layer encapsulates the conformal dielectric layer, and the conformal absorber layer encapsulates the conformal barrier layer.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of priority under 35 U.S.C. §119 to U.S. Provisional Application Serial No. 63 / 404,413, filed on September 7, 2022, the contents of which are referenced and incorporated herein by reference in their entirety. Technical Field

[0003] The present application relates to a multilayer structure, and in particular, to a multilayer structure for optical applications, comprising a multilayer structure comprising a metal and a metal oxide over a substrate, at least one of the metal and the metal oxide being deposited by atomic layer deposition (ALD), and a barrier layer being disposed between each adjacent metal layer and / or metal oxide layer. Background Art

[0004] Pigments made from multilayer structures are known. In addition, pigments that exhibit or provide high chromaticity structural colors are also known. However, forming multilayer structures from certain materials can be difficult because the deposition techniques used to deposit the various materials can have a negative impact on previously deposited materials. In addition, certain deposition techniques can be costly and time consuming, which makes it difficult to achieve commercially viable multilayer structures.

[0005] It should be understood that the color produced by a multilayer structure depends on the materials used as the various layers, the position of the materials within the multilayer structure, and the properties of the various layers (e.g., thickness). Therefore, small changes in the design of the multilayer structure may have a significant impact on the color produced by the multilayer structure. However, conventional deposition techniques are not always effective for depositing the desired layers within the multilayer structure to achieve the optimal combination of the multilayer structure. Summary of the invention

[0006] According to an embodiment, a multi-layer structure that reflects color includes: a core layer; a conformal dielectric layer encapsulating the core layer; a conformal barrier layer encapsulating the conformal dielectric layer; and a conformal absorbing layer encapsulating the conformal barrier layer.

[0007] According to an embodiment, the multilayer structure further comprises: a second conformal barrier layer encapsulating the conformal absorber layer; and a second conformal dielectric layer encapsulating the second conformal barrier layer.

[0008] According to an embodiment, a method for fabricating a multilayer structure includes: depositing a conformal dielectric layer onto a core layer by CVD or ALD; depositing a conformal barrier layer onto the conformal dielectric layer by ALD; and depositing a conformal absorber layer onto the conformal dielectric layer by ALD.

[0009] Additional features and advantages will be set forth in the following detailed description, and in part will be readily apparent to those skilled in the art from this description or recognized by practicing the embodiments described herein, including the following detailed description, claims, and accompanying drawings.

[0010] It should be understood that both the foregoing general description and the following detailed description describe various embodiments and are intended to provide an overview or framework for understanding the nature and character of the claimed subject matter. The accompanying drawings are included to provide a further understanding of the various embodiments and are incorporated into and constitute a part of this specification. The accompanying drawings illustrate various embodiments described herein and together with the description serve to explain the principles and operation of the claimed subject matter. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 schematically depicts a multi-layer structure according to embodiments disclosed and described herein;

[0012] Figure 2A depicts a multilayer structure in which a dielectric layer used in the design of a multilayer structure extends over a reflective core layer;

[0013] Figure 2B depicts a multilayer structure in which an absorber layer extends over a reflective core layer for use in the design of a multilayer structure;

[0014] Figure 2C depicts a multilayer structure in which a dielectric layer extends over a reflective core layer for use in the design of a multilayer structure in accordance with one or more embodiments shown and described herein;

[0015] Figure 3 Depicted FIG. 2A to FIG. 2C Reflectance properties of the multilayer structure shown in the Lab color space;

[0016] Figure 4A Graphically depicts the Figure 2A Chromaticity and hue values ​​of dielectric layer thickness of the multilayer structure shown in ;

[0017] Figure 4B Graphically depicts the Figure 2B Chromaticity and hue values ​​of the semiconductor absorber layer thickness of the multilayer structure shown in ;

[0018] Figure 4C Graphically depicts the Figure 2C Chromaticity and hue values ​​of dielectric layer thickness of the multilayer structure shown in ;

[0019] Figure 5depicts a multilayer structure wherein a dielectric layer extends over a substrate layer and is exposed to electromagnetic radiation at an angle θ relative to a normal direction to an outer surface of the dielectric layer;

[0020] Fig. 6A is a transmission electron microscope (TEM) image of a multilayer structure having a protective layer and a barrier layer according to an embodiment disclosed and described herein;

[0021] Figure 6B is a further magnified TEM image of a multilayer structure having a protective layer and a barrier layer according to an embodiment disclosed and described herein;

[0022] Figure 6C is a TEM image of a multilayer structure having a protective layer and a barrier layer according to an embodiment disclosed and described herein, wherein the element aluminum is highlighted;

[0023] Fig.6D is a TEM image of a multilayer structure having a protective layer and a barrier layer according to an embodiment disclosed and described herein, wherein elemental oxygen is highlighted;

[0024] Fig. 6E is a TEM image of a multilayer structure having a protective layer and a barrier layer according to an embodiment disclosed and described herein, wherein the element tungsten is highlighted;

[0025] Fig. 6F is a TEM image of a multilayer structure having a protective layer and a barrier layer according to an embodiment disclosed and described herein, wherein elemental titanium is highlighted;

[0026] Fig. 7A is a TEM image of a multilayer structure without a barrier layer;

[0027] Figure 7B is a further magnified TEM image of the multilayer structure without the barrier layer;

[0028] Figure 7C is a TEM image of a multilayer structure without a barrier layer, wherein the element aluminum is highlighted;

[0029] Fig.7D is a TEM image of a multilayer structure without a barrier layer, in which elemental oxygen is highlighted;

[0030] Fig. 7E is a TEM image of a multilayer structure without a barrier layer, wherein element tungsten is highlighted; and

[0031] Figure 7F is a TEM image of a multilayer structure without a barrier layer, in which the element titanium is highlighted. DETAILED DESCRIPTION

[0032] Preparing multilayer structures can be a complex, expensive process, in part because very tight control over layer thickness is required. The deposition methods used to deposit the layers can vary in complexity and cost depending on the materials making up a given layer and the desired layer thickness.

[0033] Furthermore, it can be challenging to deposit layers directly onto a core layer (such as an aluminum (Al) reflective core layer) by less expensive wet chemical methods, as these methods require highly acidic or alkaline conditions. Furthermore, in addition to challenges with vacuum coating methods, there are challenges with depositing precisely controlled ultra-thin absorber layers. For example, ALD can precisely deposit thin layers, but ALD is costly and time consuming. In particular, conventionally used ALD methods are small batch and too expensive to manufacture on a commercial scale. Furthermore, when attempting to increase production volume, it is noted that various metal layers and / or metal oxide layers overlap each other and form mixed layers, which may have an impact on the optical properties of the multilayer structure.

[0034] Embodiments of the multilayer structures described herein can be used to omnidirectionally reflect visible light wavelengths within a range of incident or viewing angles (such as, hues between 0° and 120°). It should be understood that the terms "electromagnetic wave," "electromagnetic radiation," and "light" as used herein can refer interchangeably to various wavelengths of light incident on the multilayer structure, and it should be understood that such light can have wavelengths in the ultraviolet (UV), infrared (IR), and visible portions of the electromagnetic spectrum.

[0035] As used herein, "core layer" refers to a reflective core layer and a non-reflective core layer, and the "core layer" may have any shape, including but not limited to sheet, sphere, oval, etc. As used herein, "absorption layer" includes metal absorption layer and non-metal absorption layer.

[0036] Now refer to Figure 1 The multilayer structure 100 according to the embodiments disclosed and described herein includes: a core layer 110; a first conformal protective layer 111 coating the core layer 110; a conformal dielectric layer 120 coating the first conformal protective layer 111; a conformal barrier layer 121 coating the conformal dielectric layer 120; a conformal absorber layer 130 coating the conformal barrier layer 121; a second conformal barrier layer 131 coating the conformal absorber layer 130; a second conformal dielectric layer 140 coating the second conformal barrier layer 131; and a conformal outer layer 141 coating the second conformal dielectric layer 140.

[0037] In one or more embodiments, the multilayer structure 100 may include Figure 1For example, in an embodiment, multilayer structure 100 includes: core layer 110; first conformal protective layer 111 encapsulating core layer 110; conformal dielectric layer 120 encapsulating first conformal protective layer 111; conformal barrier layer 121 encapsulating conformal dielectric layer 120; conformal absorber layer 130 encapsulating conformal barrier layer 121; second conformal barrier layer 131 encapsulating conformal absorber layer 130; and second conformal dielectric layer 140 encapsulating second conformal barrier layer 131.

[0038] In one or more embodiments, multilayer structure 100 includes: core layer 110; conformal dielectric layer 120 encapsulating core layer 110; conformal barrier layer 121 encapsulating conformal dielectric layer 120; conformal absorber layer 130 encapsulating conformal barrier layer 121; second conformal barrier layer 131 encapsulating conformal absorber layer 130; and second conformal dielectric layer 140 encapsulating second conformal barrier layer 131. An optional conformal outer layer 141 may encapsulate second conformal dielectric layer 140.

[0039] In an embodiment, multilayer structure 100 includes: core layer 110; conformal dielectric layer 120 coating core layer 110; conformal barrier layer 121 coating conformal dielectric layer 120; and conformal absorber layer 130 coating conformal barrier layer 121. A protective layer may optionally coat the conformal absorber layer.

[0040] In one or more embodiments, the multilayer structure 100 includes: a core layer 110; a first conformal protective layer 111 covering the core layer 110; a conformal dielectric layer 120 covering the first conformal protective layer 111; a conformal barrier layer 121 covering the conformal dielectric layer 120; and a conformal absorber layer 130 covering the conformal barrier layer 121. The second conformal barrier layer 131 may optionally cover the conformal absorber layer 130.

[0041] Reference FIG. 2A to FIG. 2C and Figure 3 , depicting the effectiveness of different types of layers extending across the reflective core layer 110 in achieving a desired hue level in the red region of the visible light spectrum as plotted or illustrated on Lab color space. Figure 2A A ZnS dielectric layer 120a extending across the reflective core layer 110 is depicted, Figure 2B depicts a Si semiconductor absorber layer 120b extending across the reflective core layer 110, and Figure 2C The Fe2O3 absorption layer 120c is depicted extending across the reflective core layer 110. The different thicknesses of the dielectric layer 120a, the semiconductor absorption layer 120b, and the absorption layer 120c are implemented FIG. 2A to FIG. 2C Simulation of the reflectivity of each multilayer structure shown in Figure 3 As shown in , the results of the simulation are plotted on the Lab color space, also known as the a*b* color diagram. Figure 3 Each data point shown in Figure 2A The dielectric layer of the multilayer structure depicted in Figure 2B The semiconductor absorption layer of the multilayer structure depicted in FIG. Figure 2C The chromaticity and hue of a particular thickness of the absorber layer of the multilayer structure depicted in FIG. Chromaticity can be defined as And the hue can be defined as tan -1 (a* / b*). Hue can also be referred to as the angle relative to the positive a* axis for a given data point. Hue values ​​provide a measure of the color (e.g., red, green, blue, yellow, etc.) displayed by an object, and chromaticity values ​​provide a measure of the "brightness" of the color. Figure 3 As shown in Figure 2A The multilayer structure shown in Figure 2B and Figure 2C The multilayer structure shown in FIG. 1 provides low chromaticity compared to the multilayer structure shown in FIG. FIG. 2A to FIG. 2C and Figure 3 It is demonstrated that when a color with high chromaticity is desired, an absorbing layer (eg, an absorbing layer) is preferably on a dielectric layer as the first layer extending above a reflective core layer. It should be understood that Figure 3 The Lab color space analysis shown in is for illustrative purposes, and it should be understood that the multilayer structure according to the embodiments disclosed and described herein can have different Lab color space values. For example, in an embodiment, the multilayer structure can present blue, green, yellow or other colors in the Lab color space.

[0042] Reference FIG. 4A to FIG. 4C , depicting the chroma and hue according to layer thickness. Specifically, Figure 4A Graphically depicts the Figure 2A Chroma and hue of the thickness of the ZnS dielectric layer extending over the Al reflective core layer shown in FIG. Figure 4B Describes the basis Figure 2B Chroma and hue of the thickness of the Si semiconductor absorber layer extending over the Al reflective core layer shown in FIG. Figure 4C Describes the basis Figure 2C Chroma and hue of the thickness of the Fe2O3 absorber layer extending over the Al reflective core layer shown in FIG. FIG. 4A to FIG. 4C The dashed line in corresponds to the desired hue value between 10° and 30° on the Lab color space. FIG. 4A to FIG. 4C It is shown that higher chromaticity values ​​in the hue range between 10° and 30° are achieved for a multilayer structure having an absorber layer extending across a reflective core layer. In addition, it should be understood that FIG. 4A to FIG. 4C The hues and chromas shown in are for illustrative purposes, and it is understood that multi-layer structures according to embodiments disclosed and described herein may have different hue and chroma values.

[0043] Refer again Figure 1 , the multilayer structure 100 includes: a core layer 110; a first conformal protective layer 111 coating the core layer 110; a conformal dielectric layer 120 coating the first conformal protective layer 111; a first conformal barrier layer 121 coating the conformal dielectric layer 120; a conformal absorber layer 130 coating the first conformal barrier layer 121; a second conformal barrier layer 131 coating the conformal absorber layer 130; a second conformal dielectric layer 140 coating the second conformal barrier layer 131; and an optional conformal outer layer 141 coating the second conformal dielectric layer 140. In an embodiment, the "outer layer" has an outer free surface (i.e., an outer surface that is not in contact with the absorber layer or another dielectric layer that is not part of the protective coating). Figure 1 As shown in , embodiments of the multilayer structures disclosed and described herein include a conformal dielectric layer 120 and a conformal absorber layer 130. As used herein, "conformal" is used to indicate that a layer conforms to the size and shape of the layer onto which it is deposited and wraps around (i.e., is present on all sides) the size and shape of the layer onto which it is deposited, as well as conforming to the contours of the layer onto which it is deposited. Although Figure 1 A rectangular structure is shown, but this is for illustration purposes only, and typically the multilayer structure has an asymmetric and non-uniform shape. In embodiments, the multilayer structure may be spherical or oval. It should be understood that embodiments may also include a multilayer structure having a conformal absorber layer encapsulating a core layer and a conformal dielectric layer encapsulating the conformal absorber layer.

[0044] In an embodiment, the core layer 110 may have a thickness greater than or equal to 20 nm and less than or equal to 100 μm, such as greater than or equal to 50 nm and less than or equal to 80 μm, greater than or equal to 75 nm and less than or equal to 60 μm, greater than or equal to 100 nm and less than or equal to 40 μm, greater than or equal to 125 nm and less than or equal to 20 μm, or greater than or equal to 150 nm and less than or equal to 1 μm. In one or more embodiments, the core layer 110 may have a diameter between 50 nm and 10 μm, such as between 100 nm and 10 μm, between 250 nm and 10 μm, between 500 nm and 10 μm, between 750 nm and 10 μm, between 1 μm and 10 μm, between 2 μm and 10 μm, between 5 μm and 10 μm, between 8 μm and 10 μm, between 50 nm and 8 μm, between 100 nm and 8 μm, between 250 nm and 8 μm, between 500 nm and 8 μm, between 750 nm and 8 μm, between 1 μm and 8 μm, between 2 μm and 8 μm, between 5 μm and 8 μm, between 50 nm and 5 μm, between 100 nm and 5 μm, between 250 nm and 5 μm, between 500 nm and 5 μm, between 750 nm and 5 μm, between 1 μm and 10 μm, between 2 μm and 10 μm, between 5 μm and 10 μm, between 5 or a thickness of between 5 μm, between 2 μm and 5 μm, between 50 nm and 2 μm, between 100 nm and 2 μm, between 250 nm and 2 μm, between 500 nm and 2 μm, between 750 nm and 2 μm, between 1 μm and 2 μm, between 50 nm and 1 μm, between 100 nm and 1 μm, between 250 nm and 1 μm, between 500 nm and 1 μm, between 750 nm and 1 μm, between 50 nm and 750 nm, between 100 nm and 750 nm, between 250 nm and 750 nm, between 500 nm and 750 nm, between 50 nm and 500 nm, between 100 nm and 500 nm, between 250 nm and 500 nm, between 50 nm and 250 nm, between 100 nm and 250 nm, or between 50 nm and 100 nm.

[0045] In an embodiment, the core layer 110 may be made of at least one of "gray metal" materials such as Al, Ag, Pt, Sn; at least one of "colored metal" materials such as Au, Cu, brass, bronze, TiN, Cr, stainless steel, or a combination thereof. In one or more embodiments, the core layer 110 may be made of an oxide such as aluminum oxide (Al2O3), silicon dioxide (SiO2), bismuth oxychloride, or a glass material. As mentioned above, the core layer 110 may have a plate-like shape or may be spherical or oval.

[0046] In one or more embodiments, the first conformal protective layer 111 has a thickness of less than or equal to 50 nm and greater than or equal to 5 nm, such as less than or equal to 40 nm and greater than or equal to 5 nm, less than or equal to 30 nm and greater than or equal to 5 nm, less than or equal to 20 nm and greater than or equal to 5 nm, less than or equal to 10 nm and greater than or equal to 5 nm, less than or equal to 50 nm and greater than or equal to 10 nm, less than or equal to 40 nm and greater than or equal to 10 nm, less than or equal to 30 nm and greater than or equal to 10 nm, less than or equal to 20 nm and greater than or equal to 10 nm, less than or equal to 50 nm and greater than or equal to 20 nm, less than or equal to 40 nm and greater than or equal to 20 nm, less than or equal to 30 nm and greater than or equal to 20 nm, less than or equal to 50 nm and greater than or equal to 30 nm, less than or equal to 40 nm and greater than or equal to 30 nm, or less than or equal to 50 nm and greater than or equal to 40 nm.

[0047] In an embodiment, the first conformal protective layer 111 may be formed of a chromate coating, a phosphate coating, an oxide coating (such as SiO 2 ), and may be applied to the core layer 110 by chemical vapor deposition (CVD), physical vapor deposition (PVD), a wet chemical method, or ALD.

[0048] According to one or more embodiments, the conformal dielectric layer 120 has a thickness greater than or equal to 5 nm and less than or equal to 500 nm, such as greater than or equal to 10 nm and less than or equal to 475 nm, greater than or equal to 10 nm and less than or equal to 450 nm, greater than or equal to 10 nm and less than or equal to 425 nm, greater than or equal to 10 nm and less than or equal to 400 nm, greater than or equal to 10 nm and less than or equal to 375 nm, greater than or equal to 10 nm and less than or equal to 350 nm, greater than or equal to 10 nm and less than or equal to 325 nm, or greater than or equal to 10 nm and less than or equal to 300 nm. According to an embodiment, the conformal dielectric layer 120 may have a thickness between 5 nm and 300 nm, such as between 10 nm and 300 nm, between 15 nm and 300 nm, between 25 nm and 300 nm, between 50 nm and 300 nm, between 75 nm and 300 nm, between 100 nm and 300 nm, between 125 nm and 300 nm, between 150 nm and 300 nm, between 175 nm and 300 nm, between 200 nm and 300 nm, between 225 nm and 300 nm, between 250 nm and 300 nm, and between 300 nm and 300 nm. nm, between 275nm and 300nm, between 5nm and 275nm, between 10nm and 275nm, between 15nm and 275nm, between 25nm and 275nm, between 50nm and 275nm, between 75nm and 275nm, between 100nm and 275nm, between 125nm and 275nm, between 150nm and 275nm, between 175nm and 275nm, between 200nm and 275nm, between 225nm and 275nm, between 250nm and 275nm , between 5nm and 250nm, between 10nm and 250nm, between 15nm and 250nm, between 25nm and 250nm, between 50nm and 250nm, between 75nm and 250nm, between 100nm and 250nm, between 125nm and 250nm, between 150nm and 250nm, between 175nm and 250nm, between 200nm and 250nm, between 225nm and 250nm, between 5nm and 225nm, between 10nm and 225nm, between 15nm and 2 Between 25nm, Between 25nm and 225nm, Between 50nm and 225nm, Between 75nm and 225nm, Between 100nm and 225nm, Between 125nm and 225nm, Between 150nm and 225nm, Between 175nm and 225nm, Between 200nm and 225nm, Between 5nm and 200nm, Between 10nm and 200nm, Between 15nm and 200nm, Between 25nm and 200nm, Between 50nm and 200nm, Between 75nm and 200nm,Between 100nm and 200nm, between 125nm and 200nm, between 150nm and 200nm, between 175nm and 200nm, between 5nm and 175nm, between 10nm and 175nm, between 15nm and 175nm, between 25nm and 175nm, between 50nm and 175nm, between 75nm and 175nm, between 100nm and 175nm, between 125nm and 175nm, between 150nm and 175nm, between 5nm and 150nm, between 10nm and 150nm, between 15nm and 150nm, between 25nm and 150nm, between 50nm and 150nm, between 75nm and 150nm, between 100nm and 150nm, between 125nm and 175nm or a thickness between 5nm and 150nm, between 5nm and 100nm, between 10nm and 100nm, between 15nm and 100nm, between 25nm and 100nm, between 50nm and 100nm, between 75nm and 100nm, between 5nm and 75nm, between 10nm and 75nm, between 15nm and 75nm, between 25nm and 75nm, between 50nm and 75nm, between 5nm and 50nm, between 10nm and 50nm, between 15nm and 50nm, between 25nm and 50nm, between 5nm and 25nm, between 10nm and 25nm, between 15nm and 25nm, between 5nm and 15nm, between 10nm and 15nm, or between 5nm and 10nm.

[0049] In an embodiment, the first conformal dielectric layer 120 is a high refractive index material such as TiO2 (including anatase, rutile or amorphous TiO2 and mixtures thereof), ZnS, ZrO2, HfO2, Fe3O4 or AlAs. In one or more embodiments, the conformal dielectric layer 120 may be made of a high refractive index absorbing dielectric material such as Fe2O3, PbS, GaAs or InAs. In an embodiment, the conformal dielectric layer may be made of a low refractive index material such as SiO2, MgF2, KBr, ZnO or Al2O3. In an embodiment, the conformal dielectric layer 120 may be deposited by CVD, PVD, wet chemical methods or ALD to coat the core layer 110.

[0050] In an embodiment, the first conformal barrier layer 121 has a thickness less than or equal to 50 nm, such as less than or equal to 45 nm, less than or equal to 40 nm, less than or equal to 35 nm, less than or equal to 30 nm, less than or equal to 25 nm, less than or equal to 20 nm, such as less than or equal to 15 nm, less than or equal to 10 nm, less than or equal to 5 nm, or less than or equal to 2 nm. According to an embodiment, the barrier layer has a thickness greater than or equal to 1 nm and less than or equal to 50 nm, such as greater than or equal to 1 nm and less than or equal to 45 nm, greater than or equal to 1 nm and less than or equal to 40 nm, greater than or equal to 1 nm and less than or equal to 35 nm, greater than or equal to 1 nm and less than or equal to 30 nm, or greater than or equal to 1 nm and less than or equal to 25 nm. In one or more embodiments, the blocking layer has a thickness greater than or equal to 1 nm and less than or equal to 20 nm, such as greater than or equal to 1 nm and less than or equal to 15 nm, greater than or equal to 1 nm and less than or equal to 10 nm, greater than or equal to 1 nm and less than or equal to 5 nm, greater than or equal to 1 nm and less than or equal to 2 nm, greater than or equal to 2 nm and less than or equal to 20 nm, greater than or equal to 2 nm and less than or equal to 15 nm, greater than or equal to 2 nm and less than or equal to 10 nm, greater than or equal to 2 nm and less than or equal to 5 nm, greater than or equal to 5 nm and less than or equal to 20 nm, greater than or equal to 5 nm and less than or equal to 15 nm, greater than or equal to 5 nm and less than or equal to 10 nm, greater than or equal to 10 nm and less than or equal to 20 nm, greater than or equal to 10 nm and less than or equal to 20 nm, greater than or equal to 15 nm and less than or equal to 20 nm, or greater than or equal to 15 nm and less than or equal to 20 nm.

[0051] In an embodiment, the first conformal barrier layer 121 may be formed of Al 2 O 3 , SiO 2 , MgF 2 , KBr, or ZnO, and may be applied to the first conformal dielectric layer 120 by ALD.

[0052] The conformal absorber layer 130 encapsulates the first conformal barrier layer 121. The location of the conformal absorber layer 130 is selected to increase absorption of the target wavelength of light. For example, if the multilayer structure is to be configured to absorb electromagnetic radiation having a wavelength less than or equal to 550 nm, but reflect electromagnetic radiation having a wavelength of approximately 650 nm, such as visible light outside the hue between 10° and 30°, then the absorber layer is placed at an electric field (|E|) at a wavelength of 550 nm. 2 ) is less than the electric field at a wavelength of 650nm (|E| 2 ) at the thickness of the substrate. Mathematically, this can be expressed as follows:

[0053] E 550 | 2 <<|E650 | 2 (1)

[0054] And preferably:

[0055] |E 650 | 2 ≈0 (2)

[0056] According to an embodiment, Figure 5 and the following discussion provide methods for calculating the thickness of a zero electric field point or near zero electric field point at a given wavelength of light. For the purposes of this specification, the term "near zero" is defined as |E| 2 ≤10. Figure 5 shows that the s The invention relates to a multilayer structure of a dielectric layer 4 having a total thickness "D", an incremental thickness "d" and a refractive index "n" on a substrate layer 2 of ". The substrate layer 2 can be a core layer or a reflective core layer of the multilayer structure. The incident light strikes the outer surface 5 of the dielectric layer 4 at an angle θ relative to a line 6 perpendicular to the outer surface 5 and is reflected from the outer surface 5 at the same angle θ. The incident light is transmitted through the outer surface 5 and is reflected at an angle θ relative to the line 6. F into the dielectric layer 4, and at an angle θ S hits the surface 3 of the substrate layer 2. For a single dielectric layer, θ S =θ F , and the energy / electric field (E) can be expressed as E(z) when z=d. According to Maxwell's equations, the electric field for s-polarization can be expressed as:

[0057]

[0058] and for p-polarization is expressed as:

[0059]

[0060] in, λ is the desired wavelength to be reflected, α = n s sinθ s , where "s" corresponds to the substrate in Figure 7, and is the dielectric constant of the layer according to z, thus:

[0061] For s-polarization,

[0062] |E(d)| 2 =|u(z)| 2 exp(2ikαy)| z＝d (5)

[0063] And for p-polarization,

[0064]

[0065] It will be appreciated that the variation of the electric field along the Z direction of the dielectric layer 4 can be estimated by calculating the unknown parameters u(z) and v(z), where the variation can be shown as:

[0066]

[0067] where 'i' is the square root of -1. Using boundary conditions u| z＝0 =1,v| z＝0 =q s and the following relationship:

[0068] q s =n s cosθ s for s-polarization (8)

[0069] q s =n s / cosθ s for p-polarization (9)

[0070] q=n cosθ F for s-polarization (10)

[0071] q=n / cosθ F for p-polarization (11)

[0072]

[0073] u(z) and v(z) can be expressed as:

[0074]

[0075] as well as

[0076]

[0077] therefore:

[0078] For s-polarization,

[0079]

[0080] in, And for p-polarization:

[0081]

[0082] in:

[0083] α=n s sinθ s = n sinθ F (17)

[0084]

[0085] as well as

[0086]

[0087] Therefore, for θ F = 0 or the simple case of normal incidence, And α=0:

[0088]

[0089] This allows the thickness "d" to be solved for (i.e., the location or position within the dielectric layer where the electric field is zero). It should be understood that the thickness "d" can be the thickness of the first conformal dielectric layer 120, the first conformal barrier layer 121, and the first conformal protective layer 111, which encapsulates the core layer 110 and provides a zero or near-zero electric field at the interface between the first conformal dielectric layer 120 and the conformal absorber layer 130. It should also be understood that the thickness "d" can also be the thickness of the second conformal dielectric layer 140 encapsulating the second conformal barrier layer 131, which provides a zero or near-zero electric field at the interface between the dielectric outer layer and the conformal absorber layer 130 according to the thickness "d" where the electric field is zero or near-zero.

[0090] In an embodiment, the conformal absorber layer has a thickness from greater than or equal to 2 nm and less than or equal to 50 nm, such as greater than or equal to 2 nm and less than or equal to 45 nm, greater than or equal to 2 nm and less than or equal to 40 nm, greater than or equal to 2 nm and less than or equal to 35 nm, greater than or equal to 2 nm and less than or equal to 30 nm, or greater than or equal to 2 nm and less than or equal to 25 nm. In an embodiment, the conformal absorber layer 130 may have a thickness between 2 nm and 20 nm, such as between 5 nm and 20 nm, between 8 nm and 20 nm, between 10 nm and 20 nm, between 12 nm and 20 nm, between 15 nm and 20 nm, between 18 nm and 20 nm, between 2 nm and 18 nm, between 5 nm and 18 nm, between 8 nm and 18 nm, between 10 nm and 18 nm, between 12 nm and 18 nm, between 15 nm and 18 nm , between 2nm and 15nm, between 5nm and 15nm, between 8nm and 15nm, between 10nm and 15nm, between 12nm and 15nm, between 2nm and 12nm, between 5nm and 12nm, between 8nm and 12nm, between 10nm and 12nm, between 2nm and 10nm, between 5nm and 10nm, between 8nm and 10nm, between 2nm and 8nm, between 5nm and 8nm, or between 2nm and 5nm—a thickness between.

[0091] In an embodiment, conformal absorber layer 130 may be made of at least a material selected from W, Cr, Ge, Ni, stainless steel, Pd, Ti, Si, V, TiN, Co, Mo, Nb, iron oxide, or a combination thereof. In one or more embodiments, conformal absorber layer 130 includes W. In an embodiment, ALD is used to deposit conformal absorber layer 130 because ALD allows uniform deposition of materials at a desired thickness. Other deposition methods have difficulty depositing uniform layers at a thickness of 20 nm and below.

[0092] In an embodiment, the second conformal barrier layer 121 has a thickness less than or equal to 50 nm, such as less than or equal to 45 nm, less than or equal to 40 nm, less than or equal to 35 nm, less than or equal to 30 nm, less than or equal to 25 nm, less than or equal to 20 nm, less than or equal to 15 nm, less than or equal to 10 nm, less than or equal to 5 nm, or less than or equal to 2 nm. According to an embodiment, the second conformal barrier layer has a thickness greater than or equal to 1 nm and less than or equal to 50 nm, such as greater than or equal to 1 nm and less than or equal to 45 nm, greater than or equal to 1 nm and less than or equal to 40 nm, greater than or equal to 1 nm and less than or equal to 35 nm, greater than or equal to 1 nm and less than or equal to 30 nm, or greater than or equal to 1 nm and less than or equal to 25 nm. In one or more embodiments, the second conformal barrier layer has a thickness greater than or equal to 1 nm and less than or equal to 20 nm, such as greater than or equal to 1 nm and less than or equal to 15 nm, greater than or equal to 1 nm and less than or equal to 10 nm, greater than or equal to 1 nm and less than or equal to 5 nm, greater than or equal to 1 nm and less than or equal to 2 nm, greater than or equal to 2 nm and less than or equal to 20 nm, greater than or equal to 2 nm and less than or equal to 15 nm, greater than or equal to 2 nm and less than or equal to 10 nm, greater than or equal to 2 nm and less than or equal to 5 nm, greater than or equal to 5 nm and less than or equal to 20 nm, greater than or equal to 5 nm and less than or equal to 15 nm, greater than or equal to 5 nm and less than or equal to 10 nm, greater than or equal to 10 nm and less than or equal to 20 nm, greater than or equal to 10 nm and less than or equal to 20 nm, greater than or equal to 15 nm and less than or equal to 20 nm, or greater than or equal to 15 nm and less than or equal to 20 nm.

[0093] In an embodiment, the second conformal barrier layer 131 may be formed of SiO 2 , MgF 2 , KBr, ZnO, or Al 2 O 3 , and may be applied to the conformal absorber layer 130 by chemical vapor deposition (CVD), physical vapor deposition (PVD), wet chemical methods, or ALD.

[0094] In an embodiment, the second conformal dielectric layer 140 may have a thickness greater than 0.1 quarter wave (QW) to less than or equal to 4.0 QW, such as between 0.5 QW and 4.0 QW, between 1.0 QW and 4.0 QW, between 1.5 QW and 4.0 QW, between 2.0 QW and 4.0 QW, between 2.5 QW and 4.0 QW, between 3.0 QW and 4.0 QW, or between 3.5 QW and 4.0 QW, where the control wavelength is determined by the target wavelength at the peak reflectivity in the visible wavelength. In an embodiment, the second conformal dielectric layer 140 may have a thickness from greater than 0.1 QW to less than 3.5 QW, such as from greater than 0.1 QW to less than 3.0 QW, from greater than 0.1 QW to less than 2.5 QW, from greater than 0.1 QW to less than 2.0 QW, from greater than 0.1 QW to less than 1.5 QW, from greater than 0.1 QW to less than 1.0 QW, or from greater than 0.1 QW to less than 0.5 QW. In some embodiments, the second conformal dielectric layer 140 may have a thickness from 0.5 QW to 3.5 QW, such as from 1.0 QW to 3.0 QW or from 1.5 QW to 2.5 QW. In an embodiment, the target wavelength may be approximately 1050 nm.

[0095] In an embodiment, the second conformal dielectric layer 140 may be formed of TiO2 (including anatase, rutile or amorphous TiO2 and mixtures thereof), ZnS, ZrO2, HfO2, Fe3O4 or AlAs. In one or more embodiments, the second conformal dielectric layer 140 may be made of a high refractive index absorbing dielectric material such as Fe2O3, PbS, GaAs, InAs. In an embodiment, the second conformal dielectric layer 140 may be made of a low refractive index material such as SiO2, MgF2, KBr, ZnO or Al2O3. In an embodiment, the second conformal dielectric layer 140 may be deposited by CVD or ALD.

[0096] In an embodiment, the second conformal dielectric layer 140 may have a thickness between 5 nm and 500 nm, such as between 50 nm and 500 nm, between 100 nm and 500 nm, between 150 nm and 500 nm, between 200 nm and 500 nm, between 250 nm and 500 nm, between 300 nm and 500 nm, between 350 nm and 500 nm, between 400 nm and 500 nm, or between 450 nm and 500 nm. In some embodiments, the second conformal dielectric layer 140 may have a thickness between 5 nm and 450 nm, such as between 5 nm and 400 nm, between 5 nm and 350 nm, between 5 nm and 300 nm, between 5 nm and 250 nm, between 5 nm and 200 nm, between 5 nm and 150 nm, between 5 nm and 100 nm, or between 5 nm and 50 nm. In an implementation, the second conformal dielectric layer 140 may have a thickness between 50 nm and 450 nm, such as between 100 nm and 400 nm, between 150 nm and 350 nm, or between 200 nm and 300 nm.

[0097] According to an embodiment, the conformal outer layer 141 has a thickness of less than or equal to 50 nm and greater than or equal to 5 nm, such as less than or equal to 40 nm and greater than or equal to 5 nm, less than or equal to 30 nm and greater than or equal to 5 nm, less than or equal to 20 nm and greater than or equal to 5 nm, less than or equal to 10 nm and greater than or equal to 5 nm, less than or equal to 50 nm and greater than or equal to 10 nm, less than or equal to 40 nm and greater than or equal to 10 nm, less than or equal to 30 nm and greater than or equal to 10 nm, less than or equal to 20 nm and greater than or equal to 10 nm, less than or equal to 50 nm and greater than or equal to 20 nm, less than or equal to 40 nm and greater than or equal to 20 nm, less than or equal to 30 nm and greater than or equal to 20 nm, less than or equal to 50 nm and greater than or equal to 30 nm, less than or equal to 40 nm and greater than or equal to 30 nm, or less than or equal to 50 nm and greater than or equal to 40 nm.

[0098] In an embodiment, the conformal outer layer 141 may be formed of silicon dioxide (SiO 2 ), MgF 2 , KBr, ZnO, Al 2 O 3 , and may be applied to the conformal absorber layer 130 by CVD, PVD, wet chemical methods, or ALD.

[0099] In one or more embodiments, each of the core layer 110, the first conformal dielectric layer 120, the conformal absorber layer 130, and the second conformal dielectric layer 140 has a thickness less than or equal to 0.030 cm 3 / g——such as less than or equal to 0.025cm 3 / g, less than or equal to 0.020cm 3 / g, or less than or equal to 0.015cm 3 In an embodiment, each of the core layer 110, the first conformal dielectric layer 120, the conformal absorber layer 130, and the second conformal dielectric layer 140 has a pore volume less than or equal to 0.010 cm 3 / g——such as less than or equal to 0.009cm 3 / g, less than or equal to 0.008cm 3 / g, less than or equal to 0.007cm 3 / g, less than or equal to 0.006cm 3 / g, less than or equal to 0.005cm 3 / g pore volume, less than or equal to 0.004cm 3 / g, less than or equal to 0.003cm 3 / g, less than or equal to 0.002cm 3 / g, less than or equal to 0.001cm 3 It should be understood that in an embodiment, one or more of the core layer 110, the first conformal dielectric layer 120, the conformal absorber layer 130, and the second conformal dielectric layer 140 may have the same pore volume, and in other embodiments, one or more of the core layer 110, the first conformal dielectric layer 120, the conformal absorber layer 130, and the second conformal dielectric layer 140 may have different pore volumes.

[0100] In one or more embodiments, the surface area of ​​each of the core layer 110, the first conformal dielectric layer 120, the conformal absorber layer 130, and the second conformal dielectric layer 140 is individually less than or equal to 100 square meters per gram (m2). 2 / g) such as less than or equal to 90m 2 / g, less than or equal to 85m 2 / g, less than or equal to 80m 2 / g, less than or equal to 75m 2 / g, less than or equal to 70m 2 / g, less than or equal to 65m 2 / g, less than or equal to 60m 2 / g, less than or equal to 55m 2 / g, less than or equal to 50m 2 / g, less than or equal to 45m 2 / g, less than or equal to 40m 2 / g, less than or equal to 35m 2 / g, less than or equal to 30m 2 / g, less than or equal to 25m 2 / g, less than or equal to 20m 2 / g or less than or equal to 15m 2 In an embodiment, the surface area of ​​each of the core layer 110, the first conformal dielectric layer 120, the conformal absorber layer 130, and the second conformal dielectric layer 140 is individually less than or equal to 10 m 2 / g such as less than or equal to 9m 2 / g, less than or equal to 8m 2 / g, less than or equal to 7m 2 / g, less than or equal to 6m 2 / g, less than or equal to 5m 2 / g, less than or equal to 4m 2 / g, less than or equal to 3m 2 / g, less than or equal to 2m 2 / g or less than or equal to 1m 2 / g. Therefore, in an embodiment, each of the layers may each have a 2 / g to 10m 2 / g, from 3m 2 / g to 10m 2 / g, from 3m 2 / g to 8m 2 / g, from 5m 2 / g to 8m 2 / g, from 1m 2 / g to 3m 2 / g, from 3m 2 / g to 5m 2 / g, from 2m 2 / g to 3m 2 / g, from 1m 2 / g to 2m 2 / g, or from 0.5m 2 / g to 1m 2 It should be understood that in embodiments, one or more of core layer 110, first conformal dielectric layer 120, conformal absorber layer 130, and second conformal dielectric layer 140 may have the same surface area, and in other embodiments, one or more of core layer 110, first conformal dielectric layer 120, conformal absorber layer 130, and second conformal dielectric layer 140 may have different surface areas.

[0101] The specific surface area (SSA) of the material was obtained by collecting isotherms at 76 K using nitrogen physical adsorption by fitting 13 points collected from P / P0≈0.06-0.3 to the Brunauer-Emmett-Teller (BET) equation. Additional adsorption points were collected at different P / P0 (up to P / P0≈0.95) and then desorbed back to P / P0≈0.06. The total pore volume was determined by the volume of nitrogen adsorbed at P / P0 0.95, and the average pore diameter was calculated using the Barrett Joyner Halenda (BJH) method.

[0102] In an embodiment, the multilayer structure may have a D measured by the BET equation. 50 diameter, the amount of adsorbed gas that builds up a monolayer on the surface can be calculated from the measured isotherms. The molecular weight in this monolayer multiplied by the space required for one molecule gives the BET D 50 , BET D 50From 1 μm to 500 μm, such as from 10 μm to 500 μm, from 20 μm to 500 μm, from 25 μm to 500 μm, from 50 μm to 500 μm, from 100 μm to 500 μm, from 150 μm to 500 μm, from 200 μm to 500 μm, from 250 μm to 500 μm, from 300 μm to 500 μm, from 350 μm to 500 μm, from 400 μm to 500 μm, from 450 μm to 500 μm, from 5 μm to 450 μm, from 10 μm to 450 μm, from 20 μm to 4 50μm, from 25μm to 450μm, from 50μm to 450μm, from 100μm to 450μm, from 150μm to 450μm, from 200μm to 450μm, from 250μm to 450μm, from 300μm to 450μm, from 350μm to 450μm, from 400μm to 450μm, from 5μm to 400μm, from 10μm to 400μm, from 20μm to 400μm, from 25μm to 400μm, from 50μm to 400μm, from 100μm to 400μm, from 150 μm to 400 μm, from 200 μm to 400 μm, from 250 μm to 400 μm, from 300 μm to 400 μm, from 350 μm to 400 μm, from 5 μm to 350 μm, from 10 μm to 350 μm, from 20 μm to 350 μm, from 25 μm to 350 μm, from 50 μm to 350 μm, from 100 μm to 350 μm, from 150 μm to 350 μm, from 200 μm to 350 μm, from 250 μm to 350 μm, from 300 μm to 350 μm, from 5 μm to 300 μm,From 10μm to 300μm, from 20μm to 300μm, from 25μm to 300μm, from 50μm to 300μm, from 100μm to 300μm, from 150μm to 300μm, from 200μm to 300μm, from 250μm to 300μm, from 5μm to 250μm, from 10μm to 250μm, from 20μm to 250 μm, from 25 μm to 250 μm, from 50 μm to 250 μm, from 100 μm to 250 μm, from 150 μm to 250 μm, from 200 μm to 250 μm, from 5 μm to 200 μm, from 10 μm to 200 μm, from 20 μm to 200 μm, from 25 μm to 200 μm, from 50 μm to 200 μm, from 100 μm to 200 μm, from 150 μm to 200 μm, from 5 μm to 150 μm, from 10 μm to 150 μm, from 20 μm to 150 μm, from 25 μm to 15 0μm, from 50μm to 150μm, from 100μm to 150μm, from 5μm to 100μm, from 10μm to 100μm, from 20μm to 100μm, from 25μm to 100μm, from 50μm to 100μm, from 5μm to 50μm, from 10μm to 50μm, from 20μm to 50μm, from 25μm to 50μm, from 5μm to 25μm, from 10μm to 25μm, from 20μm to 25μm, from 5μm to 20μm, from 10μm to 20μm or from 5μm to 10μm. ,

[0103] The aspect ratio of the multilayer structures according to the embodiments disclosed and described herein as measured by electron microscopy (TEM, SEM) is from 1 to 100, such as from 5 to 100, from 10 to 100, from 20 to 100, from 30 to 100, from 40 to 100, from 50 to 100, from 60 to 100, from 70 to 100, from 80 to 100, from 90 to 100, from 5 to 90, from 10 to 90, from 20 to 90, from 30 to 90, from 40 to 90, from 50 to 90, from 60 to 90, from 70 to 90, from 80 to 90, from 5 to 80, from 10 to 80, from 20 to 80, from 30 to 80, from 40 to 80, from 50 to 80, from 60 to 80, from 80 to 90 from 5 to 40, from 10 to 40, from 20 to 40, from 30 to 40, from 10 to 40, from 20 to 40, from 30 to 40, from 5 to 30, from 10 to 30, from 20 to 30, from 5 to 20, from 10 to 20, or from 5 to 10, wherein both cross-sections and surfaces are measured based on a large number of thin slices.

[0104] The embodiments of the multilayer structure 100 described above have a hue shift of less than 30° in Lab color space when viewed from an angle of 0° to 45°, such as less than 25°, less than 20°, less than 15°, or less than 10°.

[0105] In one or more embodiments, the multilayer structure 100 includes: a reflective core layer 110 made of Al; a conformal protective layer 111 made of SiO2 coating the reflective core layer 110; a conformal dielectric layer 120 made of TiO2 coating the conformal protective layer 111; a conformal barrier layer 121 made of Al2O3 coating the conformal dielectric layer 120; and a conformal metal absorption layer 130 made of W coating the conformal barrier layer 121.

[0106] In one or more embodiments, the multilayer structure 100 includes: a reflective core layer 110 made of Al; a conformal protective layer 111 made of SiO2 coating the reflective core layer 110; a first conformal dielectric layer 120 made of TiO2 coating the conformal protective layer 111; a conformal barrier layer 121 made of Al2O3 coating the conformal dielectric layer 120; a conformal metal absorption layer 130 made of W coating the conformal barrier layer 121; a second conformal barrier layer 131 made of SiO2 or Al2O3 coating the conformal metal absorption layer 130; and a second conformal dielectric layer 140 made of TiO2 coating the second conformal barrier layer 131.

[0107] In one or more embodiments, the multilayer structure 100 includes: a reflective core layer 110 made of Al; a first conformal protective layer 111 made of SiO2 coating the reflective core layer 110; a first conformal dielectric layer 120 made of TiO2 coating the conformal protective layer 111; a conformal barrier layer 121 made of Al2O3 coating the conformal dielectric layer 120; a conformal metal absorption layer 130 made of W coating the conformal barrier layer 121; a second conformal barrier layer 131 made of SiO2 or Al2O3 coating the conformal metal absorption layer; a second conformal dielectric layer 140 made of TiO2 coating the second conformal barrier layer 131; and a conformal outer layer 141 made of SiO2 coating the second conformal dielectric layer.

[0108] In one or more embodiments, the multilayer structure 100 includes: a reflective core layer 110 made of Al; a conformal protective layer 111 made of SiO2 coating the reflective core layer 110; a conformal dielectric layer 120 made of Fe2O3 coating the conformal protective layer 111; a conformal barrier layer 121 made of Al2O3 coating the conformal dielectric layer 120; and a conformal metal absorption layer 130 made of W coating the conformal barrier layer 121.

[0109] In one or more embodiments, the multilayer structure 100 includes: a reflective core layer 110 made of Al; a conformal protective layer 111 made of SiO2 coating the reflective core layer 110; a first conformal dielectric layer 120 made of Fe2O3 coating the conformal protective layer 111; a conformal barrier layer 121 made of Al2O3 coating the conformal dielectric layer 120; a conformal metal absorption layer 130 made of W coating the conformal barrier layer 121; a second conformal barrier layer 131 made of SiO2 or Al2O3 coating the conformal metal absorption layer; and a second conformal dielectric layer 140 made of Fe2O3 or TiO2 coating the second conformal barrier layer 131.

[0110] In one or more embodiments, the multilayer structure 100 includes: a reflective core layer 110 made of Al; a conformal protective layer 111 made of SiO2 coating the reflective core layer 110; a first conformal dielectric layer 120 made of Fe2O3 coating the conformal protective layer 111; a conformal barrier layer 121 made of Al2O3 coating the conformal dielectric layer 120; a conformal metal absorption layer 130 made of W coating the conformal barrier layer 121; a second conformal barrier layer 131 made of SiO2 or Al2O3 coating the conformal metal absorption layer; a second conformal dielectric layer 140 made of Fe2O3 or TiO2 coating the second conformal barrier layer 131; and a conformal outer layer 141 made of SiO2 coating the second conformal dielectric layer.

[0111] The multilayer structure in the embodiments disclosed herein can be used as a pigment (e.g., a coating pigment for painting a coating of an object) or a continuous film applied to an object. When used as a pigment, at least one of a coating binder and a filler can be used and mixed with the pigment to provide a coating showing a high chromaticity structural color. In addition, other additives can be added to the multilayer structure to contribute to the compatibility of the multilayer structure in the coating system. Exemplary compatibility enhancing additives include silane surface treatments that coat the outside of the multilayer structure and improve the compatibility of the multilayer structure in the coating system. Such a coating system or film can be used on any article including a motor vehicle.

[0112] A first aspect includes a reflective color multilayer structure comprising: a core layer; a conformal dielectric layer overlying the core layer; a conformal barrier layer overlying the conformal dielectric layer; and a conformal absorbing layer overlying the conformal barrier layer.

[0113] The second aspect includes the multilayer structure of the first aspect, further comprising a conformal protective layer encapsulating the core layer.

[0114] A third aspect includes the multilayer structure of the first aspect or the second aspect, further comprising: a second conformal barrier layer encapsulating the conformal absorber layer; and a second conformal dielectric layer encapsulating the second conformal barrier layer.

[0115] The fourth aspect includes the multilayer structure of any one of the first to third aspects, wherein the multilayer structure reflects a single narrow band of visible light when exposed to broadband electromagnetic radiation, and the single narrow band of visible light includes: when the multilayer structure is exposed to broadband electromagnetic radiation and observed from an angle between 0° and 45° relative to a direction orthogonal to an outer surface of the multilayer structure, the color shift of the single narrow band of visible light is less than 30° measured in the Lab color space.

[0116] A fifth aspect includes the multilayer structure of any one of the first to fourth aspects, wherein the core layer has a thickness between 20 nm and 100 μm.

[0117] The sixth aspect includes a multilayer structure of any one of the first to fifth aspects, wherein the conformal dielectric layer is formed of TiO2, ZnS, ZrO2, HfO2, Fe3O4, AlAs, Fe2O3, PbS, GaAs, InAs, SiO2, MgF2, KBr, ZnO or Al2O3, and the conformal dielectric layer has a thickness between 5nm and 500nm.

[0118] The seventh aspect includes the multilayer structure of any one of the first to sixth aspects, wherein the conformal absorption layer is formed by W, Cr, Ge, Ni, stainless steel, Pd, Ti, Si, V, TiN, Co, Mo, Nb, iron oxide or a combination thereof, and the conformal metal absorption layer has a thickness between 2 nm and 50 nm.

[0119] The eighth aspect includes the multilayer structure of any one of the first to seventh aspects, wherein the conformal barrier layer is formed of Al2O3, SiO2, MgF2, KBr or ZnO, and the conformal barrier layer has a thickness less than or equal to 50 nm.

[0120] The ninth aspect includes a multilayer structure of any one of aspects from the third to the eighth aspect, wherein the second conformal dielectric layer is formed of TiO2, ZnS, ZrO2, HfO2, Fe3O4, AlAs, Fe2O3, PbS, GaAs, InAs, SiO2, MgF2, KBr, ZnO or Al2O3 and has a thickness between 5nm and 500nm, the conformal protective layer is formed of SiO2, MgF2, KBr, ZnO or Al2O3 and has a thickness less than or equal to 50nm, and the second conformal barrier layer is formed of SiO2, MgF2, KBr, ZnO or Al2O3 and has a thickness less than or equal to 50nm.

[0121] The tenth aspect includes the multilayer structure of any one of the first to ninth aspects, wherein the core layer is formed of Al, the conformal dielectric layer is formed of TiO2 or Fe2O3, the conformal barrier layer is formed of Al2O3, and the conformal absorption layer is formed of W.

[0122] The eleventh aspect includes the multilayer structure of any one of the first to ninth aspects, wherein the core layer is formed of Al, the conformal protective layer is formed of SiO2, the conformal dielectric layer is formed of TiO2 or Fe2O3, the conformal barrier layer is formed of Al2O3, the conformal metal absorption layer is formed of W, the second conformal barrier layer is formed of SiO2 or Al2O3, and the second conformal dielectric layer is formed of TiO2 or Fe2O3.

[0123] A twelfth aspect includes the multilayer structure of any one of the first to eleventh aspects, wherein each of the core layer, the conformal dielectric layer, and the conformal absorber layer has a dielectric constant less than or equal to 0.030 cm 3 / g of pore volume.

[0124] A thirteenth aspect includes the multilayer structure of any one of the first to twelfth aspects, wherein each of the core layer, the conformal dielectric layer, and the conformal absorber layer has a thickness less than or equal to 0.005 cm 3 / g of pore volume.

[0125] A fourteenth aspect includes the multilayer structure of any one of the first to thirteenth aspects, wherein each of the core layer, the conformal dielectric layer, and the conformal absorber layer has a dielectric constant less than or equal to 100 m 2 / g of surface area.

[0126] A fifteenth aspect includes the multilayer structure of any one of the first to fourteenth aspects, wherein each of the core layer, the conformal dielectric layer, and the conformal absorber layer has a dielectric constant less than or equal to 3 m 2 / g of surface area.

[0127] A sixteenth aspect includes the multilayer structure of any one of the first to fifteenth aspects, wherein the multilayer structure has a D from 1 μm to 500 μm. 50 diameter.

[0128] A seventeenth aspect includes the multilayer structure of any one of the first to sixteenth aspects, wherein the multilayer structure has an aspect ratio from 1 to 100.

[0129] The eighteenth aspect includes a method for forming a multilayer structure of any one of the first to seventeenth aspects, the method comprising: depositing a conformal dielectric layer onto a core layer by CVD or ALD; depositing a conformal barrier layer onto the conformal dielectric layer by ALD; and depositing a conformal absorption layer onto the conformal dielectric layer by ALD.

[0130] A nineteenth aspect includes a coating system comprising: a binder; and the multi-layer structure of any one of the first to seventeenth aspects.

[0131] A twentieth aspect comprises a motor vehicle comprising the coating system of the nineteenth aspect.

[0132] It should be noted that the terms "substantially" and "approximately" may be used herein to represent the inherent degree of uncertainty that may be attributed to any quantitative comparison, value, measurement or other representation. These terms are also used herein to represent the degree by which a quantitative representation may vary from a stated reference without resulting in a change in the basic function of the subject matter at issue.

[0133] Example

[0134] The embodiments will be further explained by the following examples.

[0135] As described above, high volume ALD production may result in overlapping of adjacent dielectric and absorber layers, which may result in degraded optical properties of the multilayer structure. It is believed that such overlapping occurs due to the high porosity of the dielectric layers (such as the TiO2 layer), which allows overlapping with absorber layers (such as the W layer) applied by ALD, since the metal can be impregnated into the pores of the dielectric layer. In the presence of barrier or protective layers, all layers are well separated, and therefore the optical properties of all layers are well predicted by simulation.

[0136] Example 1

[0137] The multilayer structure is formed using an ALD process. The multilayer structure includes: an aluminum reflective core layer; a conformal SiO2 first protective layer covering the reflective core layer; a conformal TiO2 dielectric layer covering the conformal SiO2 first protective layer; a conformal Al2O3 barrier layer covering the conformal TiO2 dielectric layer; and a conformal W metal absorption layer covering the conformal Al2O3 barrier layer.

[0138] Fig. 6A is a TEM image of the multilayer structure formed. Fig. 6A As shown in , each layer is clear, independent, and has a smooth surface. Figure 6B is a further magnified TEM image of the as-formed multilayer structure, and also shows clear, independent and smooth layers. Figure 6C is a TEM image in which the element aluminum is highlighted. Figure 6C It is shown that the Al reflective core layer 710 is very clear and has a smooth surface, and it also shows a clear Al2O3 barrier layer 731, both of which have smooth surfaces. Fig.6D is a TEM image in which elemental oxygen is highlighted. Fig.6D A clear SiO2 protective layer 711, a clear TiO2 dielectric layer 720, and a clear Al2O3 barrier layer 731 are shown, all of which have smooth surfaces and there is no significant overlap between the various oxygen-containing layers. Fig. 6E This is a TEM image with the element tungsten highlighted. Fig. 6E As shown in FIG. 7 , the W absorption layer 730 is clear and has a smooth surface. Fig. 6E It is also shown that tungsten has not penetrated into the TiO 2 dielectric layer 720 . Fig. 6F is a TEM image in which the element titanium is highlighted. Fig. 6FA clear TiO 2 dielectric layer 720 is shown having a smooth surface and no infiltration of TiO 2 into the Al reflective core layer 710 or the W absorber layer 730 .

[0139] Comparative Example 1

[0140] The multilayer structure is formed using an ALD process. The multilayer structure includes: an aluminum reflective core layer; a conformal SiO2 first protective layer covering the reflective core layer; a conformal TiO2 dielectric layer covering the conformal SiO2 first protective layer; and a conformal W metal absorption layer covering the conformal TiO2 dielectric layer. There is no barrier layer between the TiO2 dielectric layer and the W absorption layer.

[0141] Fig. 7A is a TEM image of the multilayer structure formed. Fig. 7A As shown in FIG, tungsten infiltrates from the W absorber layer into the TiO2 dielectric layer. Figure 7B is a further magnified TEM image of the as-formed multilayer structure and also shows the infiltration of W into the TiO2 dielectric layer. Figure 7C is a TEM image in which the element aluminum is highlighted. Figure 7C The Al reflective core layer 710 is shown to be very clear and has a smooth surface provided in part by the SiO2 protective layer. Fig.7D is a TEM image in which elemental oxygen is highlighted. Fig.7D A dense oxygen concentration is shown at the bottom of the TiO 2 dielectric layer (ie, closer to the Al reflective core layer), where less tungsten can penetrate. Fig. 7E This is a TEM image with the element tungsten highlighted. Fig. 7E As shown in , there is no protective layer and W penetrates into the TiO2. Figure 7F is a TEM image in which the element titanium is highlighted. Figure 7F A high concentration of Ti is shown at the bottom of the TiO 2 dielectric layer (ie, closer to the Al reflective core layer), where less tungsten can penetrate.

[0142] As shown in Example 1 and Comparative Example 1 above, by depositing an Al2O3 barrier layer between the TiO2 dielectric layer and the W absorption layer, the multilayer structure has well-separated dielectric layers and absorption layers, which produces a multilayer structure with improved chromaticity compared to the multilayer structure in which no barrier layer exists between the TiO2 dielectric layer and the W absorption layer.

[0143] It is obvious to those skilled in the art that various modifications and changes may be made to the embodiments described herein without departing from the spirit and scope of the subject matter claimed. Therefore, the specification is intended to cover modifications and changes of the various embodiments described herein, as long as such modifications and changes are within the scope of the appended claims and their equivalents.

Claims

1. A multilayer structure reflecting color, comprising: Core layer; a conformal dielectric layer covering the core layer; a conformal barrier layer covering the conformal dielectric layer; as well as A conformal absorbent layer covers the conformal barrier layer. 2 . The multilayer structure according to claim 1 , further comprising a conformal protective layer covering the core layer.

3. The multilayer structure according to claim 2, further comprising: a second conformal barrier layer covering the conformal absorbent layer; as well as A second conformal dielectric layer encapsulating the second conformal barrier layer.

4. The multilayer structure according to claim 1, wherein The multilayer structure reflects a single narrow band of visible light when exposed to broadband electromagnetic radiation, the single narrow band of visible light comprising: When the multilayer structure is exposed to broadband electromagnetic radiation and viewed at an angle between 0° and 45° relative to a direction normal to an outer surface of the multilayer structure, the color of the single narrow band of visible light shifts by less than 30° measured in Lab color space.

5. The multilayer structure according to claim 1, wherein The core layer has a thickness between 20 nm and 100 μm.

6. The multilayer structure according to claim 1, wherein The conformal dielectric layer is formed of TiO2, ZnS, ZrO2, HfO2, Fe3O4, AlAs, Fe2O3, PbS, GaAs, InAs, SiO2, MgF2, KBr, ZnO or Al2O3, and The conformal dielectric layer has a thickness between 5 nm and 500 nm.

7. The multilayer structure according to claim 1, wherein The conformal absorber layer is formed of W, Cr, Ge, Ni, stainless steel, Pd, Ti, Si, V, TiN, Co, Mo, Nb, iron oxide, or a combination thereof, and The conformal absorbing layer has a thickness between 2 nm and 50 nm.

8. The multilayer structure according to claim 1, wherein The conformal barrier layer is formed of Al2O3, SiO2, MgF2, KBr or ZnO, and The conformal barrier layer has a thickness less than or equal to 50 nm.

9. The multilayer structure according to claim 3, wherein: The second conformal dielectric layer is formed of TiO2, ZnS, ZrO2, HfO2, Fe3O4, AlAs, Fe2O3, PbS, GaAs, InAs, SiO2, MgF2, KBr, ZnO or Al2O3 and has a thickness between 5 nm and 500 nm, The conformal protective layer is formed of SiO2, MgF2, KBr, ZnO or Al2O3 and has a thickness less than or equal to 50 nm, and The second conformal barrier layer is formed of SiO2, MgF2, KBr, ZnO or Al2O3 and has a thickness less than or equal to 50 nm.

10. The multilayer structure according to claim 1, wherein The core layer is formed of Al, The conformal dielectric layer is formed of TiO2 or Fe2O3, The conformal barrier layer is formed of Al2O3, and The conformal absorber layer is formed of W.

11. The multilayer structure according to claim 3, wherein: The core layer is formed of Al, The conformal protective layer is formed of SiO2 or Al2O3, The conformal dielectric layer is formed of TiO2 or Fe2O3, The conformal barrier layer is formed of Al2O3, The conformal absorbing layer is formed of W, The second conformal barrier layer is formed of SiO2 or Al2O3, and The second conformal dielectric layer is formed of TiO2 or Fe2O3.

12. The multilayer structure according to claim 1, wherein Each of the core layer, the conformal dielectric layer, and the conformal absorber layer has a thickness less than or equal to 0.030 cm 3 / g of pore volume.

13. The multilayer structure according to claim 1, wherein Each of the core layer, the conformal dielectric layer, and the conformal absorber layer has a thickness less than or equal to 0.005 cm 3 / g of pore volume.

14. The multilayer structure according to claim 1, wherein Each of the core layer, the conformal dielectric layer, and the conformal absorber layer has a dielectric constant less than or equal to 100 m 2 / g of surface area.

15. The multi-layer structure according to claim 1, wherein Each of the core layer, the conformal dielectric layer, and the conformal absorber layer has a thickness less than or equal to 5 m 2 / g of surface area.

16. The multilayer structure according to claim 1, wherein The multilayer structure has a D from 1 μm to 500 μm. 50 diameter.

17. The multi-layer structure according to claim 1, wherein: The multilayer structure has an aspect ratio from 1 to 100.

18. A method for forming the multilayer structure according to claim 1, the method comprising: depositing the conformal dielectric layer onto the core layer by CVD or ALD; depositing the conformal barrier layer onto the conformal dielectric layer by ALD; as well as The conformal absorber layer is deposited onto the conformal dielectric layer by ALD.

19. A coating system comprising: Binder; as well as The multilayer structure according to claim 1.

20. A motor vehicle comprising the coating system according to claim 19.

Images