A metal and dielectric composite nano-patterned substrate and its preparation method and application

Abstract

The present invention provides a nano-patterned substrate composed of a metal and dielectric composite, and its preparation method and application. The nano-patterned substrate comprises a substrate, a periodic three-dimensional dielectric nanostructure, and metal nanoparticles; the three-dimensional dielectric nanostructure is disposed on the substrate; the metal nanoparticles are confined within the three-dimensional dielectric nanostructure; and the nano-patterned substrate achieves ultra-high pixel resolution and structural color rendering with a wide color gamut. The preparation method provided by the present invention heat-treats a metal nanofilm coated on a periodic three-dimensional dielectric nanostructure array. By utilizing the excellent thermal conductivity and low melting point of metallic silver, the heated molten silver or silver alloy migrates and converges along the dielectric structure interface. Under the confinement of the three-dimensional dielectric nanostructure, the metal nanoparticles are formed within the dielectric nanostructure, thereby obtaining a nano-patterned substrate composed of a metal and dielectric composite.

Description

Technical Field

[0001] The present invention belongs to the technical field of nanomaterials, and in particular relates to a nano-patterned substrate composite of metal and dielectric, and a preparation method and application thereof. Background Art

[0002] Patterned metal / precious metal nanostructures not only have important scientific significance in the fields of optics, micro-nanoelectronics, optoelectronics, information technology, energy conversion, environment and catalysis, sensing, etc., but also have great application value and potential. As for the precious metal silver, it not only has excellent electrical and thermal conductivity, but also has a relatively low price and processability, and thus has gained widespread favor. In addition, silver nanostructures have a very prominent plasmon effect in the visible light region. By designing and tailoring their morphology, size, and arrangement, their plasmon effect can be effectively controlled, and precise control of the peak position, number, resonance intensity, and intensity uniformity of their surface plasmon resonance peaks can be achieved. Therefore, the design and controllable preparation of silver nanostructures and their patterned arrays can not only meet the needs of practical applications, but also provide accurate structural models for conducting basic scientific research in the fields of light, electricity, magnetism, and heat.

[0003] Silver nanostructures demonstrate unique advantages in structural color rendering, a prime application of the metal plasmon effect. By designing their structural units, they can effectively manipulate light wavefronts across different wavelengths, enabling the display of diverse colors. However, due to the high absorption of light by plasmon resonance in the visible light band, metal nanostructures exhibit significant light losses. However, dielectric materials, with their high refractive index and low loss, can compensate for the shortcomings of metal nanostructures. Therefore, the integration of metal and dielectric nanostructures could theoretically achieve structural color rendering with a wide color gamut, high saturation, and high resolution.

[0004] Although in theory the combination of metal and dielectric can show complementary advantages in structural color display, the composite structure needs to be carefully designed. On the one hand, the shape, symmetry, three-dimensional size and array arrangement of the metal structural unit need to be delicately designed to regulate the plasmon resonance mode to improve the effective reflectivity and achieve high display brightness and saturation. On the other hand, the design of the dielectric structure needs to make full use of the Mie scattering and metal plasmon resonance coupling effect, and further expand the display color gamut and improve the intensity and saturation by matching the material and size of the metal structure. In addition, the design of the metal and dielectric composite structure must also take into account the cost, efficiency and reliability of its preparation method.

[0005] Therefore, developing a metal and dielectric composite nanostructure with low cost, high efficiency and excellent structural color rendering performance is an urgent problem that needs to be solved by those skilled in the art. Summary of the Invention

[0006] The object of the present invention is to provide a nano-patterned substrate of a metal and dielectric composite, and a preparation method and application thereof, wherein the nano-patterned substrate realizes structural color display with ultra-high pixel resolution and wide color gamut, and the arrangement mode of metal nanoparticles in the nano-patterned substrate depends on the design pattern of the dielectric structure, thereby realizing artificially controllable design and efficient preparation of the metal and dielectric composite nanostructured substrate; the preparation method heat-treats the metal nanofilm plated on the periodic three-dimensional dielectric nanostructure array, and utilizes the excellent thermal conductivity and low melting point properties of metallic silver to cause the heated molten silver or silver alloy to migrate and converge along the dielectric structure interface, and under the confinement of the three-dimensional dielectric nanostructure, the metal nanoparticles are formed in the dielectric nanostructure, thereby obtaining a nano-patterned substrate of a metal and dielectric composite.

[0007] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a metal and dielectric composite nano-patterned substrate, wherein the nano-patterned substrate comprises a substrate, a periodic three-dimensional dielectric nanostructure, and metal nanoparticles;

[0009] The three-dimensional dielectric nanostructure is disposed on a substrate;

[0010] The metal nanoparticles are confined in a three-dimensional dielectric nanostructure.

[0011] It is worth noting that the confinement is to use a periodic three-dimensional dielectric structural framework to confine single metal nanoparticles in the grid of the structural framework, so that the metal nanoparticles and the three-dimensional dielectric nanostructure are arranged in a transverse alternating manner, which is completely different from the interface enhancement form formed by the currently reported metal-dielectric longitudinal contact.

[0012] This invention leverages the excellent thermal conductivity and low melting point of metallic silver, along with the precise positioning and size control of three-dimensional dielectric nanostructures. Through ingenious structural design, a nanopatterned substrate composed of a metal and dielectric composite is created. The arrangement of the metal nanoparticles in the nanopatterned substrate is determined by the design pattern of the dielectric structure, thus enabling the controlled design and efficient preparation of the nanostructured substrate. The introduction of the three-dimensional dielectric nanostructures leads to a coupling effect between Mie scattering and metal plasmon resonance, further expanding the display color gamut and improving intensity and saturation.

[0013] As a preferred technical solution of the present invention, the period of the three-dimensional dielectric nanostructure is 10-1200 nm, for example, it can be 10 nm, 50 nm, 100 nm, 200 nm, 400 nm, 600 nm, 800 nm, 1000 nm or 1200 nm, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0014] Preferably, the height of the three-dimensional dielectric nanostructure is 200-2000 nm, for example, it can be 200 nm, 400 nm, 600 nm, 800 nm, 1000 nm, 1200 nm, 1400 nm, 1600 nm, 1800 nm or 2000 nm, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0015] Preferably, the sidewall width of the three-dimensional dielectric nanostructure is 12-200 nm, for example, 12 nm, 50 nm, 100 nm or 200 nm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0016] As a preferred technical solution of the present invention, the particle size of the metal nanoparticles is 250-1000 nm, for example, it can be 250 nm, 400 nm, 600 nm, 800 nm or 1000 nm, but is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable.

[0017] Preferably, the metal nanoparticles are silver and / or silver alloy.

[0018] As a preferred technical solution of the present invention, the substrate includes any one of silicon, silicon-based, quartz, metal, metal oxide, Group III-V semiconductor or diamond, or a combination of at least two of them. The typical but non-limiting combinations include a combination of silicon-based and quartz, a combination of quartz and Group III-V semiconductor, or a combination of Group III-V semiconductor and diamond, etc.

[0019] Preferably, the material of the three-dimensional dielectric nanostructure includes any one or a combination of at least two of silicon, silicon-based, metal oxide, Group III-V semiconductor, dielectric or insulating materials. Typical but non-limiting combinations include a combination of silicon and silicon-based, a combination of silicon-based and metal oxide, or a combination of Group III-V semiconductor and insulating material, etc.

[0020] In the present invention, the three-dimensional dielectric nanostructured material has good physical and chemical properties and structural stability during heat treatment.

[0021] In a second aspect, the present invention provides a method for preparing the nano-patterned substrate according to the first aspect, the preparation method comprising the following steps:

[0022] (1) preparing a periodic three-dimensional dielectric nanostructure on the substrate surface to obtain an intermediate base;

[0023] (2) depositing a metal nanofilm on the three-dimensional dielectric nanostructure of the intermediate substrate in step (1), and then sequentially performing heat treatment and surface cleaning treatment to obtain a nano-patterned substrate.

[0024] In the present invention, a metal and dielectric composite nanostructure array can be obtained through a one-step heating treatment; during the formation of the metal nanostructure, the three-dimensional dielectric nanostructure plays a dual role of positioning and size control.

[0025] The preparation method described in the present invention utilizes the "trapping" effect of the periodic three-dimensional dielectric nanostructure framework on the metal nanoparticles therein. By designing the size of the periodic three-dimensional dielectric nanostructure and the thickness of the metal nanofilm and changing the heat treatment conditions, a nano-patterned substrate of dielectric and metal hybrid composite with various periods, shapes, and metal structure sizes can be obtained. The preparation method is simple in process and has universal applicability.

[0026] As a preferred technical solution of the present invention, the preparation method of the three-dimensional dielectric nanostructure in step (1) includes any one or a combination of at least two of the following: exposure to positive electron beam resist, exposure to negative electron beam resist, nanoimprinting, laser direct writing, metal deposition, dielectric layer precipitation, stripping or etching methods. The typical but non-limiting combination includes a combination of exposure to positive electron beam resist and exposure to negative electron beam resist, a combination of nanoimprinting and laser direct writing, a combination of metal deposition and dielectric layer precipitation, or a combination of stripping and etching, etc.

[0027] In the present invention, the three-dimensional dielectric nanostructure pattern can be artificially designed and tailored, can be prepared by various processing methods, and is applicable to various dielectric materials.

[0028] As a preferred technical solution of the present invention, the deposition method in step (2) includes any one of electron beam evaporation, thermal evaporation, magnetron sputtering or atomic layer deposition.

[0029] Preferably, the thickness of the metal nanofilm in step (2) is 1-500 nm, for example, 1 nm, 10 nm, 50 nm, 100 nm, 200 nm, 300 nm, 400 nm or 500 nm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0030] As a preferred technical solution of the present invention, after the heat treatment in step (2), the metal nanofilm forms single metal nanoparticles inside the three-dimensional dielectric nanostructure.

[0031] It is worth noting that although the melting point of bulk silver is about 961°C, the melting point of the nanosilver or silver alloy film deposited on the three-dimensional dielectric nanostructure is significantly lower. When the substrate is heated, the silver or silver alloy nanofilm attached to the three-dimensional dielectric nanostructure reaches the melting point and gradually melts, and migrates simultaneously toward the bottom and top along the sidewalls of the three-dimensional dielectric nanostructure. The dual effects of confinement and dewetting of the three-dimensional dielectric nanostructure lead to the formation of single metal particles inside it and dispersed small particles on its top; specifically: the part that migrates from the sidewall to the bottom merges with the metal nanofilm deposited at the bottom of the structure to form larger spherical particles, while the metal that migrates along the sidewall to the top of the structure forms smaller particles, which can eventually be removed.

[0032] It is worth noting that the metal nanoparticles obtained after heat treatment have high symmetry, and there are fewer plasmon resonance modes than structures with lower symmetry such as square columns and cylinders, and there is positioning redundancy between the formed nanoparticles. The above two factors jointly reduce the reflection loss, thereby improving the display intensity and monochromaticity. In addition, since the display color gamut range is more sensitive to the size change of the metal structure perpendicular to the substrate direction, and the size of the nano-metal structure provided by the present invention is determined by the size of the three-dimensional medium nanostructure, therefore, by designing three-dimensional medium nanostructures of different sizes, it is possible to obtain metal nanoparticles of multiple sizes (especially perpendicular to the substrate direction) on the same substrate at one time, so that its display color gamut and overall intensity are greatly improved. Conventional methods are difficult to achieve efficient preparation of metal structures with size spans in this vertical direction.

[0033] Preferably, the heat treatment in step (2) is carried out under protective gas.

[0034] In the present invention, the protective gas includes nitrogen to avoid oxidation.

[0035] Preferably, the temperature of the heat treatment in step (2) is 150-1200°C, for example, it can be 150°C, 300°C, 400°C, 500°C, 700°C, 900°C, 1000°C, 1100°C or 1200°C, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0036] Preferably, the holding time of the heat treatment in step (2) is 2 min-5 h, for example, it can be 2 min, 10 min, 30 min, 60 min, 1.5 h, 2 h, 3 h, 4 h or 5 h, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0037] In the present invention, the heat treatment in step (2) is carried out in an annealing furnace, and after the heat treatment is completed, the temperature is lowered to room temperature.

[0038] As a preferred technical solution of the present invention, the surface cleaning treatment in step (2) includes: applying a mixture of PDMS and a curing agent on the substrate, then heating and curing it, peeling off the PDMS film to remove the metal nanoparticles on the top of the structure or using a peeling tape to remove the metal nanoparticles on the top of the structure.

[0039] In the present invention, a thin film formed of polydimethylsiloxane (PDMS) is used to remove most of the metal nanoparticles distributed on the top of the structure.

[0040] Preferably, the volume ratio of the PDMS and the curing agent is (5-12):1, for example, it can be 5:1, 7:1, 8:1, 9:1, 10:1, 11:1 or 12:1, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0041] Preferably, the heating and curing temperature is 60-85°C, for example, it can be 60°C, 64°C, 68°C, 70°C, 74°C, 78°C, 80°C, 82°C or 85°C, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0042] Preferably, the heating and curing time is 0.1-12 hours, for example, it can be 0.1h, 0.5h, 1h, 3h, 5h, 7h, 9h, 10h or 12h, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0043] In a third aspect, the present invention provides an application of the nano-patterned substrate as described in the first aspect in color display.

[0044] It is worth noting that three-dimensional dielectric nanostructures offer the advantage of low color loss, while metal nanostructures offer the advantage of high pixel resolution. By leveraging the coupling effect between Mie scattering and metal plasmon resonance, and by designing the substrate based on the relationship between the geometric dimensions of the metal and dielectric nanostructures and their characteristic reflectance spectra, this approach achieves structural color rendering with high pixel resolution, high purity, and a wide color gamut.

[0045] The numerical range described in the present invention includes not only the point values ​​listed above, but also any point values ​​between the above numerical ranges that are not listed. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] (1) The present invention provides a metal and dielectric composite nano-patterned substrate. By confining metal nanoparticles in a three-dimensional dielectric nanostructure, the three-dimensional dielectric nanostructure has the advantage of low color loss. At the same time, it is completely different from the currently reported metal-dielectric interface enhancement form. The introduction mode of the three-dimensional dielectric nanostructure in the present invention will bring about the coupling effect between Mie scattering and metal plasmon resonance, further expanding the display color gamut, improving intensity and saturation, and has very broad application prospects. At the same time, it provides model structures and devices for the study of basic scientific problems such as the transmission and coupling of light, electricity, magnetism, and heat in nanoscale dielectric / metal composite structures;

[0048] (2) The preparation method provided by the present invention utilizes the "trapping" effect of the three-dimensional dielectric nanostructure framework on the metal therein, and can obtain a nanostructure array of metal and dielectric composites through a one-step heat treatment. By designing and preparing the periodic three-dimensional dielectric nanostructure size and metal nanofilm thickness and changing the heat treatment conditions, a nano-patterned substrate of dielectric and metal hybrid composite with various periods, shapes, and metal structure sizes can be obtained; the preparation method is simple in process, low in cost, and has universal applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 is a scanning electron microscope image of the hexagonal silicon oxide nanostructure array and silver nanoparticle composite substrate prepared in Example 1;

[0050] Figure 2 is a scanning electron microscope image of the composite substrate of quadrilateral silicon oxide nanostructure array and silver-copper alloy nanoparticles prepared in Example 2;

[0051] Figure 3 is a scanning electron microscope image of the hexagonal quartz nanostructure array and silver nanoparticle composite substrate prepared in Example 3;

[0052] Figure 4 is a scanning electron microscope image of the quadrilateral alumina nanostructure array and silver nanoparticle composite substrate prepared in Example 4;

[0053] Figure 5 is a scanning electron microscope image of the quadrilateral silicon oxide nanostructure array and silver nanoparticle composite substrate prepared in Example 5;

[0054] Figure 6 This is a scanning electron microscope image of a composite substrate of gallium arsenide nanostructure array and silver-copper alloy nanoparticles of one periodic unit prepared in Example 6;

[0055] Figure 7 This is a scanning electron microscope image of the hexagonal silicon oxide nanostructure array and silver nanoparticle composite substrate prepared in Comparative Example 1 before heat treatment;

[0056] Figure 8 The optical microscopy results of 22 metal and dielectric composite nano-patterned substrates used for color display.

[0057] Figure 9 This is an optical microscopic effect diagram of the nano-patterned substrate composed of 22 metals and dielectrics prepared in Comparative Example 1 when used for color display. DETAILED DESCRIPTION

[0058] The technical solution of the present invention is further described below by way of specific embodiments. It should be understood by those skilled in the art that the embodiments are merely to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0059] Example 1

[0060] This embodiment provides a method for preparing a metal-dielectric composite nano-patterned substrate, the preparation method comprising the following steps:

[0061] (1) Spin-coating a 200 nm thick negative electron beam resist HSQ on a cleaned silicon substrate, then exposing the electron beam resist using an electron beam, developing, and fixing to obtain a hexagonal periodic silicon oxide three-dimensional nanostructure array with a period of 470 nm, a height of 200 nm, and a sidewall width of 12 nm, thereby obtaining an intermediate substrate;

[0062] (2) using electron beam evaporation to deposit a 50 nm thick silver film on the silicon oxide three-dimensional nanostructure array on the intermediate substrate, and then heat-treating the substrate at 200°C for 45 minutes and then cooling it to room temperature. The particle size of the silver on the substrate is 310-350 nm;

[0063] (3) PDMS monomer and curing agent were mixed and coated on the silicon substrate described in step (2) in a volume ratio of 10:1, and then the substrate was heated at 60°C for 1 hour, and then cooled to room temperature, and the PDMS film was peeled off to remove the silver particles on the top of the structure to obtain a nano-patterned substrate composite of silver and silicon oxide (the scanning electron microscope image of which is shown in FIG. Figure 1 shown).

[0064] Depend on Figure 1 It can be seen that in the composite substrate prepared after heat treatment, silver nanoparticles are confined in a three-dimensional dielectric nanostructure, the silver nanoparticle confinement has high symmetry and there is positioning redundancy between the silver nanoparticles.

[0065] Example 2

[0066] This embodiment provides a method for preparing a metal and dielectric composite nano-patterned substrate, the preparation method comprising the following steps:

[0067] (1) A 350 nm thick negative electron beam gel AR-N 7520 was spin-coated on a cleaned silicon / silicon oxide composite substrate (500 nm thick). After electron beam exposure, development, and fixing, a quadrilateral periodic electron beam gel pattern was obtained with a period of 400 nm, a height of 550 nm, and a sidewall width of 50 nm. The negative electron beam gel structure was then used as a mask to etch silicon oxide with a depth of 500 nm by plasma-enhanced reactive ion etching. After de-gelling, an intermediate substrate was obtained.

[0068] (2) A 150 nm thick silver-copper alloy film was sputtered on the silicon oxide three-dimensional nanostructure array on the intermediate substrate using magnetron sputtering. The substrate was then heat treated at 500°C for 1.5 h and then cooled to room temperature. The particle size of the silver-copper alloy on the substrate was 250 nm.

[0069] (3) PDMS monomer and curing agent were mixed and coated on the silicon substrate described in step (2) in a volume ratio of 8:1, and then the substrate was heated at 85°C for 3 hours, and then cooled to room temperature, and the PDMS film was peeled off to remove the particles on the top of the structure to obtain a nano-patterned substrate composite of silver-copper alloy and silicon oxide (the scanning electron microscope image of which is shown in FIG. Figure 2 shown).

[0070] Example 3

[0071] This embodiment provides a method for preparing a metal and dielectric composite nano-patterned substrate, the preparation method comprising the following steps:

[0072] (1) Spin-coat a 350nm thick negative electron beam glue AR-N on the cleaned quartz substrate 7520, and then after electron beam exposure, development and fixing, a hexagonal periodic electron beam glue pattern is obtained, whose period is 1200nm and the side wall width is 160nm, and the negative electron beam glue structure is used as a mask to etch the quartz substrate, and the etching depth is 600nm. After the substrate is debonded, it is used as a nanoimprint template, and then it is hydrophobicized. The quartz substrate to be imprinted is coated with an imprint glue with a thickness of 550nm, the imprint pressure is set to 500N, the ultraviolet light time is 60s, and the imprinted pattern is obtained on the imprint glue after demolding; then the residual glue after imprinting is treated with an oxygen plasma cleaning machine, and then a silicon nitride film is plated. After the stripping process, the quartz is etched with the silicon nitride pattern as a mask, and the etching depth is 650nm. The silicon nitride is removed to obtain a hexagonal periodic quartz three-dimensional nanostructure array with a period of 1200nm, a side wall width of 160nm, and a depth of 650nm, and an intermediate substrate is obtained;

[0073] (2) A 500 nm thick silver film was sputtered on the quartz three-dimensional nanostructure array on the intermediate substrate using magnetron sputtering. The substrate was then heat treated at 950°C for 5 min and then cooled to room temperature. The silver particles on the substrate had a particle size of 1000 nm.

[0074] (3) Remove the silver particles on the top of the structure using a stripping tape to obtain a nano-patterned substrate composite of silver and quartz (the scanning electron microscope image of which is shown in FIG. Figure 3 shown).

[0075] Example 4

[0076] This embodiment provides a method for preparing a metal-dielectric composite nano-patterned substrate, the preparation method comprising the following steps:

[0077] (1) A 300 nm thick aluminum oxide film was prepared on a cleaned silicon substrate by electron beam evaporation, and then a 200 nm thick positive electron beam glue ZEP520A and a 10 nm thick conductive glue were spin-coated. After electron beam exposure, removal of the conductive glue, development and fixing, a quadrilateral periodic electron beam glue pattern was obtained, with a period of 900 nm, a height of 400 nm, and a sidewall width of 200 nm. The electron beam glue structure was then used as a mask to etch the aluminum oxide by plasma enhanced reactive ion etching to a depth of 500 nm. After de-gelling, an intermediate substrate was obtained;

[0078] (2) A 100 nm thick silver film was sputtered on the aluminum oxide three-dimensional nanostructure array on the intermediate substrate using magnetron sputtering. The substrate was then heat treated at 700 °C for 2 h and then cooled to room temperature. The particle size of the silver particles on the substrate was 500 nm.

[0079] (3) 3M tape was used to remove the silver particles on the top of the structure to obtain a nano-patterned substrate composite of silver and aluminum oxide (the scanning electron microscope image of which is shown in FIG. Figure 4 shown).

[0080] Example 5

[0081] This embodiment provides a method for preparing a metal-dielectric composite nano-patterned substrate, the preparation method comprising the following steps:

[0082] (1) A negative electron beam resist HSQ with a thickness of 200 nm was spin-coated on a cleaned sapphire substrate, and then an aluminum thin film conductive layer was sputtered using magnetron sputtering. The electron beam resist was then exposed to electron beam light. After removing the conductive layer, developing, and fixing, a rectangular periodic silicon oxide three-dimensional nanostructure array was obtained, wherein the period in two directions was 200 nm and 400 nm, respectively, and the sidewall width was 15 nm, thereby obtaining an intermediate substrate;

[0083] (2) A 35 nm thick silver film was deposited on the silicon oxide three-dimensional nanostructure array on the intermediate substrate using electron beam evaporation, and the substrate was then heat treated at 600° C. for 4.5 h and then cooled to room temperature. The silver particles on the substrate had a particle size of 250×150 nm (in this embodiment, the silver particles had an ellipsoidal structure);

[0084] (3) PDMS monomer and curing agent were mixed and coated on the sapphire substrate described in step (2) in a volume ratio of 10:1, and then the substrate was heated at 60°C for 1 hour, and then cooled to room temperature, and the PDMS film was peeled off to remove the silver particles on the top of the structure to obtain a nano-patterned substrate composite of silver and silicon oxide (the scanning electron microscope image of which is shown in FIG. Figure 5 shown).

[0085] Example 6

[0086] This embodiment provides a method for preparing a metal and dielectric composite nano-patterned substrate, the preparation method comprising the following steps:

[0087] (1) A negative electron beam gel HSQ with a thickness of 800 nm was spin-coated on a cleaned gallium arsenide substrate. After electron beam exposure, development, and fixing, a periodic grid structure unit with a grid wall width of >700 nm was obtained. Then, using the HSQ pattern as a mask, plasma-enhanced reactive ion etching was performed on the gallium arsenide to an etching depth of 750 nm. After removing the HSQ with a BOE solution, an intermediate substrate was obtained.

[0088] (2) A 350 nm thick silver-copper alloy film was sputtered on the GaAs three-dimensional nanostructure array on the intermediate substrate using magnetron sputtering. The substrate was then heat treated at 800 °C for 1.5 h and then cooled to room temperature. Because there are two dielectric lattice structures within a periodic unit, the particle size of the silver-copper alloy on the substrate is 500 or 700 nm.

[0089] (3) PDMS monomer and curing agent were mixed and coated on the silicon substrate described in step (2) in a volume ratio of 8:1, and then the substrate was heated at 85°C for 3 hours, and then cooled to room temperature, and the PDMS film was peeled off to remove the particles on the top of the structure to obtain a nano-patterned substrate composed of silver-copper alloy and gallium arsenide (the scanning electron microscope image of one periodic unit of the nano-patterned substrate is shown in FIG. Figure 6 shown).

[0090] Example 7

[0091] This embodiment provides a method for preparing a nano-patterned substrate composite of metal and dielectric. Except that the heat treatment temperature in step (2) is 100° C., other conditions are the same as those in Example 1.

[0092] When the heat treatment temperature is too low, the metallic silver film cannot melt and single silver particles cannot be formed inside the three-dimensional dielectric nanostructure.

[0093] Example 8

[0094] This embodiment provides a method for preparing a nano-patterned substrate composite of metal and dielectric. Except that the heat treatment temperature in step (2) is 1500° C., other conditions are the same as those in Example 1.

[0095] When the heat treatment temperature is too high, the sidewalls of the three-dimensional dielectric nanostructure are too narrow, causing the sidewalls to be easily deformed and unstable.

[0096] Comparative Example 1

[0097] This comparison provides a method for preparing a nano-patterned substrate of a metal and dielectric composite, except that step (2) is not subjected to heat treatment and step (3) is not performed, other conditions are the same as those in Example 1.

[0098] Figure 7 This is a scanning electron microscope image of the hexagonal silicon oxide nanostructure array and silver nanoparticle composite substrate obtained without heat treatment in this comparative example. Figure 7 It can be seen that the silver film in the composite substrate prepared without heat treatment is evenly covered on the dielectric structure.

[0099] Based on the Mie scattering and plasmon resonance coupling effect, by simulating the relationship between the geometric dimensions of metal and dielectric nanostructures and the characteristic reflection spectrum, any of the methods in Examples 1-6 above was selected to prepare a substrate. Then, the size of the silver nanoparticles of the substrate, the shape, height, wall thickness and period of the three-dimensional dielectric nanostructure were designed to prepare 22 composite nano-patterned substrates, which were applied to the display of multiple colors in the visible light wavelength, and the display effect was as follows: Figure 8 The 22 color display areas shown have a display color gamut range of 84% sRGB and a pixel resolution of only 130nm.

[0100] According to the method of comparative example 1, the substrate was prepared, and the thickness of the silver film of the substrate, the shape, height, wall thickness and period of the three-dimensional medium nanostructure were designed to obtain 22 kinds of composite nano-patterned substrates. When they were applied to visible light wavelength color display, the display effect was as follows: Figure 9 As shown, its display color gamut range is 6% sRGB and the pixel resolution is only 10μm (single vertical bar width).

[0101] The applicant declares that the present invention is intended to illustrate the detailed structural features of the present invention through the above-described embodiments, but the present invention is not limited to the above-described detailed structural features. This does not mean that the present invention must rely on the above-described detailed structural features in order to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent replacements for selected components, additions of auxiliary components, and selection of specific embodiments, etc., fall within the scope of protection and disclosure of the present invention.

Claims

1. A nano-patterned substrate composed of a metal and a dielectric, characterized in that: The nano-patterned substrate comprises a substrate, a periodic three-dimensional dielectric nanostructure and metal nanoparticles; The three-dimensional dielectric nanostructure is disposed on a substrate; The metal nanoparticles are confined in a three-dimensional dielectric nanostructure, wherein the confinement is achieved by confining a single metal nanoparticle in a grid of a periodic three-dimensional dielectric structural framework; The height of the three-dimensional dielectric nanostructure is 200-2000 nm; The sidewall width of the three-dimensional dielectric nanostructure is 12-200 nm; The particle size of the metal nanoparticles is 250-1000 nm; The method for preparing a nano-patterned substrate comprises the following steps: (1) preparing a periodic three-dimensional dielectric nanostructure on the substrate surface to obtain an intermediate base; (2) depositing a metal nanofilm on the three-dimensional dielectric nanostructure of the intermediate substrate in step (1), and then sequentially performing heat treatment and surface cleaning treatment to obtain a nano-patterned substrate; The temperature of the heat treatment in step (2) is 150-1200°C.

2. The nano-patterned substrate according to claim 1, characterized in that The period of the three-dimensional medium nanostructure is 10-1200 nm.

3. The nano-patterned substrate according to claim 1, wherein The metal nanoparticles are silver and / or silver alloy.

4. The nano-patterned substrate according to claim 1, wherein The substrate includes any one of silicon, quartz, metal, metal oxide, III-V semiconductor or diamond, or a combination of at least two thereof.

5. The nano-patterned substrate according to claim 1, wherein The material of the three-dimensional dielectric nanostructure includes any one of silicon, metal oxides or Group III-V semiconductors or a combination of at least two thereof.

6. A method for preparing a nano-patterned substrate according to any one of claims 1 to 5, characterized in that: The preparation method comprises the following steps: (1) preparing a periodic three-dimensional dielectric nanostructure on the substrate surface to obtain an intermediate base; (2) depositing a metal nanofilm on the three-dimensional dielectric nanostructure of the intermediate substrate in step (1), and then sequentially performing heat treatment and surface cleaning treatment to obtain a nano-patterned substrate; The temperature of the heat treatment in step (2) is 150-1200°C.

7. The preparation method according to claim 6, characterized in that The preparation method of the three-dimensional dielectric nanostructure in step (1) includes any one or a combination of at least two of the following: exposure positive electron beam resist, exposure negative electron beam resist, nanoimprinting, laser direct writing, metal deposition, dielectric layer precipitation, stripping or etching methods.

8. The preparation method according to claim 6, characterized in that The deposition method in step (2) includes any one of electron beam evaporation, thermal evaporation, magnetron sputtering or atomic layer deposition.

9. The preparation method according to claim 6, characterized in that The thickness of the metal nanofilm in step (2) is 1-500 nm.

10. The preparation method according to claim 6, characterized in that After the heat treatment in step (2), the metal nanofilm forms single metal nanoparticles inside the three-dimensional dielectric nanostructure.

11. The preparation method according to claim 6, characterized in that The heat treatment in step (2) is carried out under protective gas.

12. The preparation method according to claim 6, characterized in that The holding time of the heat treatment in step (2) is 2 minutes to 5 hours.

13. The preparation method according to claim 6, characterized in that The surface cleaning treatment in step (2) includes: applying a mixture of PDMS and a curing agent on the substrate, then heating and curing it, peeling off the PDMS film to remove the metal nanoparticles on the top of the structure or using a peeling tape to remove the metal nanoparticles on the top of the structure.

14. The preparation method according to claim 13, characterized in that The volume ratio of the PDMS to the curing agent is (5-12):

1.

15. The preparation method according to claim 13, characterized in that The temperature of the heating and curing is 60-85°C.

16. The preparation method according to claim 13, characterized in that The heating and curing time is 0.1-12 hours.

17. Use of the nano-patterned substrate according to any one of claims 1 to 5 in color display.

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