Preparation method of material with plasmon array and material

Abstract

The invention discloses a preparation method of a material with a plasmon array and the material. The method comprises the steps that based on a preset nickel female template, imprinting is carried out on a pretreated first original metal sheet; performing anodic oxidation on the first surface of the first original metal sheet to prepare an initial mask plate with an anodic oxidation layer; performing reprocessing on the initial mask plate so as to remove redundant materials on the first original metal sheet under the condition of protecting the anodic oxide layer, thereby obtaining the mask plate; and on the basis of a mask plate, imprinting is performed on the preprocessed second original metal sheet, and the material with the plasmon array is prepared. The material with the array period distance equivalent to the resonance wavelength and coupled with the Bloch wave can be prepared in a secondary imprinting mode, it can be guaranteed that the uniformity and stability of the photon local area are improved under resonance, in addition, the material can inhibit radiation damping through surface plasmon resonance, photons are strongly localized at the nanoscale, and the performance of the material is improved. Therefore, the interaction between the light and the substance is enhanced.

Description

Technical Field

[0001] This application relates to a method for preparing a material with a plasmonic array and the material having a plasmonic array, belonging to the field of nanomaterials technology. Background Technology

[0002] Currently, the phenomenon of surface plasmon resonance is widely used in micro-devices such as nanolasers and nanosensors. This phenomenon is characterized by the oscillation of free electrons on the metal surface, which enables the free electrons to couple with incident photons to form surface plasmon polaritons, thereby generating a significantly enhanced electromagnetic field at the resonance wavelength.

[0003] However, due to the inherently large ohmic loss of metallic materials, the spectral linewidth of surface plasmons is large, which in turn leads to a decrease in the quality factor of surface plasmons, thus limiting the application scenarios of surface plasmon resonance. Summary of the Invention

[0004] This application proposes a method for preparing a material with a plasmonic array and the material having a plasmonic array.

[0005] The method for preparing the material with plasmon array in the embodiments of this application includes the following steps: Based on a preset nickel master template, an imprint is performed on the pre-treated first raw metal sheet to form the original surface structure shape on the first surface of the first raw metal sheet; Anodizing is performed on the first surface of the first original metal sheet to obtain an initial mask with an anodized layer based on the first original metal sheet; The initial mask is further processed to remove excess material from the first original metal sheet while protecting the anodized layer, to obtain the mask. Based on the mask, an imprint is performed on the pre-treated second original metal sheet to form a target surface structure shape on the target surface of the second original metal sheet, thereby obtaining the material with a plasmonic array, wherein the target surface structure shape has a preset array period distance, which is 400nm or 600nm.

[0006] In some embodiments, the pretreatment method for the first raw metal sheet includes: Cut the pre-selected raw aluminum sheet according to the preset size, and clean the cut raw aluminum sheet using a preset organic solvent and a preset inorganic solvent within a first preset time range; Using a pre-selected lead plate as the cathode and the cut raw aluminum sheet as the anode, electrochemical polishing is performed in a pre-prepared polishing agent environment to obtain the first original metal sheet.

[0007] In some embodiments, the method of using a pre-selected lead plate as the cathode and a cut aluminum sheet as the anode, and performing electrochemical polishing in a pre-prepared polishing agent environment to obtain the first original metal sheet, includes: Using a pre-selected lead plate as the cathode and the cut raw aluminum sheet as the anode, electrochemical polishing is performed under the conditions of the polishing agent environment, a preset first reaction voltage, and an ice-water bath, and the execution time is within a second time range to obtain a polished metal sheet. The polishing agent includes perchloric acid and ethanol in a preset ratio, and the second time range is determined according to the roughness of the raw aluminum sheet. The polished metal sheet is cleaned sequentially using a preset inorganic solvent and a preset organic solvent to obtain the first original metal sheet.

[0008] In some embodiments, the preset ratio of perchloric acid and ethanol is 1:7 by volume, the organic solvent includes ethanol, and the inorganic solvent includes ultrapure water.

[0009] In some embodiments, performing anodizing on the first surface of the first original metal sheet to obtain an initial mask having an anodized layer based on the first original metal sheet includes: Under preset oxidation liquid environment, preset second reaction voltage and preset oxidation temperature conditions, anodizing is performed on the first surface of the first original metal sheet for a duration of a third time range to obtain the initial mask plate, wherein the oxidation liquid, the second reaction voltage and the oxidation temperature vary with the array period distance.

[0010] In some embodiments, when the array period distance is 400 nm, the oxidation liquid includes phosphoric acid, ethylene glycol and water, and the preset ratio of phosphoric acid, ethylene glycol and water is 1:200:400 by volume. The second reaction voltage is 160 V and the oxidation temperature is room temperature. With an array period distance of 600 nm, the oxidation solution is an aqueous solution of citric acid, wherein the molar concentration of citric acid is 0.21~0.22 mol / L, the second reaction voltage is 210 V, and the oxidation temperature is -7 °C.

[0011] In some embodiments, the reprocessing of the initial mask to remove excess material from the first original metal sheet while protecting the anodized layer, to obtain the mask, includes: Under preset conditions of phosphoric acid aqueous solution environment and preset temperature, phosphoric acid pore enlargement is performed on the anodic oxide layer to adjust the structural morphology and structural size of the anodic oxide layer; A filler film is constructed on the anodic oxide layer to form a filler composite oxide layer, wherein the filler film comprises a polymethyl methacrylate film; In a preset metal salt solution environment, the filler composite oxide layer is retained, and the remaining portion of the first original metal sheet other than the filler composite oxide layer is removed. The filler film in the filler composite oxide layer is removed under a preset organic solvent environment to obtain the mask.

[0012] In some embodiments, the preset metal salt solution is a mixed solution of copper chloride, water and dilute hydrochloric acid, wherein the molar concentration of copper chloride is 0.13~0.15 mol / L and the volume ratio of water to dilute hydrochloric acid is 1:1.

[0013] In some embodiments, the imprinting of the pretreated second raw metal sheet based on the mask to form a target surface structure shape on the target surface of the second raw metal sheet, thereby obtaining the material with the plasmonic array, includes: Based on the mask, an imprint is performed on the target surface to form the target surface structure shape; The second original metal sheet containing the residual mask is immersed in a chromic acid solution of a predetermined concentration to remove the mask, thereby obtaining the material with the plasmon array. The chromic acid solution is a mixed solution of phosphoric acid aqueous solution, chromium trioxide and water. The phosphoric acid aqueous solution has a mass percentage of 5% and a volume percentage of 4.35% to 4.55% of the total volume of the chromic acid solution. The molar concentration of chromium trioxide in the chromic acid solution is 0.165 to 0.170 mol / L.

[0014] The material with a plasmon array in this application embodiment is prepared according to the preparation method of the material with a plasmon array as described in the above embodiment.

[0015] The beneficial effects of this application are as follows: The preparation method in the embodiments of this application can prepare a material with a plasmonic array that has the same or similar surface structure shape as the master template and whose array period distance is comparable to the resonance wavelength, thereby achieving coupling with Bloch waves, by first manufacturing a mask through a secondary imprinting process and then further performing imprinting on the mask. This ensures that the above material can reduce energy scattering and improve the stability and uniformity of photon localization in the surface plasmonic resonance mode. In addition, the prepared material can suppress radiation damping by using surface plasmonic resonance, so that photons are strongly localized at the nanoscale, thereby enhancing the interaction between light and matter. Attached Figure Description

[0016] Figure 1 This is one of the flowcharts illustrating the preparation method of a material with a plasmonic array in the embodiments of this application; Figure 2 This is a second schematic flowchart of a method for preparing a material with a plasmonic array in an embodiment of this application; Figure 3 This is the third schematic flowchart of the method for preparing materials with plasmon arrays in the embodiments of this application; Figure 4 This is the fourth flowchart illustrating the preparation method of a material with a plasmonic array in the embodiments of this application; Figure 5 This is the fifth flowchart illustrating the preparation method of a material with a plasmonic array in the embodiments of this application. Detailed Implementation

[0017] Please see Figure 1 The method for preparing the material with plasmon array in the embodiments of this application includes the following steps: Step 01: Based on the preset nickel master template, imprinting is performed on the pre-treated first original metal sheet to form the original surface structure shape on the first surface of the first original metal sheet.

[0018] Specifically, the fabrication of materials with plasmon arrays generally involves replicating the surface structure of a pre-defined master template onto a target material, thereby forming a material with a plasmon array. The replication of the surface structure relies primarily on an imprinting process between materials, supplemented by chemical treatment. This imprinting process typically employs a two-stage imprinting method. The first imprinting uses the master template to create a mask, the surface structure of which is complementary to that of the master template. The second imprinting uses this newly created mask to create the material with the plasmon array. The resulting material has a surface structure (i.e., the plasmon array) that is complementary to that of the mask, meaning it shares the same or similar surface structure as the master template.

[0019] Therefore, for example, the first step is to prepare the imprinting mask. This requires selecting a master template and the corresponding imprinting material (i.e., the first original metal sheet). Regarding the selection of the master template material, it typically needs to possess properties such as high hardness, high tensile strength, low coefficient of thermal expansion, a smooth surface for easy processing, and strong corrosion resistance. If the strength and hardness of the master template material are insufficient, it may not be able to effectively shape the carrier material during the imprinting process, thus affecting the final imprinting effect. Among many metals, nickel has a unique advantage in constructing micro / nano structures. Diverse and stable micro / nano structures can be constructed on its surface through deposition or electrochemical methods. The controllability and ease of operation in this construction process are significant. Therefore, for example, a nickel-based master template is selected. Considering the difficulty of imprinting, the hardness and strength of the first original metal sheet should be lower than that of the master template.

[0020] Based on the selection of a first original metal sheet, the imprinting of the first original metal sheet based on the master template can be performed using the currently relevant nanoimprinting technology. For example, based on the selected nickel master template, imprinting is performed on the first surface of the first original metal sheet at a pressure of 7~9MPa at room temperature for 2 minutes, thereby forming an original surface structure shape on the first surface of the first original metal sheet that is complementary to the structural shape of the master template.

[0021] In some implementations, please refer to Figure 2 The first original metal sheet and its processing methods include: Step 001: Cut the pre-selected raw aluminum sheet according to the preset size, and clean the cut raw aluminum sheet with a preset organic solvent and a preset inorganic solvent within a first preset time range; Step 002: Using a pre-selected lead plate as the cathode and a cut aluminum sheet as the anode, perform electrochemical polishing in a pre-prepared polishing agent environment to obtain the first original metal sheet.

[0022] Specifically, based on the above embodiments, the preparation process of the first original metal sheet can be referred to the following example.

[0023] For example, considering the performance requirements of the mask itself, aluminum can be selected as the material for the first raw metal sheet. First, circular or other shaped aluminum sheets are cut from the raw aluminum sheet according to a preset size. The preset size and shape depend on the actual imprinting requirements; for example, circular aluminum sheets with a diameter of approximately 2 cm can be cut, or square aluminum sheets with a diagonal of approximately 2 cm can be cut, etc. Next, the surface of the cut aluminum sheets is cleaned. For example, the aluminum sheets can be placed in a deionized water environment and ultrasonically rinsed with an ethanol-water solution to clean the surface of the aluminum sheets, removing oil and other impurities. The duration of the ultrasonic rinsing can be adjusted as needed, generally limited to 10 minutes.

[0024] Next, since the imprinting process requires a smooth and flat surface for the object being imprinted, further surface polishing is necessary for the cleaned aluminum sheet. This is typically achieved through electrochemical polishing. The main method of electrochemical polishing involves using the aluminum sheet to be polished as the anode and a pre-selected metal with weaker metallic properties than aluminum as the cathode. In a polishing agent environment, the anode aluminum sheet undergoes an oxidation reaction using the principle of an electrolytic cell. The rough, protruding parts of the aluminum sheet surface dissolve preferentially due to the higher current density, while a reduction reaction occurs on the cathode metal sheet surface, thus achieving electrochemical polishing of the aluminum sheet surface. The cathode metal can be selected based on specific requirements; lead can be used as an example. After polishing, the first raw metal sheet is obtained and can be used for the first imprinting process.

[0025] In some implementations, please refer to Figure 3 Step 002 further includes: Step 0021: Using a pre-selected lead plate as the cathode and a cut aluminum sheet as the anode, electrochemical polishing is performed under polishing agent conditions, a preset first reaction voltage, and an ice-water bath, with the execution time being within the second time range, to obtain a polished metal sheet. The polishing agent includes a pre-mixed ratio of perchloric acid and ethanol, and the second time range is determined according to the roughness of the raw aluminum sheet. Step 0022: Clean the polished metal sheet by sequentially using a preset inorganic solvent and a preset organic solvent to obtain the first original metal sheet.

[0026] In some embodiments, the preset ratio of perchloric acid and ethanol is 1:7 by volume, the organic solvent includes ethanol, and the inorganic solvent includes ultrapure water.

[0027] Specifically, based on the above embodiments, for the specific implementation of electrochemical polishing, in some examples, a lead plate is used as the cathode and an aluminum sheet obtained after cutting and rinsing is used as the anode. An electrolytic cell is constructed in a liquid environment of polishing agent, while controlling the voltage, temperature conditions, and reaction time during the electrolytic cell reaction process. Generally, the reaction voltage of the electrolytic cell is controlled at around 30V, and the temperature is controlled at around 0℃. This temperature condition can be achieved by using an ice-water bath. The reaction time is controlled at around 5 minutes. The specific control of the reaction time generally depends on the degree of polishing of the aluminum sheet surface. The above reaction time is only an example. As for the selection of polishing agent, from a principle perspective, it needs to be able to form a viscous passivation film on the aluminum sheet surface, so that the passivation film in the recessed area is thicker, thereby reducing the dissolution rate of the recessed area. Combined with the principle of the electrolytic cell, the dissolution rate of the protruding area is faster, ultimately making the aluminum sheet surface smooth and flat. For example, the polishing agent can be a mixed solution of perchloric acid and ethanol at a volume ratio of 1:7. The strong oxidizing property of perchloric acid is used to form a viscous passivation film on the aluminum sheet surface.

[0028] After electrochemical polishing, for example, before performing the first imprint, the polished aluminum sheet needs to be surface-cleaned to remove residual solids and polishing agent. Generally, surface cleaning consists of two parts: inorganic solvent cleaning and organic solvent cleaning. Inorganic solvent cleaning typically involves ultrasonic cleaning with ultrapure water to peel solids from the aluminum sheet surface and dissolve the polishing agent. Organic solvent cleaning typically involves ultrasonic cleaning with ethanol on the aluminum sheet that has just undergone inorganic solvent cleaning to wash away the ultrapure water containing dissolved polishing agent and solids, thus completing the cleaning process. The execution time for inorganic and organic solvent cleaning can be adjusted according to the actual cleaning effect; for example, it can be set to 7 minutes.

[0029] Please continue reading. Figure 1 The method for preparing the material with plasmon array in this application further includes: Step 02: Perform anodizing on the first surface of the first original metal sheet to obtain an initial mask with an anodized layer based on the first original metal sheet.

[0030] Specifically, based on the above implementation method, after the first imprinting is performed on the first original metal sheet based on the master template, the first surface of the first original metal sheet, which has already formed a surface structure shape, is further anodized to generate an initial mask with an anodized layer, so as to facilitate the subsequent preparation of a mask for a second imprinting based on the initial mask. The purpose of anodizing is: first, to prepare an ordered porous anodized aluminum template, thereby providing a structural mold for the final material with a plasmonic array; second, to use anodizing to generate an anodized aluminum layer on the surface of the first original metal sheet that is thicker, denser, and more firmly bonded to the aluminum substrate than the natural aluminum oxide film, thereby modifying and protecting the surface, avoiding damage to the surface structure shape while ensuring the flatness and uniformity of the mask surface; third, the surface structure shape on the mask can be changed by adjusting the parameters during anodizing to match the performance requirements of the final material in terms of plasmonic lattice resonance.

[0031] In some embodiments, step 02 further includes: Under preset oxidation environment, preset second reaction voltage and preset oxidation temperature conditions, anodizing is performed on the first surface of the first original metal sheet, and the execution time is within the third time range to obtain an initial mask plate, wherein the oxidation solution, the second reaction voltage and the oxidation temperature vary with the array period distance.

[0032] In some embodiments, when the array period distance is 400 nm, the oxidation liquid includes phosphoric acid, ethylene glycol and water, and the preset ratio of phosphoric acid, ethylene glycol and water is 1:200:400 by volume. The second reaction voltage is 160 V and the oxidation temperature is room temperature. With an array period distance of 600 nm, the oxidation solution is an aqueous solution of citric acid, wherein the molar concentration of citric acid is 0.21~0.22 mol / L, the second reaction voltage is 210 V, and the oxidation temperature is -7 °C.

[0033] Specifically, regarding the execution method of anodizing, in some examples, a constant voltage anodizing method can be used to perform anodizing on the first surface of the first original metal sheet under the conditions of the second reaction voltage in the oxidation solution environment and oxidation temperature for 4 hours. After the above oxidation process, a long-range ordered anodized layer (hereinafter referred to as AAO layer) can be obtained.

[0034] Since the main function of the material with plasmon array prepared according to the preparation method in the embodiments of this application is to reduce energy scattering and improve the stability and uniformity of photon localization in the surface plasmon resonance mode, the surface structure shape (i.e., plasmon array) of the above material is generally a shape with a specific array period distance, such as a series of nanoscale pillar arrays spaced at a preset array period distance. Different array period distances have different requirements for the anodic oxide layer, and thus different requirements for the anodic oxide process.

[0035] For example, depending on the practical application of surface plasmon resonance mode, the array period distance generally includes two types: 400 nm and 600 nm. When the array period distance is 400 nm, the oxidation solution typically consists of a mixture of phosphoric acid aqueous solution, ethylene glycol, and water, with a volume ratio of 1:200:400. The externally applied reaction voltage is 160 V, and anodizing is performed at room temperature (20~25℃). When the array period distance is 600 nm, the oxidation solution consists of an aqueous solution of citric acid, with a molar concentration of 0.21~0.22 mol / L. For example, when the solution volume is 600 mL, it contains 25 g of citric acid. The externally applied reaction voltage is 210 V, and anodizing is performed at -7℃. In this way, different anodizing methods can be used to generate initial masks with different surface structure shapes, thereby enabling materials with plasmon arrays prepared by performing a second imprinting on masks based on the initial masks to have different array period distances, in order to adapt to different application scenarios.

[0036] Please continue reading. Figure 1 The method for preparing the material with plasmon array in the embodiments of this application further includes: Step 03: Perform reprocessing on the initial mask to remove excess material from the first original metal sheet while protecting the anodized layer, to obtain the mask.

[0037] Specifically, based on the above embodiments, when anodizing is performed to form an AAO layer on the first original metal sheet to obtain an initial mask, for example, regarding the morphology of the AAO layer on the initial mask, since the requirements for the above morphology in actual applications may not be directly met by the anodizing process, and in addition to the AAO layer, there is also an aluminum substrate on the initial mask, the presence of which may have a certain negative impact on the subsequent secondary imprinting process using the mask, after the AAO layer is formed by anodizing, it is necessary to further reprocess the initial mask. On the one hand, it is necessary to protect the AAO layer and modify its morphology as needed; on the other hand, it is necessary to remove the excess aluminum substrate to form a finished mask so that it can be used for subsequent secondary imprinting.

[0038] Therefore, in some implementations, please refer to Figure 4 Step 03 further includes: Step 031: Under the conditions of a preset phosphoric acid aqueous solution environment and a preset temperature, phosphoric acid pore enlargement is performed on the anodic oxide layer to adjust the structural morphology and structural size of the anodic oxide layer; Step 032: Construct a filler film on the anodic oxide layer to form a filler composite oxide layer. The filler film includes polymethyl methacrylate film; Step 033: In a preset metal salt solution environment, retain the filler composite oxide layer and remove the remaining part of the first original metal sheet other than the filler composite oxide layer; Step 034: Remove the filler film from the filler composite oxide layer in a preset organic solvent environment to obtain a mask.

[0039] Furthermore, in some embodiments, the preset metal salt solution is a mixed solution of copper chloride, water, and dilute hydrochloric acid, wherein the molar concentration of copper chloride is 0.13~0.15 mol / L, and the volume ratio of water to dilute hydrochloric acid is 1:1.

[0040] Specifically, based on the above implementation method, for the reprocessing of the initial mask, the AAO layer can first be subjected to phosphoric acid via etching using a phosphoric acid aqueous solution. During the via etching process, the morphology and dimensions of the complementary shapes of the AAO layer can be adjusted by controlling the via etching time, thereby directly adjusting the morphology and dimensions of the structure on the mask derived from the AAO layer. For example, a 5% (w / w) phosphoric acid aqueous solution is placed in a beaker and heated to 55°C in a water bath. The initial mask is then immersed in the heated phosphoric acid aqueous solution for phosphoric acid via etching, thereby changing the morphology of the AAO layer. The specific processing time depends on the actual morphology requirements.

[0041] Based on the above example, the AAO layer after aperture enlargement and trimming is the mask portion obtained after the first imprinting. Next, the excess aluminum substrate portion on the initial mask, excluding the AAO layer, needs to be removed. During removal, the AAO layer needs to be protected. Therefore, in some examples, polymethyl methacrylate (PMMA) is spin-coated onto the side of the AAO layer with its surface structure shape, achieving a certain thickness. After spin-coating, the entire initial mask is dried in a 60°C oven, allowing the PMMA and AAO to form a filler composite oxide layer. At this point, the filler composite oxide layer and the remaining aluminum substrate on the initial mask remain integrated. Next, the aluminum substrate portion on the initial mask, excluding the filler composite oxide layer, is removed. Based on the above example, the substrate portion other than the filler composite oxide layer is elemental aluminum, which can be achieved by a displacement reaction between aluminum and an aqueous solution of a metal salt with weaker metallic properties than aluminum. For example, a copper chloride solution can be used to react with the aluminum substrate on the carrier material, excluding the filler composite oxide layer, to induce a displacement reaction. During the displacement reaction, the reaction can be maintained by stirring constantly and promptly peeling off the copper precipitates from the aluminum substrate surface. Ultimately, all the remaining aluminum substrate on the carrier material can be removed, leaving only the filler composite oxide layer. The main component of the AAO layer is aluminum oxide, which hardly reacts with the copper chloride solution. Therefore, after removing the aluminum substrate, only appropriate rinsing with ultrapure water is needed to wash away the copper chloride solution. The copper chloride solution is generally a mixture of copper chloride, water, and dilute hydrochloric acid, with a copper chloride concentration of 0.13~0.15 mol / L and a water to dilute hydrochloric acid volume ratio of 1:1. For example, 3.4 g of copper chloride can be dissolved in 100 mL of water and 100 mL of dilute hydrochloric acid of a predetermined concentration to form an acidic or neutral copper chloride solution.

[0042] After removing the aluminum substrate, leaving only the filler composite oxide layer, the PMMA layer simply needs to be peeled off from the AAO layer. The remaining AAO layer after peeling is the mask that can be used for the second imprinting. The PMMA layer can be removed by dissolving it with organic solvents such as acetone or dichloromethane. After dissolution, the remaining AAO layer is transferred from the organic solvent and rinsed successively with ethanol and ultrapure water to obtain the aforementioned mask.

[0043] Please continue reading. Figure 1 The method for preparing the material with plasmon array in the embodiments of this application includes the following steps: Step 04: Based on the mask, perform imprinting on the pretreated second original metal sheet to form the target surface structure shape on the target surface of the second original metal sheet, thereby obtaining a material with a plasmonic array. The target surface structure shape has a preset array period distance, which is 400nm or 600nm.

[0044] Specifically, based on the above embodiments, after the mask is prepared by the first imprinting, the prepared mask can be used to perform a second imprinting on a new raw material metal sheet (corresponding to the second original metal sheet), thereby copying the surface structure shape on the master template onto the new raw material metal sheet, completing the preparation of the material with a plasmon array. The second original metal sheet is also an aluminum sheet, and its preparation process is the same as that of the first original metal sheet, as detailed in the above embodiments.

[0045] Further, please refer to Figure 5 In some implementations, step 04 specifically includes: Step 041: Based on the mask, perform imprinting on the target surface to form the target surface structure shape; Step 042: Immerse the second original metal sheet with the remaining mask in a chromic acid solution of a preset concentration to remove the mask and obtain a material with a plasmonic array. The chromic acid solution is a mixture of phosphoric acid aqueous solution, chromium trioxide and water. The phosphoric acid aqueous solution contains 5% phosphoric acid by mass and accounts for 4.35% to 4.55% of the total volume of the chromic acid solution. The molar concentration of chromium trioxide in the chromic acid solution is 0.165 to 0.170 mol / L.

[0046] Specifically, the second imprinting is performed by first using a mask as a base and then performing the second imprinting on the target surface of the second original metal sheet in a manner similar to the first imprinting. For example, the side of the mask with the surface structure shape is attached to the target surface of the second original metal sheet, and the imprinting is performed on the target surface at a pressure of 7~9MPa at room temperature for 2 minutes, thereby forming a target surface structure shape on the target surface, wherein the target surface structure shape is the same as or similar to the surface structure shape of the master template.

[0047] After imprinting on the second original metal sheet using a mask, the mask can be removed from the second original metal sheet depending on the actual situation. After removing the mask from the second original metal sheet, a material with a plasmonic array is obtained.

[0048] Specifically, regarding the method of removing the mask, a chemical approach can be used to select a substance that dissolves and removes the mask without affecting or minimally affecting the second original metal sheet. In some examples, a chromic acid solution of a preset concentration can be used to treat the second original metal sheet containing the mask residue. As shown in the above example, the mask is derived from anodized aluminum oxide (AAO), while the second original metal sheet is an aluminum sheet or plate. Since chromic acid is a strong oxidizing acid, in the chromic acid solution environment, the surface of the second original metal sheet will rapidly passivate, forming a dense alumina layer. The alumina layer has a regular atomic arrangement and low porosity, making it difficult for chromic acid to react chemically with the alumina layer. Ultimately, this prevents the elemental aluminum in the second original metal sheet from reacting with chromic acid. However, anodized aluminum oxide has a loose, porous, ordered structure with numerous channels and surface defects, allowing it to react and dissolve rapidly in the chromic acid solution. Based on this principle, chromic acid can specifically remove the mask. However, it is important to control the concentration of the chromic acid solution. If the concentration of chromic acid is too high, it will increase the threat to the alumina layer formed by passivation, and the target surface structure shape on the second original metal sheet may not be able to maintain its shape. If the concentration of chromic acid is too low, it may lead to incomplete removal of the mask and reduce the preparation efficiency, ultimately affecting the formation of the plasmon array on the material.

[0049] Therefore, for example, the chromic acid solution can be a mixture of phosphoric acid aqueous solution, chromium trioxide, and water, wherein the mass percentage of phosphoric acid in the phosphoric acid aqueous solution is 5%, the volume percentage of the phosphoric acid aqueous solution in the total chromic acid solution is 4.35%~4.55%, and the molar concentration of chromium trioxide in the chromic acid solution is 0.165~0.170 mol / L. For example, 22.715 mL of a 5% phosphoric acid aqueous solution is mixed with 500 mL of water, and 8.42 g of chromium trioxide is dissolved in the mixture. The mixture is stirred thoroughly at 60°C to form a chromic acid solution. Then, the imprinted mask and the second original metal sheet are immersed together in the above chromic acid solution for 5 minutes. Based on the above principle, the mask with the AAO layer as the main body can be removed, while the second original metal sheet with the target surface structure shape is retained. After removing the residual mask, the residual chromic acid solution and other water-soluble impurities on the second original metal sheet are removed using inorganic materials such as ultrapure water, thus obtaining the material with the above-mentioned plasmon array.

[0050] The material with a plasmon array in this application embodiment is prepared according to the preparation method of the material with a plasmon array in the above embodiment.

[0051] Thus, the method for preparing materials with plasmon arrays in this application embodiment can prepare materials with plasmon arrays by first fabricating a mask through a secondary imprinting process, and then further imprinting the mask. The materials have the same or similar surface structure shape as the master template, and the array period distance is comparable to the resonance wavelength, thereby achieving coupling with Bloch waves. This ensures that the materials with plasmon arrays can reduce energy scattering and improve the stability and uniformity of photon localization in the surface plasmon resonance mode. In addition, the prepared materials with plasmon arrays can suppress radiation damping by utilizing surface plasmon resonance, so that photons are strongly localized at the nanoscale, thereby enhancing the interaction between light and matter.

[0052] The above description is merely a preferred embodiment of this application and is not intended to limit this application in any way. Although this application has disclosed the preferred embodiment as above, it is not intended to limit this application. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the technical solution of this application. Any simple modifications, equivalent substitutions, and improvements made to the above embodiments without departing from the technical solution of this application, based on the technical essence of this application and within the spirit and principles of this application, shall still fall within the protection scope of the technical solution of this application.

Claims

1. A method for preparing a material with a plasmonic array, characterized in that, The method includes: Based on a preset nickel master template, an imprint is performed on the pre-treated first raw metal sheet to form the original surface structure shape on the first surface of the first raw metal sheet; Anodizing is performed on the first surface of the first original metal sheet to obtain an initial mask with an anodized layer based on the first original metal sheet; The initial mask is further processed to remove excess material from the first original metal sheet while protecting the anodized layer, to obtain the mask. Based on the mask, an imprint is performed on the pre-treated second original metal sheet to form a target surface structure shape on the target surface of the second original metal sheet, thereby obtaining the material with a plasmonic array, wherein the target surface structure shape has a preset array period distance, which is 400nm or 600nm.

2. The method according to claim 1, characterized in that, The pretreatment method for the first raw metal sheet includes: Cut the pre-selected raw aluminum sheet according to the preset size, and clean the cut raw aluminum sheet using a preset organic solvent and a preset inorganic solvent within a first preset time range; Using a pre-selected lead plate as the cathode and the cut raw aluminum sheet as the anode, electrochemical polishing is performed in a pre-prepared polishing agent environment to obtain the first original metal sheet.

3. The method according to claim 2, characterized in that, The process of using a pre-selected lead plate as the cathode and the cut raw aluminum sheet as the anode, and performing electrochemical polishing in a pre-prepared polishing agent environment to obtain the first original metal sheet includes: Using a pre-selected lead plate as the cathode and the cut raw aluminum sheet as the anode, electrochemical polishing is performed under the conditions of the polishing agent environment, a preset first reaction voltage, and an ice-water bath, and the execution time is within a second time range to obtain a polished metal sheet. The polishing agent includes perchloric acid and ethanol in a preset ratio, and the second time range is determined according to the roughness of the raw aluminum sheet. The polished metal sheet is cleaned sequentially using a preset inorganic solvent and a preset organic solvent to obtain the first original metal sheet.

4. The method according to claim 3, characterized in that, The preset ratio of perchloric acid and ethanol is 1:7 by volume. The organic solvent includes ethanol, and the inorganic solvent includes ultrapure water.

5. The method according to claim 1, characterized in that, The step of performing anodizing on the first surface of the first original metal sheet to obtain an initial mask with an anodized layer based on the first original metal sheet includes: Under preset oxidation liquid environment, preset second reaction voltage and preset oxidation temperature conditions, anodizing is performed on the first surface of the first original metal sheet for a duration of a third time range to obtain the initial mask plate, wherein the oxidation liquid, the second reaction voltage and the oxidation temperature vary with the array period distance.

6. The method according to claim 5, characterized in that, With an array period distance of 400 nm, the oxidation solution includes phosphoric acid, ethylene glycol, and water, and the preset ratio of phosphoric acid, ethylene glycol, and water is 1:200:400 by volume. The second reaction voltage is 160 V, and the oxidation temperature is room temperature. With an array period distance of 600 nm, the oxidation solution is an aqueous solution of citric acid, wherein the molar concentration of citric acid is 0.21~0.22 mol / L, the second reaction voltage is 210 V, and the oxidation temperature is -7 °C.

7. The method according to claim 1, characterized in that, The reprocessing of the initial mask to remove excess material from the first original metal sheet while protecting the anodized layer, to obtain the mask, includes: Under preset conditions of phosphoric acid aqueous solution environment and preset temperature, phosphoric acid pore enlargement is performed on the anodic oxide layer to adjust the structural morphology and structural size of the anodic oxide layer; A filler film is constructed on the anodic oxide layer to form a filler composite oxide layer, wherein the filler film comprises a polymethyl methacrylate film; In a preset metal salt solution environment, the filler composite oxide layer is retained, and the remaining portion of the first original metal sheet other than the filler composite oxide layer is removed. The filler film in the filler composite oxide layer is removed under a preset organic solvent environment to obtain the mask.

8. The method according to claim 7, characterized in that, The preset metal salt solution is a mixed solution of copper chloride, water and dilute hydrochloric acid, wherein the molar concentration of copper chloride is 0.13~0.15 mol / L and the volume ratio of water to dilute hydrochloric acid is 1:

1.

9. The method according to claim 1, characterized in that, The process of imprinting a pre-treated second raw metal sheet based on the mask to form a target surface structure shape on the target surface of the second raw metal sheet, thereby obtaining the material with the plasmonic array, includes: Based on the mask, an imprint is performed on the target surface to form the target surface structure shape; The second original metal sheet containing the residual mask is immersed in a chromic acid solution of a predetermined concentration to remove the mask, thereby obtaining the material with the plasmon array. The chromic acid solution is a mixed solution of phosphoric acid aqueous solution, chromium trioxide and water. The phosphoric acid aqueous solution has a mass percentage of 5% and a volume percentage of 4.35% to 4.55% of the total volume of the chromic acid solution. The molar concentration of chromium trioxide in the chromic acid solution is 0.165 to 0.170 mol / L.

10. A material having a plasmonic array, characterized in that, The material is prepared according to the method for preparing a material with a plasmonic array as described in any one of claims 1-9.

Images