Large-area printing and transferring method for two-dimensional material micro-pattern array

Abstract

Disclosed in the present invention is a large-area printing and transferring method for a two-dimensional material micro-pattern array. The method comprises: preparing a two-dimensional material dispersion; fixedly attaching a mask engraved with a target two-dimensional material micro-pattern onto a porous polymer filter membrane; performing suction filtration and deposition on the two-dimensional material dispersion by means of a vacuum filtration device, so as to obtain a porous polymer filter membrane having the target two-dimensional material micro-pattern; and printing the target two-dimensional material micro-pattern onto a target substrate from the porous polymer filter membrane, and overturning the target substrate to separate same from the porous polymer filter membrane, so as to complete the transferring. The method for printing a two-dimensional material micro-pattern array and transferring same between different substrates as provided by the present invention is easy to operate, has high transfer efficiency and low costs, and can achieve large-area, high-precision, defect-free and patterned two-dimensional material manufacturing of a two-dimensional material micro-pattern array and pollution-free transferring of same between different substrates.

Description

A method for large-area printing and transfer of two-dimensional material micro-pattern arrays Technical Field

[0001] This invention relates to a printing and transfer method, which falls under the field of micro-nano manufacturing technology, and specifically to a method for large-area printing and transfer of two-dimensional material micro-pattern arrays. Background Technology

[0002] With the continuous development and transformation of the materials field, marked by the successful isolation of graphene into a single atomic layer, the dimensions of materials have expanded from the traditional three-dimensional realm to the two-dimensional realm. Two-dimensional materials refer to materials where electrons can move freely only in two dimensions at a non-nanoscale scale. Their carrier migration and heat diffusion are confined within a two-dimensional plane, thus exhibiting many desirable properties and finding wide application in energy storage devices, optoelectronic devices, thermoelectric devices, and other fields. Two-dimensional material micro-nano patterns have high application value and can be used as electrodes for microelectronic devices such as miniature supercapacitors, field-effect transistors, and micro-nano sensors; they can also form electromagnetic metasurfaces composed of arrays of micro-nano functional building blocks, realizing exotic electromagnetic properties not possessed by intrinsic materials and surfaces. Therefore, two-dimensional material micro-nano patterns have broad application prospects in energy storage, microelectronics, and micro-nano optics.

[0003] The manufacturing process of two-dimensional material micro-nano patterns determines their final structure and performance. Commonly used two-dimensional material micro-nano pattern manufacturing processes can be divided into two categories according to their process characteristics: subtractive manufacturing, which first prepares two-dimensional material thin films and then performs patterning, and additive manufacturing, which directly generates two-dimensional material micro-nano patterns.

[0004] Subtractive manufacturing techniques for patterning pre-fabricated two-dimensional material thin films include helium ion beam etching, nanoimprint lithography, and electron beam etching. Helium ion beam etching utilizes helium ions generated by the ionization of the inert gas helium to directly etch two-dimensional materials, enabling the formation of micro / nano patterns with small linewidths. However, the collisions of helium ions inevitably cause vacancies and amorphization damage to the two-dimensional materials, limiting its application in two-dimensional material patterning. Nanoimprint lithography uses an imprint template with the target pattern to apply pressure to an anti-etching layer and a two-dimensional material thin film at high temperature. This pressure is maintained for a period of time, causing deformation of the anti-etching layer. The imprint template is then removed, and the thinner portion of the deformed anti-etching layer and the underlying two-dimensional material thin film are etched. This enables low-cost, large-scale array fabrication of two-dimensional material micropatterns. However, the polymer material used as the anti-etching layer is often difficult to remove, and residual anti-etching layer can contaminate the two-dimensional material. Electron beam lithography first uses an electron beam to etch a resist layer to form a target pattern on the resist layer. Then, oxygen plasma is used to etch the two-dimensional material that is not protected by the resist layer to form the target pattern on the two-dimensional material. This method has high processing precision and can prepare patterns with feature sizes on the nanoscale, but the processing efficiency is low and the resist layer is difficult to completely remove.

[0005] Additive manufacturing technologies for directly generating two-dimensional material micro / nano patterns include self-assembly, plasma-enhanced chemical vapor deposition (PECVD), inkjet printing, and screen printing. Self-assembly utilizes the spontaneous organization and aggregation of structural units such as atoms, molecules, nanomaterials, or other elements through non-covalent bonds or other forces to form ordered and stable structures. Self-assembly is a simple process with high pattern uniformity, but it can only form patterns of specific shapes. Plasma-enhanced chemical vapor deposition controls the shape of the two-dimensional material patterns generated by chemical vapor deposition through artificially designed surface electric field distribution. This method can form two-dimensional material patterns of arbitrary shapes by controlling the electric field, but the pattern precision is low, and the pre-patterned areas require gold plating, making the process complex. Inkjet printing prepares the desired two-dimensional material micro / nano patterns by ejecting ink droplets from the printhead. It can form micro / nano patterns of arbitrary shapes, but inkjet printing efficiency is low, making it difficult to manufacture large-scale micro / nano pattern arrays, and it requires high precision in wetting the printing ink with the substrate. The preparation of micro-nano patterns of two-dimensional materials by screen printing is a simple and low-cost process. However, screen printing requires high fluidity of the paste and pre-patterning of the substrate.

[0006] In summary, in subtractive manufacturing technologies that directly pattern two-dimensional material thin films, nanoimprint lithography and electron beam etching both require processing the target pattern on a resist layer before etching the two-dimensional material itself. This process is complex, and the subsequent removal of the resist layer introduces new impurities. While helium ion beams can directly process the material itself, helium ion impacts can cause damage such as vacancies and amorphization in the two-dimensional material. In additive manufacturing technologies that directly generate micro / nano patterns in two-dimensional materials, plasma-enhanced chemical vapor deposition and screen printing require pre-patterning of the substrate, increasing process complexity and cost. Inkjet printing is limited by its printing speed, making it difficult to achieve efficient production of large-scale micro / nano patterns. Self-assembly methods can only generate specific two-dimensional patterns, limiting their application scope.

[0007] Current methods for transferring two-dimensional (2D) material micro / nano patterns are similar to those for transferring 2D material thin films. The main approach involves coating a support layer onto the surface of the 2D material on a growth substrate, bonding the support layer to the 2D material, and then peeling the 2D material off the growth substrate. Common materials used for the support layer include polymethyl methacrylate (PMMA), polydimethylsiloxane (PDMS), paraffin wax, and thermally release tape. The support layer carrying the 2D material is then transferred to the target substrate. Finally, the 2D material and support material are separated using methods such as substrate etching and electrochemical bubbling, completing the transfer of the 2D material from the growth substrate to the target substrate. However, the removal of the support layer inevitably introduces organic solvents, contaminating the prepared 2D material. Furthermore, the difference in roughness between the growth substrate and the target substrate easily leads to defects such as cracks and wrinkles during the transfer process.

[0008] Current technologies for the fabrication and transfer of two-dimensional material micro-nano patterns include: subtractive manufacturing technology, which involves first fabricating a two-dimensional material thin film and then patterning it; and additive manufacturing technology, which involves directly fabricating two-dimensional material micro-nano patterns. After fabricating the desired two-dimensional material micro-nano pattern, the pattern is transferred through a support layer. However, this method has the following drawbacks: 1) Subtractive manufacturing, which involves first fabricating a two-dimensional material thin film and then patterning it, is complex. Removing the resist layer introduces new impurities, and direct processing without introducing the resist layer can cause damage to the two-dimensional material, such as vacancies and amorphization; 2) Additive manufacturing technology, which directly generates two-dimensional material micro-nano patterns, can only generate patterns of specific shapes or requires pre-patterning of the substrate, resulting in low efficiency and high cost; 3) Defects such as contamination, cracks, and wrinkles are easily generated during the transfer of two-dimensional material micro-nano patterns through a support layer. Summary of the Invention

[0009] To address the problems existing in the background art, this invention provides a method for large-area printing and transfer of two-dimensional material micro-pattern arrays. This method enables high-precision, large-area, defect-free, patterned two-dimensional material manufacturing and transfer onto different substrates.

[0010] The technical solution adopted in this invention is:

[0011] The method for large-area printing and transfer of two-dimensional material micro-pattern arrays of the present invention includes the following steps:

[0012] Step 1) The two-dimensional material nanosheets are uniformly dispersed in a solvent to obtain a two-dimensional material dispersion.

[0013] When the diameter of the two-dimensional material nanosheets is small, methods such as stirring or centrifugation are used to uniformly disperse them in the solvent. When the diameter of the two-dimensional material nanosheets is large, methods such as ultrasonic dispersion or mechanical vibration are used to uniformly disperse them in the solvent. Specific vibration methods are required to ensure uniform material dispersion. For two-dimensional materials that are easily damaged by ultrasound, manual or centrifugal vibration methods can be used to achieve uniform dispersion of the two-dimensional material nanosheets and avoid ultrasonic shattering of the material.

[0014] Step 2) Fix the wetted mask with the micro-pattern of the target two-dimensional material onto the wetted porous polymer filter membrane to ensure that the mask is accurately positioned on the porous polymer filter membrane during the filtration process.

[0015] Step 3) The solvent in the two-dimensional material dispersion is filtered out by a vacuum filtration device. At the same time, the two-dimensional material nanosheets in the two-dimensional material dispersion form the target two-dimensional material micropattern on the porous polymer filter membrane based on the mask, thereby obtaining a porous polymer filter membrane with the target two-dimensional material micropattern in a semi-wet state. It is necessary to control the filtration time to ensure that both the porous polymer filter membrane and the two-dimensional material nanosheets are in a semi-wet state after filtration.

[0016] Step 4) Use a vacuum chuck to remove and fix the semi-wet porous polymer filter membrane with the target two-dimensional material micropattern. After hydrophilic treatment, the smooth target substrate is attached to the porous polymer filter membrane. Under the combined action of external force and vacuum suction of the vacuum chuck, the target two-dimensional material micropattern is printed on the target substrate after a period of time. After flipping the target substrate, it is removed from the porous polymer filter membrane, and the target substrate with the target two-dimensional material micropattern is obtained, completing the large-area, pollution-free transfer of the target two-dimensional material micropattern. The applied external force and the van der Waals force between the target two-dimensional material micropattern and the target substrate work together to achieve the large-area transfer of the target two-dimensional material micropattern array.

[0017] In step 1), the two-dimensional material nanosheets are made of two-dimensional transition metal carbides / nitrides (MXenes), two-dimensional transition metal chalcogenides (TMDs), graphene oxide (GO), graphene, group III-V semiconductor materials, black phosphorus, iron-based metamaterials, three-dimensional topological insulator materials, magnetic topological insulator materials, two-dimensional magnetic materials, or quasi-one-dimensional crystal materials.

[0018] In step 1), the solvent is an alkaline aqueous solution or an organic solvent. The alkaline aqueous solution includes, but is not limited to, water, sodium hydroxide, potassium hydroxide, lithium hydroxide and sodium carbonate, and the organic solvent includes, but is not limited to, methanol, ethanol, isopropanol, acetone, acetonitrile and propylene carbonate.

[0019] In step 1), the mass concentration of the two-dimensional material dispersion is 0.1-1.0 mg / mL. The concentration of the two-dimensional material dispersion should meet the requirement of uniform dispersion of the two-dimensional material nanosheets in the solvent. The concentration of the two-dimensional material dispersion is related to the uniformity of the micro-pattern of the filtered two-dimensional material, and the concentration should be moderate. The amount of the two-dimensional material dispersion is related to the thickness of the micro-pattern of the filtered two-dimensional material. The corresponding volume of the two-dimensional material dispersion is added according to the required thickness.

[0020] In step 2), the mask with the target two-dimensional material micro-pattern is wetted with water to obtain a wetted mask with the target two-dimensional material micro-pattern. The mask is a flexible mask processed by reactive ion etching (RIE) or a rigid mask processed by laser. The flexible mask is made of materials such as pyrene or polyimide, while the rigid mask is made of materials such as silicon wafer, glass, stainless steel or tungsten.

[0021] In step 2), the porous polymer filter membrane is wetted with water to obtain a wetted porous polymer filter membrane; the porous polymer filter membrane is made of nylon 66, nylon 6, polypropylene, polyvinylidene fluoride, polytetrafluoroethylene, polycarbonate, cellulose acetate, nitric acid-acetic acid mixed cellulose, polyethersulfone or polyethylene; the pore size of the porous polymer filter membrane is between 0.1-1 μm.

[0022] The surface modification technology of porous polymer filter membranes can be used to improve their hydrophobicity. Fluorination treatment of the surface of porous polymer filter membranes can make the contact angle of the surface of the porous polymer filter membrane greater than 90°, but the contact angle inside the pores less than 90°.

[0023] In step 3), the vacuum filtration device includes a vacuum pump, a filter dish, a porous sand core, and a flask. A wetted porous polymer filter membrane is applied under vacuum pressure and then fixedly attached to a flat porous sand core. A porous polymer filter membrane and a mask are then fixedly attached sequentially above the porous sand core. The two-dimensional material dispersion is quantitatively transferred to the filter dish using a pipette. The porous sand core is horizontally sealed at the port of the flask. The port of the filter dish is vertically downwards and sealed over the mask. A vacuum pump is used to evacuate the beaker to obtain a vacuum flask. Under the assistance of vacuum pressure, the solvent in the two-dimensional material dispersion is sequentially filtered from the filter dish, mask, porous polymer filter membrane, and porous sand core into the vacuum flask. Two-dimensional material nanosheets form target two-dimensional material micropatterns on the porous polymer filter membrane based on the mask, thereby obtaining a semi-wet porous polymer filter membrane with the target two-dimensional material micropatterns.

[0024] In step 4), the hydrophilic treatment of the smooth target substrate is specifically carried out by using oxygen plasma treatment, ultraviolet light treatment, surfactants, hydrophilic polymer coatings or nanostructure methods, etc. The hydrophilic treatment of the target substrate aims to improve its surface energy.

[0025] The target substrate can be made of materials such as glass, silicon wafer, quartz, plexiglass, metal, polydimethylsiloxane (PDMS), or liquid crystal elastomer. The target substrate can be planar or curved, and the required target substrate can be selected according to the specific application scenario.

[0026] In step 4), the wettability of the porous polymer filter membrane remains unchanged during the printing and transfer process of the target two-dimensional material micropattern on the porous polymer filter membrane.

[0027] In step 4), the feature size of the target two-dimensional material micropattern is between 10 and 1000 μm.

[0028] The method of this invention utilizes vacuum pressure to remove the solvent from the two-dimensional material dispersion, allowing two-dimensional material nanosheets to be uniformly and densely deposited on the filter membrane through the cutout area of ​​the mask, thus achieving the printing of two-dimensional material micropatterns. Taking advantage of the fact that the van der Waals force between the two-dimensional material film and the porous polymer filter membrane is less than the van der Waals force between the two-dimensional material film and the target substrate, the target substrate is attached to the micropattern, and after maintaining pressure for a period of time, it is flipped and removed, thereby achieving the transfer of the two-dimensional material micropattern from the porous polymer filter membrane to the target substrate.

[0029] The beneficial effects of this invention are:

[0030] 1) The present invention proposes a two-dimensional material micro-pattern array printing method. Compared with the traditional subtractive manufacturing process of patterning a pre-prepared two-dimensional material thin film and the additive manufacturing process of directly preparing two-dimensional material micro-patterns, the present invention does not require processing the target pattern on the resist layer first and then etching the two-dimensional material itself, which simplifies the process. Since the resist layer does not need to be removed, no new impurities are introduced. The process does not require direct processing of the material itself, and will not cause damage such as vacancies and amorphization in the two-dimensional material. The method has low cost, high forming efficiency and simple process, and can print large-area two-dimensional material micro-pattern arrays in a short time.

[0031] 2) Traditional additive manufacturing techniques that directly generate two-dimensional material micro-nano patterns can only generate patterns of specific shapes or require pre-patterning of the substrate, which is inefficient and costly. This invention can print different pattern arrays by changing different photomasks, without the need for pre-patterning of the substrate, thus reducing the complexity and cost of the process.

[0032] 3) The two-dimensional material micro-pattern array transfer method proposed in this invention utilizes the principle that the van der Waals force between the two-dimensional material film and the target substrate is higher than that between the two-dimensional material film and the growth substrate. It only requires one transfer from the porous polymer filter membrane to the target substrate. Compared with the traditional film transfer process, which includes two transfers, one from the growth surface to the support layer and the other from the support layer to the target substrate, the process is simple and low in cost.

[0033] 4) Traditional transfer processes require the introduction of a support layer, and the removal of the support layer inevitably introduces organic solvents that contaminate the material. This method achieves transfer by direct contact between the two-dimensional material and the target substrate, eliminating the need for a support layer. This avoids defects such as cracks and wrinkles that may occur during the transfer process due to the difference in roughness between the support layer and the target substrate. Furthermore, there is no need to remove the support layer afterward, so no new impurities are introduced, enabling pollution-free transfer of two-dimensional materials.

[0034] In summary, the method for printing and transferring two-dimensional material micro-pattern arrays on different substrates proposed in this invention is simple to operate, has high transfer efficiency, and low cost. It can realize large-area, high-precision, defect-free, and patterned two-dimensional material micro-pattern array printing and pollution-free transfer on different substrates. Attached Figure Description

[0035] Figure 1 is a diagram of the apparatus and flowchart of the two-dimensional material micro-pattern array printing and transfer method of the present invention. In Figure 1(a), the two-dimensional material micro-pattern array printing apparatus and flowchart of the present invention are shown. Figure 1(b) is a schematic diagram of the removal of the two-dimensional material micro-pattern array mask of the present invention. Figure 1(c) is a diagram of the two-dimensional material micro-pattern array transfer apparatus and flowchart of the present invention.

[0036] Figure 2 is a schematic photograph of the printing and transfer of two different two-dimensional materials, MXene and MoS2, on a porous polymer filter membrane in Embodiment 1 and Comparative Example 1 of the present invention. In Figure 2(a), it is a schematic photograph of the printing of MXene and MoS2 on a porous polymer filter membrane; in Figure 2(b), it is a schematic photograph of the transfer of MXene and MoS2 on a porous polymer filter membrane; and in Figure 2(c), it is a schematic diagram of MXene material before and after printing and transfer through a mask with different numbers of micropatterns.

[0037] Figure 3 is a photograph of the printed and transferred samples of micropatterns with different feature sizes in Embodiment 2 of the present invention, and a magnified photograph of the sample with a feature size of 50 μm. In Figure 3(a), it is a photograph of the printed micropatterns with different feature sizes in Embodiment 2 of the present invention; Figure 3(b), it is a photograph of the transferred samples of micropatterns with different feature sizes in Embodiment 2 of the present invention; Figure 3(c), it is a magnified photograph of the sample with a feature size of 50 μm in Embodiment 2 of the present invention; and Figure 3(d), it is a magnified image of the printed interdigitated electrode with a feature size of 50 μm under a confocal microscope at 5x, 10x, and 20x magnification.

[0038] Figure 4 is a schematic diagram of the micro-pattern after printing and transfer in Embodiment 3 of the present invention. In Figure 4(a), it is a schematic diagram of the MXene micro-pattern after printing and transfer of MXene material in Embodiment 3 of the present invention, and Figure 4(b) is an enlarged schematic diagram of the MXene micro-pattern after printing and transfer of MXene material in Embodiment 3 of the present invention.

[0039] Figure 5 is a diagram showing the transfer effect on different substrates in Embodiment 4 of the present invention;

[0040] In the figure: 1. Two-dimensional material dispersion, 2. Mask, 3-1. Vacuum pump, 3-2. Filter dish, 3-3. Porous polymer filter membrane, 3-4. Porous sand core, 3-5. Vacuum flask, 4. Solvent, 5. Vacuum chuck, 6. Target substrate. Detailed Implementation

[0041] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The accompanying drawings illustrate some embodiments and are intended to explain the embodiments involved in the present invention, but are not limited to such embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Where specific experimental steps or conditions are not specified in the embodiments, they can be performed according to the conventional experimental steps or conditions described in the literature in the art. Where the manufacturers of the reagents or instruments used are not specified, they are all conventional reagent products that can be purchased on the market.

[0042] Specific embodiments of the present invention are as follows:

[0043] Example 1:

[0044] Step 1: Prepare a dispersion of the two-dimensional material: The two-dimensional transition metal carbide / nitride family Ti3C2T... XAn MXene dispersion with a concentration of 0.25 mg / mL was obtained by uniformly dispersing the material in water using ultrasonic oscillation, which meets the requirements for uniform material dispersion and provides good film-forming properties through filtration. Alternatively, a commercially available MXene dispersion can be used for dilution. Take 0.2 mL of a commercially available MXene dispersion with a concentration of 10 mg / mL and add 7.8 mL of solvent to dilute to a concentration of 0.25 mg / mL.

[0045] Step 2: Two-dimensional material micro-pattern printing: As shown in Figure 1(a), which is a reference diagram of the vacuum filtration device, first, the porous polymer filter membrane 3-3 is wetted, and vacuum pressure is applied to make it adhere tightly to the flat porous sand core 3-4 with a porous structure. Then, the mask 2 is wetted. The mask 2 is made of stainless steel material with a thickness of 0.1 mm after laser processing, that is, a rigid material mask is used. The pattern on the mask 2 is an "I" electrode. The mask 2 is tightly attached to the porous polymer filter membrane 3-3 with a pore size of 0.8 μm. The porous polymer filter membrane 3-3 is made of nitric acid-acetic acid mixed cellulose material. The prepared MXene dispersion is quantitatively transferred to the vacuum filter dish 3-2 using a pipette. Then, the vacuum pump 3-1 is used to evacuate the flask to obtain a vacuum flask 3-5. The water in the MXene dispersion is filtered into the vacuum flask 3-5 using air pressure. Ti3C2T X A patterned uniform two-dimensional material film is deposited on the surface of the porous polymer filter membrane 3-3. After removing the mask 2, the desired MXene micropattern can be formed. The minimum feature size of the micropattern is 250 μm, as shown in Figure 2(a).

[0046] Step 3: Improve the hydrophilicity of the target substrate 6: The target substrate 6 is a 30×30mm flat glass. The glass is cleaned with ultrasonic cleaning to remove surface impurities. After drying, the glass is placed in a plasma cleaner. Oxygen plasma is used to impact the glass surface to enhance the hydrophilicity of the glass, which facilitates the subsequent transfer of two-dimensional materials.

[0047] Step 4: Transfer of Two-Dimensional Material Micropatterns: The transfer process is shown in Figure 1(b) and Figure 1(c). After removing the mask 2, a micropattern array is formed. The porous polymer filter membrane 3-3 carrying the semi-wet micropattern array is removed and moved to the transfer platform. The vacuum suction cup 8 on the transfer platform positions and fixes the porous polymer filter membrane 3-3. Then, the hydrophilically treated glass is attached to the micropattern. Under the combined action of external force and vacuum suction, because the van der Waals force between the patterned uniform two-dimensional material film and the glass is stronger than the van der Waals force between the film and the porous polymer filter membrane 3-3, flipping the glass allows the two-dimensional material micropattern to be transferred onto the glass. The transfer result is shown in Figure 2(b). By designing different numbers of micropatterns on the mask 2, large-area array micropattern printing and transfer can be achieved. The results before and after transfer are shown in Figure 2(c).

[0048] Comparative Example 1:

[0049] Step 1: MoS2 in two-dimensional transition metal dichalcogenides (TMDs) is uniformly dispersed in water by ultrasonic vibration to obtain a MoS2 dispersion with a concentration of 1 mg / mL. This satisfies the requirement of uniform material dispersion and has good film-forming properties through filtration. Compared with graphene, which has zero band gap, MoS2 has a band gap and is a novel material that can be used to make transistors. Alternatively, commercially available MoS2 dispersions with a concentration of 1 mg / mL can be purchased directly. This concentration provides good filtration performance and does not require dilution.

[0050] Steps 2-4 are the same as in Example 1. In step 2 of Comparative Example 1, the amount of MoS2 dispersion transferred was 1 mL. The final printed and transferred two-dimensional material micropatterns are shown in Figure 2(a) and Figure 2(b).

[0051] Example 1 and Comparative Example 1 respectively demonstrated the printing and transfer of micropatterns from different types of two-dimensional materials. This method enables the printing and transfer of micropatterns from various two-dimensional materials. Compared to traditional micropattern processing methods, this method is more efficient and lower in cost; it requires only one transfer, eliminating the need for introducing support materials and the organic solutions required for removing support materials, thus simplifying the transfer process and achieving large-area, pollution-free transfer. The size of the porous polymer filter membrane 3-3 can be selected according to actual needs, thereby enabling the printing and transfer of two-dimensional material micropattern arrays of different sizes and array numbers.

[0052] Example 2:

[0053] This embodiment demonstrates the printing and transfer of two-dimensional material micropatterns of the same material with different feature sizes. Steps 1, 3, and 4 are the same as in Embodiment 1. In step 2, a selective hydrophilic treatment is performed on the mask 2 with a feature size of 50 μm before printing to improve the hydrophilicity of the surface and groove areas of the mask 2. The two-dimensional material used for transfer is Ti3C2T from the MXene family. X The experiment used a commercially available MXene dispersion with a concentration of 10 mg / mL. The target substrate 6 was glass, and the mask 2 was a 0.1 mm thick tungsten material mask with laser-processed target micropatterns. The micropatterns on the mask 2 consisted of three interdigitated electrodes of different sizes, with feature sizes of 50 μm, 150 μm, and 250 μm, respectively.

[0054] In step 2 of Example 2, the transferred Ti3C2T XThe dispersion is 1 mL; MXene nanosheets are deposited through mask 2 onto the surface of porous polymer filter membrane 3-3 to form the desired MXene micropattern, as shown in Figure 3(a), with printed patterns of feature sizes of 50 μm, 150 μm and 250 μm from left to right. In step 4 of Example 2, the mask 2 is removed, and the porous polymer filter membrane 3-3 carrying the semi-wet MXene micropattern is transferred to the transfer platform. The vacuum chuck 5 positions the porous polymer filter membrane 3-3 by vacuum adsorption. Then, the hydrophilic surface of the glass is attached to the surface of the MXene micropattern, a certain pressure is applied, and it is held for a period of time. The glass is then flipped over to transfer the MXene micropattern to the glass. The result after the transfer is shown in Figure 3(b), from left to right, which are micropatterns with feature sizes of 50μm, 150μm and 250μm respectively. Figure 3(c) is a magnified view of the interdigitated electrode sample with a feature size of 50μm under a camera. Figure 3(d) is a magnified view of the printed interdigitated electrode with a feature size of 50μm under a confocal microscope at 5x, 10x and 20x magnification respectively.

[0055] Example 2 illustrates that the method of the present invention can realize large-area printing and transfer of two-dimensional material micro-patterns with different feature sizes. Compared with traditional micro-pattern processing methods such as photolithography and laser processing, it has low cost, high efficiency, wide processing size range and can achieve smaller precision. It can realize the printing and transfer of pattern feature sizes from micrometer to millimeter level, and the straightness of the pattern is high.

[0056] Example 3:

[0057] This embodiment uses a Parylene flexible mask, different from the rigid material mask used in Embodiments 1 and 2, for printing and transferring the micro-pattern array. Steps 3 and 4 are the same as in Embodiment 1. In step 2, the mask used is a Parylene flexible mask generated by chemical vapor deposition and patterned by photolithography. The material transferred is Ti3C2T from the MXene family. X The experiment used a commercially available MXene dispersion with a concentration of 10 mg / mL. The target substrate 6 for transfer was a silicon wafer, and the micropattern on the mask 2 was an array of equal signs, with a feature size of 15 μm.

[0058] In step 1 of Example 3, the commercial MXene dispersion was diluted by taking 0.1 mL of the commercial MXene dispersion with a concentration of 10 mg / mL and adding 1.9 mL of solvent to dilute it to a concentration of 0.5 mg / mL.

[0059] In step 2 of Example 3, the transferred Ti3C2T XThe dispersion is 2 mL; MXene nanosheets are deposited through mask 2 onto the surface of porous polymer filter membrane 3-3 to form the desired MXene micropattern array. In step 4 of Example 3, mask 2 is removed, and the porous polymer filter membrane 3-3 carrying the semi-wet MXene micropattern array is transferred to the transfer platform. Vacuum chuck 5 positions the porous polymer filter membrane 3-3 by vacuum adsorption. Then, the hydrophilic side of the silicon wafer is attached to the surface of the MXene micropattern array, a certain pressure is applied, and it is held for a period of time. The silicon wafer is then flipped to realize the transfer of the MXene micropattern array to the silicon wafer. The result after the transfer is shown in Figure 4(a). Figure 4(b) is an enlarged view of the MXene micropattern. The length of one line in a single "equal sign" micropattern is 300 μm and the width is 45 μm. The distance between the two lines is 15 μm.

[0060] Example 3 illustrates that the method of the present invention can use a Perrylin flexible mask to achieve large-area printing and transfer of two-dimensional material micro-patterns with a feature size of 15μm. Compared with a rigid mask, it can achieve lower precision and realize the printing and transfer of more arrays of two-dimensional material micro-patterns.

[0061] Example 4:

[0062] This embodiment demonstrates the printing and transfer of two-dimensional material micropatterns onto target substrates of different materials and shapes. Steps 1-4 are the same as in Embodiment 1. The two-dimensional material used for transfer is Ti3C2T from the MXene family. X Commercially available MXene dispersion with a concentration of 10 mg / mL was used in the experiment. The target substrates 6 for transfer were aluminum foil, glass slides, silicon wafers, PDMS, and glass spheres, respectively. The mask 2 was made of laser-processed stainless steel with a thickness of 0.1 mm, and the mask pattern was an "I" shaped electrode with a minimum feature size of 250 μm.

[0063] In step 2 of Example 3, the transferred Ti3C2T X The dispersion was 1 mL. In step 4 of Example 3, the mask 2 was removed, and the porous polymer filter membrane 3-3 carrying the semi-wet MXene micropattern was transferred to the transfer platform. For the planar target substrate 6, the hydrophilic side of the target substrate 6 was attached to the surface of the MXene micropattern, a certain pressure was applied, and it was held for a period of time. The target substrate 6 was then flipped over to achieve the transfer of the MXene micropattern to the planar target substrate 6. For the curved target substrate 6, the porous polymer filter membrane 3-3 was attached to the target substrate 6, an external force was applied and pressed, and after a period of time, the porous polymer filter membrane 3-3 was quickly peeled off to achieve the transfer of the MXene micropattern to the curved target substrate 6. The transfer results on different target substrates are shown in Figure 5.

[0064] As can be seen from Example 3, the method of the present invention can transfer two-dimensional material micro-patterns to target substrates 6 of different shapes and materials. Compared with the traditional transfer method that requires the introduction of a support layer, only one transfer is required, and the transfer process will not introduce organic polluting materials. It has the characteristics of high precision, large area, and pollution-free transfer, and can realize the manufacturing of patterned two-dimensional materials and the transfer on different substrates.

Claims

1. A method for large-area printing and transfer of two-dimensional material micro-pattern arrays, characterized in that, Includes the following steps: Step 1) The two-dimensional material nanosheets are uniformly dispersed in solvent (4) to obtain a two-dimensional material dispersion (1); Step 2) Fix the wetted mask (2) with the micro-pattern of the target two-dimensional material onto the wetted porous polymer filter membrane (3-3); Step 3) The solvent (4) in the two-dimensional material dispersion (1) is filtered out by vacuum filtration device. At the same time, the two-dimensional material nanosheets in the two-dimensional material dispersion (1) form the target two-dimensional material micro-pattern on the porous polymer filter membrane (3-3) based on the mask (2), thereby obtaining a porous polymer filter membrane (3-3) with the target two-dimensional material micro-pattern in a semi-wet state. Step 4) Use a vacuum chuck (8) to remove and fix the semi-wet porous polymer filter membrane (3-3) with the target two-dimensional material micro-pattern. After hydrophilic treatment, the target substrate (6) is attached to the porous polymer filter membrane (3-3). Under the combined action of external force and vacuum suction of the vacuum chuck (8), the target two-dimensional material micro-pattern is printed on the target substrate (6). After flipping the target substrate (6) off the porous polymer filter membrane (3-3), the target substrate (6) with the target two-dimensional material micro-pattern is obtained, and the transfer of the target two-dimensional material micro-pattern is completed.

2. The method for large-area printing and transfer of two-dimensional material micro-pattern arrays according to claim 1, characterized in that: In step 1), the two-dimensional material nanosheets are made of two-dimensional transition metal carbides / nitrides (MXenes), two-dimensional transition metal chalcogenides (TMDs), group III-V semiconductor materials, black phosphorus, three-dimensional topological insulator materials, magnetic topological insulator materials, two-dimensional magnetic materials, or quasi-one-dimensional crystal materials.

3. The method for large-area printing and transfer of two-dimensional material micro-pattern arrays according to claim 1, characterized in that: In step 1), the solvent (4) is an alkaline aqueous solution or an organic solvent. The alkaline aqueous solution includes water, sodium hydroxide, potassium hydroxide, lithium hydroxide and sodium carbonate, and the organic solvent includes methanol, ethanol, isopropanol, acetone, acetonitrile and propylene carbonate.

4. The method for large-area printing and transfer of two-dimensional material micro-pattern arrays according to claim 1, characterized in that: In step 1), the mass concentration of the two-dimensional material dispersion (1) is 0.1-1.0 mg / mL.

5. The method for large-area printing and transfer of two-dimensional material micro-pattern arrays according to claim 1, characterized in that: In step 2), the mask (2) with the micro-pattern of the target two-dimensional material is wetted with water to obtain a wetted mask (2) with the micro-pattern of the target two-dimensional material; the mask (2) is a flexible mask processed by reactive ion etching (RIE) or a rigid mask processed by laser. The flexible mask is made of pyrene or polyimide, and the rigid mask is made of silicon wafer, glass, stainless steel or tungsten.

6. The method for large-area printing and transfer of two-dimensional material micro-pattern arrays according to claim 1, characterized in that: In step 2), the porous polymer filter membrane (3-3) is wetted with water to obtain a wetted porous polymer filter membrane (3-3); the porous polymer filter membrane (3-3) is made of nylon 66, nylon 6, polypropylene, polyvinylidene fluoride, polytetrafluoroethylene, polycarbonate, cellulose acetate, nitric acid-acetic acid mixed cellulose, polyethersulfone or polyethylene; the pore size of the porous polymer filter membrane (3-3) is between 0.1-1 μm.

7. The method for large-area printing and transfer of two-dimensional material micro-pattern arrays according to claim 1, characterized in that: In step 3), the vacuum filtration apparatus includes a vacuum pump (3-1), a filter dish (3-2), a porous sand core (3-4), and a flask. A moistened porous polymer filter membrane (3-3) is fixedly attached to the porous sand core (3-4). The two-dimensional material dispersion (1) is transferred to the filter dish (3-2). The porous sand core (3-4) is horizontally sealed over the port of the flask. The port of the filter dish (3-2) is vertically downwards and sealed over the mask plate (2). The vacuum pump (3-1) is then used. 1) Vacuum the beaker to obtain a vacuum flask (3-5). The solvent in the two-dimensional material dispersion (1) is sequentially filtered from the filter dish (3-2), the mask (2), the porous polymer filter membrane (3-3), and the porous sand core (3-4) into the vacuum flask (3-5). The two-dimensional material nanosheets form the target two-dimensional material micropattern on the porous polymer filter membrane (3-3) based on the mask (2), thereby obtaining a porous polymer filter membrane (3-3) with the target two-dimensional material micropattern in a semi-wet state.

8. The method for large-area printing and transfer of two-dimensional material micro-pattern arrays according to claim 1, characterized in that: In step 4), the target substrate (6) is hydrophilically treated specifically by using oxygen plasma treatment, ultraviolet light treatment, surfactant, hydrophilic polymer coating or nanostructure method.

9. The method for large-area printing and transfer of two-dimensional material micro-pattern arrays according to claim 1, characterized in that: In step 4), the wettability of the porous polymer filter membrane (3-3) remains unchanged during the printing and transfer process of the target two-dimensional material micropattern on the porous polymer filter membrane (3-3).

10. The method for large-area printing and transfer of two-dimensional material micro-pattern arrays according to claim 1, characterized in that: In step 4), the feature size of the target two-dimensional material micropattern is between 10 and 1000 μm.

Images