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

Abstract

The present invention discloses a method for large-area printing and transferring of two-dimensional material micro-pattern arrays. The method includes: preparing a two-dimensional material dispersion; fixedly attaching a mask plate engraved with target two-dimensional material micro-patterns to a porous polymer filter membrane; obtaining a porous polymer filter membrane with target two-dimensional material micro-patterns after suction filtration and deposition of the two-dimensional material dispersion through a vacuum suction filtration device; printing the target two-dimensional material micro-patterns from the porous polymer filter membrane onto a target substrate, and completing the transfer after flipping the target substrate and detaching it from the porous polymer filter membrane. The method for printing and transferring two-dimensional material micro-pattern arrays proposed by the present invention is simple to operate, has high transfer efficiency and low cost, and can achieve large-area, high-precision, defect-free, patterned manufacturing of two-dimensional materials and pollution-free transfer onto different substrates.

Description

Technical Field

[0001] The present invention relates to a printing and transfer method, belonging to the technical field of micro-nano manufacturing, and particularly to a method for large-area printing and transfer of two-dimensional material micro-pattern arrays. Background Art

[0002] With the continuous development and transformation in the field of materials, marked by the successful isolation of single-atom-layer graphene, the dimension of materials has extended from the traditional three-dimensional field to the two-dimensional field. Two-dimensional materials refer to materials in which electrons can move freely only in two non-nano-scale dimensions. Their carrier migration and heat diffusion are restricted within the two-dimensional plane. Therefore, two-dimensional materials exhibit many ideal properties and are widely used in fields such as energy storage devices, optoelectronic devices, and thermoelectric devices. Two-dimensional material micro-nano patterns have high application value. They can be used as electrodes for microelectronic devices such as micro-supercapacitors, field-effect transistors, and micro-nano sensors; they can also form electromagnetic meta-surfaces composed of micro-nano functional element arrays to achieve strange electromagnetic properties that are not possessed by the intrinsic materials and surfaces. Therefore, two-dimensional material micro-nano patterns have broad application prospects in the fields of 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 manufacturing processes for two-dimensional material micro-nano patterns can be classified into two categories according to process characteristics: subtractive manufacturing that first prepares a two-dimensional material thin film and then patterns it, and additive manufacturing that directly generates two-dimensional material micro-nano patterns.

[0004] Subtractive manufacturing techniques for patterning pre-prepared two-dimensional material thin films include helium ion beam etching, nanoimprint lithography, and electron beam lithography. Helium ion beam etching uses ionized inert gas helium to directly etch two-dimensional materials, enabling the formation of micro-nano patterns with a smaller line width. However, vacancies and amorphous damage will inevitably occur in two-dimensional materials under the collision of helium ions, restricting its application in two-dimensional material patterning processing. Nanoimprint lithography uses an imprint template with a target pattern to apply pressure to the anti-etching layer and two-dimensional material thin film at high temperature for a period of time to deform the anti-etching layer. After removing the imprint template, the thinner part of the deformed anti-etching layer and the two-dimensional material thin film below it are etched to achieve low-cost, large-scale array manufacturing of two-dimensional material micro-patterns. However, the polymer material used as the anti-etching layer is usually difficult to remove, and the residual anti-etching layer will contaminate the two-dimensional materials. Electron beam lithography first uses an electron beam to etch the anti-etching layer to form a target pattern on the anti-etching layer, and then uses oxygen plasma to etch the two-dimensional materials not protected by the anti-etching layer to form a target pattern on the two-dimensional materials. This method has high processing accuracy and can prepare patterns with feature sizes in the nanometer scale, but the processing efficiency is low, and the anti-etching layer is also difficult to completely remove.

[0005] Additive manufacturing techniques for directly generating micro-nano patterns of two-dimensional materials include self-assembly, plasma-enhanced chemical vapor deposition, inkjet printing, and screen printing. Self-assembly utilizes structural units such as atoms, molecules, nano-materials, or other elements to spontaneously organize and aggregate through non-covalent bonds or other forces to form an ordered and stable structure. The self-assembly method has a simple process and a high uniformity of the formed patterns, but it can only form patterns with specific shapes. Plasma-enhanced chemical vapor deposition controls the shape of the two-dimensional material patterns generated by chemical vapor deposition by artificially designing the distribution of the surface electric field. This method can form two-dimensional material patterns of any shape by controlling the electric field, but the pattern accuracy is low, and gold plating is required for the pre-patterned area, making the process complex. Inkjet printing prepares the required micro-nano patterns of two-dimensional materials by ejecting ink droplets from a print head, and can form micro-nano patterns of any shape. However, inkjet printing has low efficiency, is difficult to achieve the manufacture of large-scale micro-nano pattern arrays, and has high requirements for the wetting effect of the printing ink and the substrate. The micro-nano patterns of two-dimensional materials are prepared by screen printing, which has a simple process and low cost. However, the screen printing process has high requirements for the fluidity of the slurry and requires pre-patterning treatment of the substrate.

[0006] In summary, in the subtractive manufacturing techniques for directly patterning two-dimensional material films, both nanoimprint lithography and electron beam lithography need to first process the target pattern on the resist layer and then etch the two-dimensional material itself. The process is complex, and the subsequent removal of the resist layer will introduce new impurities. Although the helium ion beam can directly process the material itself, the helium ion impact will cause damage such as vacancies and amorphization in the two-dimensional material. In the additive manufacturing techniques for directly generating micro-nano patterns of two-dimensional materials, plasma-enhanced chemical vapor deposition and screen printing require pre-patterning treatment of the substrate, increasing the complexity and cost of the process; inkjet printing is limited by the printing rate and is difficult to achieve high-efficiency production of large-scale micro-nano patterns; the self-assembly method can only generate specific two-dimensional patterns, and its application range is limited.

[0007] The current existing methods for transferring two-dimensional material micro-nano patterns are the same as those for transferring two-dimensional material thin films. The main idea is as follows: A support layer is coated on the surface of the two-dimensional material on the growth substrate. The support layer is combined with the two-dimensional material, and the two-dimensional material is peeled off from the growth substrate. The materials used as the support layer generally include polymethyl methacrylate (PMMA), polydimethylsiloxane (PDMS), paraffin, thermal release tape, etc.; then the support layer carrying the two-dimensional material is transferred to the target substrate; finally, the two-dimensional material and the support material are separated by methods such as etching the substrate and electrochemical bubbling to complete the transfer of the two-dimensional material from the growth substrate to the target substrate. However, organic solvents will inevitably be introduced during the process of removing the support layer, polluting the prepared two-dimensional materials, and due to the different roughnesses of the growth substrate and the target substrate, defects such as cracks and wrinkles are likely to occur during the transfer process.

[0008] The currently existing two-dimensional material micro-nano pattern preparation and transfer technologies include: subtractive manufacturing technologies that first prepare two-dimensional material thin films and then perform patterning, and additive manufacturing technologies that directly prepare two-dimensional material micro-nano patterns. After preparing the required two-dimensional material micro-nano patterns, the two-dimensional material micro-nano patterns are transferred through a support layer. This method has the following deficiencies: 1) The subtractive manufacturing process of first preparing two-dimensional material thin films and then patterning has complex processes, and the removal of the anti-corrosion layer will introduce new impurities. Direct processing without introducing the anti-corrosion layer will cause damage such as vacancies and amorphization in the two-dimensional materials; 2) The additive manufacturing technology for directly generating two-dimensional material micro-nano patterns can only generate patterns of specific shapes or requires pre-patterning of the substrate, with low efficiency and high cost; 3) Defects such as pollution, cracks, and wrinkles are likely to occur during the process of transferring two-dimensional material micro-nano patterns through the support layer. Summary of the Invention

[0009] To solve the problems existing in the background technology, the present invention provides a method for large-area printing and transfer of two-dimensional material micro-pattern arrays. The method of the present invention can achieve high-precision, large-area, defect-free, and patterned manufacturing of two-dimensional materials and transfer on different substrates.

[0010] The technical solution adopted by the present invention is:

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

[0012] 1) Uniformly disperse two-dimensional material nanosheets 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 centrifugal oscillation are used to uniformly disperse the two-dimensional material nanosheets in the solvent. When the diameter of the two-dimensional material nanosheets is large, methods such as ultrasonic dispersion or mechanical oscillation are used to uniformly disperse the two-dimensional material nanosheets in the solvent. It is necessary to ensure uniform dispersion of the material through a certain oscillation method. For two-dimensional materials that are easily damaged by ultrasound, manual, centrifugal and other oscillation methods can be used to achieve uniform dispersion of the two-dimensional material nanosheets and avoid ultrasonic fragmentation of the material.

[0014] 2) Fix and attach the wetted mask template engraved with the target two-dimensional material micro-pattern on the wetted porous polymer filter membrane to ensure accurate positioning of the mask template on the porous polymer filter membrane during the suction filtration process.

[0015] 3) Filter out the solvent in the two-dimensional material dispersion through a vacuum suction filtration device. At the same time, the two-dimensional material nanosheets in the two-dimensional material dispersion form the target two-dimensional material micro-pattern on the porous polymer filter membrane based on the mask template, so as to obtain a porous polymer filter membrane with the target two-dimensional material micro-pattern in a semi-wet state. It is necessary to control the suction filtration time to ensure that both the porous polymer filter membrane and the two-dimensional material nanosheets are in a semi-wet state after the suction filtration ends.

[0016] 4) Use a vacuum chuck to remove and fix the porous polymer filter membrane with the target two-dimensional material micro-pattern in a semi-wet state. After hydrophilically treating the flat and smooth target substrate, attach it to the porous polymer filter membrane. After a period of time under the combined action of external force assistance and the vacuum suction of the vacuum chuck, print the target two-dimensional material micro-pattern on the target substrate. Flip the target substrate and detach it from the porous polymer filter membrane to obtain the target substrate with the target two-dimensional material micro-pattern, completing the transfer of the large-area and pollution-free target two-dimensional material micro-pattern; the combined action of the applied external force and the van der Waals force between the target two-dimensional material micro-pattern and the target substrate realizes the large-area transfer of the target two-dimensional material micro-pattern array.

[0017] In the described step 1), the material of the two-dimensional material nanosheets is two-dimensional transition metal carbides / nitrides MXenes, two-dimensional transition metal chalcogenides TMDs (Transition Metal Dichalcogenides), graphene oxide GO (graphene oxide), graphene 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 the described 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. The organic solvent includes but is not limited to methanol, ethanol, isopropanol, acetone, acetonitrile and propylene carbonate.

[0019] In the described 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 two-dimensional material nanosheets in the solvent. The concentration of the two-dimensional material dispersion is related to the uniformity of the two-dimensional material micropatterns filtered. The concentration should be appropriate. The amount of the two-dimensional material dispersion is related to the thickness of the two-dimensional material micropatterns filtered. Add the corresponding volume of the two-dimensional material dispersion according to the required thickness.

[0020] In the described step 2), the mask template engraved with the target two-dimensional material micropattern is wetted with water to obtain a wetted mask template engraved with the target two-dimensional material micropattern. The mask template is a flexible mask template processed by using reactive ion etching (RIE) or a rigid mask template processed by using laser. The material of the flexible mask template is parylene or polyimide, and the material of the rigid mask template is silicon wafer, glass, stainless steel, tungsten, etc.

[0021] In the described step 2), the porous polymer filter membrane is wetted with water to obtain a wetted porous polymer filter membrane. The material of the porous polymer filter membrane is nylon 66 material, nylon 6 material, polypropylene, polyvinylidene fluoride, polytetrafluoroethylene, polycarbonate, cellulose acetate, mixed cellulose nitrate-acetate, polyethersulfone or polyethylene. The pore diameter of the porous polymer filter membrane is between 0.1 - 1 μm.

[0022] The porous polymer filter membrane adopts surface modification technology to improve its hydrophobicity. Fluorination treatment of the surface of the porous polymer filter membrane can make the contact angle on the surface of the porous polymer filter membrane greater than 90°, but the contact angle inside the pore channels is less than 90°.

[0023] In the described step 3), the vacuum filtration device includes a vacuum pump, a filtering dish, a porous sand core and a flask. After applying a vacuum pressure to the wetted porous polymer filter membrane, it is fixedly attached to a flat porous sand core. Above the porous sand core, a porous polymer filter membrane and a mask template are fixedly attached in sequence. The two-dimensional material dispersion is quantitatively transferred to the filtering dish with a pipette. The porous sand core is horizontally and hermetically covered at the port of the flask. The port of the filtering dish is vertically downward and hermetically covered on the mask template. Use the vacuum pump to evacuate the beaker to obtain a vacuum flask. The solvent in the two-dimensional material dispersion is sequentially filtered from the filtering dish, the mask template, the porous polymer filter membrane and the porous sand core into the vacuum flask under the assistance of vacuum pressure. The two-dimensional material nanosheets form the target two-dimensional material micropatterns on the porous polymer filter membrane based on the mask template, thereby obtaining a semi-wetted porous polymer filter membrane with the target two-dimensional material micropatterns.

[0024] In the step 4), the treatment of making the flat and smooth target substrate hydrophilic specifically includes using oxygen plasma treatment, ultraviolet light treatment, surfactant, hydrophilic polymer coating, nanostructure method, etc. The purpose of the hydrophilic treatment of the target substrate is to increase its surface energy.

[0025] The materials used for the target substrate are glass, silicon wafer, quartz, plexiglass, metal, polydimethylsiloxane (PDMS) or liquid crystal elastomer; the shape of the target substrate can be planar or curved, and the required target substrate can be selected according to specific application scenarios.

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

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

[0028] The method of the present invention uses a vacuum pressure-assisted method to extract the solvent in the two-dimensional material dispersion liquid, and then the two-dimensional material nanosheets are uniformly and densely deposited on the membrane through the hollowed-out area of the mask template, realizing the printing of the two-dimensional material micropattern; taking advantage of the fact that the van der Waals force between the two-dimensional material thin film and the porous polymer membrane is less than the van der Waals force between the two-dimensional material thin film and the target substrate, the target substrate is attached to the micropattern, and after maintaining pressure for a period of time, it is turned over and removed, realizing the transfer of the two-dimensional material micropattern from the porous polymer membrane to the target substrate.

[0029] The beneficial effects of the present invention are:

[0030] 1) A method for printing a two-dimensional material micropattern array proposed by the present invention, 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 a two-dimensional material micropattern, the present invention does not need to first process the target pattern on the anti-corrosion layer and then etch the two-dimensional material itself, simplifies the process, and does not need to remove the anti-corrosion layer, so no new impurities will be introduced; during the process, there is no need to directly process the material itself, and the two-dimensional material will not be damaged such as vacancies and amorphization. The method has low cost, high forming efficiency and simple process, and can print a large-area two-dimensional material micropattern array in a short time.

[0031] 2) The traditional additive manufacturing technology for directly generating two-dimensional material micro-nano patterns can only generate patterns of specific shapes or requires pre-patterning treatment of the substrate, with low efficiency and high cost. The present invention can realize the printing of different pattern arrays by replacing different mask plates, without the need for pre-patterning treatment of the substrate, reducing the complexity and cost of the process.

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

[0033] 4) The traditional transfer process needs to introduce a support layer, and it is inevitable to introduce organic solvent pollution to the material when removing the support layer. This method realizes the transfer through the direct contact between the two-dimensional material and the target substrate, without the need to introduce a support layer. It will not cause defects such as cracks and wrinkles during the transfer process due to the different roughness of the support layer and the target substrate, nor is it necessary to remove the support layer subsequently. Therefore, no new impurities will be introduced, and pollution-free transfer of two-dimensional materials can be achieved.

[0034] In summary, the method for printing and transferring the two-dimensional material micro-pattern array proposed by the present invention is simple to operate, has high transfer efficiency and low cost, and can achieve large-area, high-precision, defect-free, patterned printing of the two-dimensional material micro-pattern array and pollution-free transfer on different substrates. Description of the Drawings

[0035] Figure 1 is the device and flow chart of the method for printing and transferring the two-dimensional material micro-pattern array of the present invention. Among them, Figure 1 (a) is the device and flow chart of the two-dimensional material micro-pattern array printing device of the present invention, Figure 1 (b) is the schematic diagram of the removal of the mask plate of the two-dimensional material micro-pattern array of the present invention, Figure 1 (c) is the device and flow chart of the two-dimensional material micro-pattern array transfer device of the present invention;

[0036] Figure 2 is the schematic diagram of the printing and transfer photos of two different two-dimensional materials, MXene and MoS 2 on the porous polymer filter membrane in Example 1 and Comparative Example 1 of the present invention. Among them, Figure 2 (a) is the schematic diagram of the printing photo of MXene and MoS 2 on the porous polymer filter membrane, Figure 2 (b) is the schematic diagram of the transfer photo of MXene and MoS 2 on the porous polymer filter membrane, Figure 2 (c) is the schematic diagram before and after the printing and transfer of the MXene material through the mask plate designed with different numbers of micro-patterns;

[0037] Figure 3It is a photograph of the printed and transferred samples of micropatterns with different feature sizes in Example 2 of the present invention and a schematic enlarged photograph of the sample with a feature size of 50 μm. Among them, Figure 3 (a) is a schematic diagram of the printed photograph of the micropatterns with different feature sizes in Example 2 of the present invention, Figure 3 and (b) is a schematic photograph of the transferred samples of the micropatterns with different feature sizes in Example 2 of the present invention, Figure 3 and (c) is a schematic enlarged photograph of the sample with a feature size of 50 μm in Example 2 of the present invention, Figure 3 and (d) is the enlarged views of 5 times, 10 times and 20 times of the printed interdigital electrodes with a feature size of 50 μm under a confocal microscope;

[0038] Figure 4 It is a schematic diagram of the micropatterns after printing and transferring in Example 3 of the present invention. Among them, Figure 4 (a) is a schematic diagram of the MXene micropatterns after printing and transferring the MXene material in Example 3 of the present invention, Figure 4 and (b) is a schematic enlarged diagram of the MXene micropatterns after printing and transferring the MXene material in Example 3 of the present invention;

[0039] Figure 5 It is the transfer effect diagram on different substrates in Example 4 of the present invention;

[0040] In the figure: 1, two-dimensional material dispersion liquid; 2, mask; 3-1, vacuum pump; 3-2, suction filter dish; 3-3, porous polymer filter membrane; 3-4, porous sintered filter; 3-5, vacuum flask; 4, solvent; 5, vacuum chuck; 6, target substrate. Detailed implementation manners

[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, aiming to explain the embodiments involved in the present invention, but not limited to such embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention. For those embodiments where specific experimental steps or conditions are not indicated, the operations or conditions of the conventional experimental steps described in the literature in this field can be followed. For the reagents or instruments whose manufacturers are not indicated, they are all conventional reagent products that can be obtained through market purchase.

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

[0043] Example 1:

[0044] Step 1: Prepare the dispersion liquid of the two-dimensional material: Dissolve Ti in the two-dimensional transition metal carbide / nitride MXene family 3 C2 T X It is uniformly dispersed in water by ultrasonic oscillation to obtain an MXene dispersion with a concentration of 0.25 mg / ml, which can meet the requirement of uniform dispersion of the material and has good filtration and film-forming properties. It is also possible to dilute a commercial MXene dispersion. Take 0.2 ml of a commercial MXene dispersion with a concentration of 10 mg / ml and add 7.8 ml of solvent for dilution to a concentration of 0.25 mg / ml.

[0045] Step 2: Micro-patterning printing of two-dimensional materials: As shown in Figure 1 Figure (a) of, which is a reference diagram of a vacuum filtration device. First, wet the porous polymer filter membrane 3-3, apply a vacuum pressure to make it tightly adhere to the flat porous sand core 3-4 with a porous structure, then wet the mask template 2. The mask template 2 is made of stainless steel with a thickness of 0.1 mm processed by laser, that is, a rigid material mask template. The pattern on the mask template 2 is a "work" electrode. Closely attach the mask template 2 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 a mixed cellulose nitrate-acetate material; quantitatively transfer 1 ml of the prepared MXene dispersion to the filtration dish 3-2 with a pipette, and then use the vacuum pump 3-1 to evacuate the flask to obtain a vacuum flask 3-5. Use the air pressure to filter the water in the MXene dispersion into the vacuum flask 3-5, Ti 3 C 2 T X A patterned and uniform two-dimensional material thin film is deposited on the surface of the porous polymer filter membrane 3-3. Remove the mask template 2 to form the required MXene micro-pattern. The minimum feature size of the micro-pattern is 250 μm, as shown in Figure 2 Figure (a) of.

[0046] Step 3: Improve the hydrophilicity of the target substrate 6: The target substrate 6 uses a 30×30 mm planar glass. Remove the surface impurities of the glass by ultrasonic cleaning, and put the dried glass into a plasma cleaner. Use oxygen plasma to impact the glass surface to enhance the hydrophilicity of the glass, which is convenient for subsequent transfer of two-dimensional materials.

[0047] Step 4: Transfer of two-dimensional material micro-patterns: The transfer process is as shown in Figure 1 Figure (b) of and Figure 1As shown in (c), after removing the mask 2, a micro-pattern array is formed. The porous polymer filter membrane 3-3 carrying the micro-pattern array in a semi-wet state is removed and transferred to the transfer platform. The vacuum chuck 8 on the transfer platform positions and fixes the porous polymer filter membrane 3-3. Then, the glass after hydrophilic treatment is attached to the micro-patterns. Under the combined action of external force assistance and vacuum suction, since the van der Waals force between the patterned two-dimensional material thin film and the glass is stronger than that between the porous polymer filter membrane 3-3, flipping the glass can transfer the two-dimensional material micro-patterns to the glass. The transfer result is as shown in Figure 2 of (b). By designing different numbers of micro-patterns on the mask 2, large-area array micro-pattern printing and transfer can be achieved. Before and after the transfer, it is as shown in Figure 2 of (c).

[0048] Comparative Example 1:

[0049] Step 1: MoS in two-dimensional transition metal chalcogenides (TMDs) is uniformly dispersed in water by ultrasonic vibration to obtain a MoS dispersion with a concentration of 1 mg / ml, which can meet the requirement of uniform material dispersion and has good filtration and film-forming properties. MoS has a bandgap compared with graphene with zero bandgap and is a new type of material that can be used to fabricate transistors. Commercially available MoS dispersion with a concentration of 1 mg / ml can also be directly purchased. This concentration has a good filtration effect and does not require dilution. 2 The dispersion liquid, which can meet the requirement of uniform material dispersion and has good filtration and film-forming properties. MoS 2 Compared with graphene with zero bandgap, it has a bandgap and is a new type of material that can be used to fabricate transistors. Commercially available MoS 2 dispersion with a concentration of 1 mg / ml can also be directly purchased. This concentration has a good filtration effect and does not require dilution. 2 Step 2 - Step 4 are the same as in Example 1. In Step 2 of Comparative Example 1, the transferred MoS dispersion is 1 ml. The finally printed and transferred two-dimensional material micro-patterns are as shown in

[0050] (a) and 2 as shown in (b) of Figure 2 and Figure 2 .

[0051] In Example 1 and Comparative Example 1, micro-pattern printing and transfer of different types of two-dimensional materials are carried out respectively, which can realize the printing and transfer of different two-dimensional material micro-patterns. Compared with the traditional micro-pattern processing method, this method has high efficiency and low cost. Only one transfer is required, without introducing support materials and the organic solutions required for removing support materials, which simplifies the transfer process and realizes large-area and pollution-free transfer. The size of the porous polymer filter membrane 3-3 can be selected according to actual needs, so as to realize the printing transfer of two-dimensional material micro-pattern arrays with different sizes and different array numbers.

[0052] Example 2:

[0053] This embodiment performs the printing and transfer of two-dimensional material micro-patterns of the same material with different feature sizes. Steps 1, 3, and 4 are the same as those in Embodiment 1. In Step 2, the mask template 2 with a feature size of 50 μm needs to be selectively hydrophilized before printing to improve the hydrophilicity of the surface of the mask template 2 and the groove area of the mask template 2. Among them, the two-dimensional material for transfer is Ti in the MXene family 3 C 2 T X . In the experiment, a commercial MXene dispersion with a concentration of 10 mg / ml was used. The target substrate 6 for transfer is glass, and the mask template 2 is a 0.1-mm-thick tungsten material mask template with the target micro-pattern processed by laser. The micro-pattern on the mask template 2 is three interdigital electrodes with different sizes, and the feature sizes are 50 μm, 150 μm, and 250 μm respectively.

[0054] In Step 2 of Embodiment 2, the transferred Ti 3 C 2 T X dispersion is 1 ml; the MXene nanosheets are deposited on the surface of the porous polymer filter membrane 3-3 through the mask template 2 to form the required MXene micro-patterns. As shown in (a) of Figure 3 , from left to right are the printed patterns with feature sizes of 50 μm, 150 μm, and 250 μm respectively. In Step 4 of Embodiment 2, the mask template 2 is removed, and the porous polymer filter membrane 3-3 carrying the semi-wet MXene micro-patterns 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 micro-patterns, a certain pressure is applied, and maintained for a period of time. After the glass is flipped, the transfer of the MXene micro-patterns to the glass can be achieved. The transferred result is shown in (b) of Figure 3 , from left to right are the micro-patterns with feature sizes of 50 μm, 150 μm, and 250 μm respectively. As shown in (c) of Figure 3 , it is an enlarged view of the 50-feature-size interdigital electrode specimen under the camera. As shown in (d) of Figure 3 , from left to right are the enlarged views of the printed 50-μm feature-size interdigital electrodes under the confocal microscope at 5 times, 10 times, and 20 times magnification respectively.

[0055] Embodiment 2 shows that the method of the present invention can achieve 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, a wide processing size range, and can achieve smaller precision, realizing the printing and transfer of pattern feature sizes in the range from micron level to millimeter level, and the straightness of the patterns made is relatively high.

[0056] Embodiment 3:

[0057] In this embodiment, a parylene flexible mask is used instead of the rigid material masks used in Embodiment 1 and Embodiment 2 for printing and transferring the micro-pattern array. Steps 3 and 4 are the same as those in Embodiment 1. In Step 2, the mask used is a parylene flexible mask formed by chemical vapor deposition and patterned by photolithography. Among them, the transferred material is Ti of the MXene family 3 C 2 T X . In the experiment, a commercial MXene dispersion with a concentration of 10 mg / ml was used. The target substrate 6 for transfer is a silicon wafer. The micro-pattern on the mask 2 is an "equal sign" pattern array, and the feature size is 15 μm.

[0058] In Step 1 of Embodiment 3, the commercial MXene dispersion was diluted. 0.1 ml of the commercial MXene dispersion with a concentration of 10 mg / ml was taken and diluted to a concentration of 0.5 mg / ml by adding 1.9 ml of solvent.

[0059] In Step 2 of Embodiment 3, the transferred Ti 3 C 2 T X dispersion was 2 ml; the MXene nanosheets were deposited on the surface of the porous polymer membrane 3-3 through the mask 2 to form the required MXene micro-pattern array. In Step 4 of Embodiment 3, the mask 2 was removed, and the porous polymer membrane 3-3 carrying the semi-wet MXene micro-pattern array was transferred to the transfer platform. The vacuum chuck 5 positioned the porous polymer membrane 3-3 by vacuum adsorption; then the hydrophilic surface of the silicon wafer was attached to the surface of the MXene micro-pattern array, a certain pressure was applied, and maintained for a period of time, and then the silicon wafer was flipped, and the transfer of the MXene micro-pattern array to the silicon wafer could be realized. The result after transfer is as shown in Figure 4 (a) of Figure 4 (b) is an enlarged view of the MXene micro-pattern. The length of a line in a single "equal sign" micro-pattern is 300 μm, the width is 45 μm, and the distance between two lines is 15 μm.

[0060] Embodiment 3 shows that the method of the present invention can use a parylene flexible mask to achieve large-area printing and transfer of two-dimensional material micro-patterns with a feature size of 15 μm, and can achieve a smaller accuracy compared to a rigid mask, and realize the printing and transfer of two-dimensional material micro-patterns with a larger number of arrays.

[0061] Embodiment 4:

[0062] In this embodiment, two-dimensional material micro-pattern printing and transfer are carried out on target substrates of different materials and shapes. Steps 1 - 4 are the same as those in Embodiment 1. Among them, the two-dimensional material for transfer is Ti of the MXene family 3 C2 T X , a 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 beads respectively. The material of the mask template 2 was stainless steel with a thickness of 0.1 mm processed by laser, and the pattern of the mask template was a "worker" character electrode with a minimum feature size of 250 μm.

[0063] In step 2 of Example 3, the transferred Ti 3 C 2 T X dispersion was 1 ml. In step 4 of Example 3, the mask template 2 was removed, and the porous polymer filter membrane 3-3 carrying the formed semi-wet MXene micropattern was transferred to the transfer platform. For the planar target substrate 6, the hydrophilic surface of the target substrate 6 was attached to the surface of the MXene micropattern, a certain pressure was applied, and held for a period of time. Then the target substrate 6 was flipped, and the transfer of the MXene micropattern to the planar target substrate 6 could be achieved; 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 to press, and after holding for a period of time, the porous polymer filter membrane 3-3 was quickly peeled off, and the transfer of the MXene micropattern to the curved target substrate 6 could be achieved. The transfer results on different target substrates are as Figure 5 shown.

[0064] It can be seen from Example 3 that the method of the present invention can achieve the transfer of two-dimensional material micropatterns to target substrates 6 with different shapes and materials. Compared with the traditional transfer method that requires the introduction of a support layer, only one transfer is needed, and no organic pollution materials will be introduced during the transfer process; it has the characteristics of high-precision, large-area, and pollution-free transfer, and can realize the manufacture of patterned two-dimensional materials and transfer on different substrates.

Claims

1. A method for large-area printing and transfer of a two-dimensional material micro-pattern array, characterized in that: The steps include: 1) uniformly dispersing the two-dimensional material nanosheets in a solvent (4) to obtain a two-dimensional material dispersion (1), wherein the solvent (4) is an alkaline aqueous solution or an organic solvent; 2) fixing a wet mask (2) engraved with a target two-dimensional material micro-pattern onto a wet porous polymer filter membrane (3-3); 3) filtering out the solvent (4) in the two-dimensional material dispersion (1) by a vacuum filtration device, and at the same time, the two-dimensional material nanosheets in the two-dimensional material dispersion (1) form a target two-dimensional material micro-pattern on the porous polymer filter membrane (3-3) based on the mask (2), thereby obtaining a semi-wetted porous polymer filter membrane (3-3) with the target two-dimensional material micro-pattern; 4) using a vacuum suction cup (8) to remove and fix the semi-wet porous polymer filter membrane (3-3) with the target two-dimensional material micro-pattern, subjecting the target substrate (6) to hydrophilic treatment and attaching it to the porous polymer filter membrane (3-3), printing the target two-dimensional material micro-pattern on the target substrate (6) with the assistance of an external force and the vacuum suction of the vacuum suction cup (8), flipping the target substrate (6) and separating it from the porous polymer filter membrane (3-3), obtaining the target substrate (6) with the target two-dimensional material micro-pattern, and completing the transfer of the target two-dimensional material micro-pattern; In the step 1), the material used for the two-dimensional material nanosheet is two-dimensional transition metal carbide / nitride MXenes, two-dimensional transition metal chalcogenide TMDs, III-V semiconductor materials, black phosphorus, three-dimensional topological insulator materials, magnetic topological insulator materials, two-dimensional magnetic materials or quasi-one-dimensional crystalline materials; In the step 1), the mass concentration of the two-dimensional material dispersion (1) is 0.1-1.0 mg / mL; The characteristic size of the target 2D material micropattern is between 10-1000 μm; The target substrate is made of glass, silicon wafer, quartz, organic glass, metal, polydimethylsiloxane (PDMS) or liquid crystal elastomer; the target substrate is flat or curved; A surface modification treatment of the porous polymer filter membrane (3-3) to improve hydrophobicity by fluorination makes the contact angle of the surface of the porous polymer filter membrane (3-3) greater than 90° but the contact angle of the inside of the pores less than 90°; After the solvent (4) in the two-dimensional material dispersion (1) is extracted by vacuum pressure assistance, the two-dimensional material nanosheets are uniformly and densely deposited on the porous polymer filter membrane (3-3) through the hollowed-out area of ​​the mask (2) to print the two-dimensional material micro-pattern; the van der Waals force between the target two-dimensional material micro-pattern and the porous polymer filter membrane (3-3) is smaller than the van der Waals force between the target two-dimensional material micro-pattern and the target substrate (6), the target substrate (6) is attached to the target two-dimensional material micro-pattern, and after maintaining pressure for a preset time period, it is flipped and removed, and the target two-dimensional material micro-pattern is transferred from the porous polymer filter membrane (3-3) to the target substrate (6); Before printing, the mask (2) is selectively subjected to hydrophilic treatment to improve the hydrophilicity of the mask (2) surface and the mask (2) groove region.

2. The large-area printing and transfer method of two-dimensional material micro-pattern array according to claim 1, characterized in that: In the step 1), 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.

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

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

5. The large-area printing and transfer method of two-dimensional material micro-pattern array according to claim 1, characterized in that: In the step 3), the vacuum filtration device comprises a vacuum pump (3-1), a filtration dish (3-2), a porous sand core (3-4) and a flask, the wetted 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 filtration dish (3-2), the porous sand core (3-4) is horizontally sealed on the port of the flask, the port of the filtration dish (3-2) is vertically downward and sealed on the mask (2), and the vacuum pump (3-1) is used. ) The beaker is evacuated to obtain a vacuum flask (3-5), and the solvent in the two-dimensional material dispersion (1) is filtered from the filtration 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) in sequence; the two-dimensional material nanosheets form a target two-dimensional material micro-pattern on the porous polymer filter membrane (3-3) based on the mask (2), thereby obtaining a semi-wetted porous polymer filter membrane (3-3) with the target two-dimensional material micro-pattern.

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

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

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