A method for preparing graphene nanoribbons based on a nanowire mask printing process

Abstract

The application discloses a preparation method of graphene nanobelt based on a nanowire mask printing process. The method is composed of electrohydrodynamic printing, plasma etching and ultrasonic peeling technology. First, a polymethyl methacrylate (PMMA) solution is used to form a transferable film on the surface of graphene. Then, ammonium persulfate etching is used to remove the copper foil at the bottom of the graphene. Digital controllable nanowire technology is adopted to accurately print organic polymer nanowires on the surface of the graphene as a mask. Through the reaction ion etching technology, the graphene not covered by the mask is accurately removed. The mask is removed by using the ultrasonic peeling technology, and the one-dimensional graphene nanobelt with a high width-to-length ratio is prepared. By adjusting the key parameters such as the diameter, spacing and etching time of the nanowire mask, the width and spacing distribution of the graphene nanobelt are optimized, and the consistency and controllability of the preparation quality are improved.

Description

Technical fields:

[0001] This invention belongs to the field of electronic devices, and specifically relates to a method for preparing graphene nanoribbons based on nanowire mask printing technology. Background technology:

[0002] In the context of the digital age, the rapid development of artificial intelligence technology is constantly increasing the demand for advanced electronic devices. This trend has promoted the advancement of electronic material properties and manufacturing technologies in the fields of semiconductors and nanomaterials. As a two-dimensional nanomaterial, graphene has been widely studied due to its excellent electronic properties of high carrier mobility. However, its inherent zero bandgap property is a significant drawback in some electronic applications, especially in semiconductor devices such as transistors.

[0003] The introduction of one-dimensional graphene nanoribbon technology offers an effective solution to the above problems. Through the quantum confinement effect induced by size reduction, the band gap of graphene nanoribbons is expanded, giving them the functional properties of semiconductor materials. This property transformation makes the application of graphene in electronic devices, especially in the fabrication of high-performance transistors, possible. However, current methods for preparing graphene nanoribbons typically employ metal nanoparticle etching, carbon nanotube cleaving, and atomic assembly, but these methods generally suffer from complex processes and the inability to precisely define the morphology and size of the graphene nanoribbons, limiting their feasibility for industrial-scale applications. Using one-dimensional masks for ion beam exposure allows for precise control of the width and morphology of graphene nanoribbons. However, existing nanowire mask fabrication techniques still face the challenge of uneven nanowire arrangement and distribution, making custom patterning difficult. The literature "Rational Fabrication of Graphene Nanoribbons Using a Nanowire Etch Mask" (published in the American academic journal *Nano Letters*, 2009, Vol. 9, pp. 2083-2087) reports the use of chemically synthesized nanowires as masks in oxygen plasma etching to prepare graphene nanoribbons. However, nanowire masks prepared by chemical synthesis cannot achieve precise mask pattern design. The patent "A Method for Preparing Graphene Nanoribbons" (CN 110342504A, 2019.10.18) reports a method that manipulates the direction and distance of nanowires using a probe, ultimately arraying the dispersed nanowires. The nanowire array is then used as a mask for etching to obtain a nanoribbon array. However, this method requires manual adjustment of the nanowire mask's direction and position, which is cumbersome and unfavorable for the fabrication of large-scale nanoribbon patterning. Summary of the Invention:

[0004] The purpose of this invention is to address the limitations of current technologies by providing a method for preparing graphene nanoribbons based on nanowire mask printing. This method comprises electrohydrodynamic printing, plasma etching, and ultrasonic exfoliation. First, a transferable thin film is formed on the graphene surface using a polymethyl methacrylate (PMMA) solution. Then, the copper foil at the bottom of the graphene is removed by ammonium persulfate etching. Digitally controlled nanowire technology is used to precisely print organic polymer nanowires onto the graphene surface as a mask. Reactive ion etching is then used to precisely remove the graphene not covered by the mask, and ultrasonic exfoliation is used to remove the mask, resulting in one-dimensional graphene nanoribbons with a high aspect ratio. This invention optimizes the width and spacing distribution of the graphene nanoribbons by meticulously adjusting key parameters such as the diameter, spacing, and etching time of the nanowire mask, thereby improving the consistency and controllability of the fabrication quality.

[0005] The technical solution of this invention is as follows:

[0006] A method for preparing graphene nanoribbons based on nanowire mask printing technology, the process steps of which are as follows:

[0007] (1). Graphene film transfer:

[0008] A copper foil with a graphene film grown on it was attached to a glass slide using isopropanol. The slide was then coated with PMMA solution by rotating it at low speed for 5-7 seconds and then at high speed for 40-60 seconds. After drying at 70-80°C, a PMMA / graphene / copper foil structure was formed. Next, the PMMA / graphene / copper foil was immersed in ammonium persulfate solution for 2-7 hours to etch away the copper foil substrate. After etching, the PMMA / graphene film was removed from the etching solution and rinsed in deionized water. After cleaning, it was retrieved from a Si / SiO2 substrate and dried. The PMMA was then removed by sequentially immersing the film in acetone, a mixed organic solvent, and isopropanol. Finally, the graphene film was dried at 85-90°C to obtain the graphene film transferred onto the Si / SiO2 substrate.

[0009] The concentration of the polymethyl methacrylate (PMMA) solution was 46-50 mg / mL, and per 4 cm³. 2 Silicon wafers coated with 250-350 μL;

[0010] The concentration of ammonium sulfate solution is 0.1-0.3 mol / L;

[0011] The low-speed rotation is 1200-1500 rpm / min; the high-speed rotation is 3000-5000 r / min.

[0012] The mixed organic solvent consists of acetone and isopropanol in a volume ratio of 1:1.

[0013] (2). Preparation for electro-spray printing: The substrate with graphene film is adsorbed onto the substrate of the electro-spray printing equipment using vacuum adsorption; the prepared precursor solution is added to the airtight syringe, the distance between the bottom of the syringe and the substrate surface is adjusted to 2-3 mm, and a single and stable nanowire jet is formed by applying a bias voltage of 4000-4500V to the syringe.

[0014] The precursor solution contains poly-9-vinylcarbazole as the solute and styrene as the solvent; the concentration of poly-9-vinylcarbazole is 3-5 wt%.

[0015] (3). Printing of nanowire arrays: Set the lateral movement distance of the printing substrate to 160-200 mm, the solution injection rate to 15-50 nL / min, the lateral movement speed to 50-260 mm / s, and the longitudinal movement speed to 0.6-2 mm / s, and start printing to obtain nanowire arrays.

[0016] The nanowires have a diameter of 300-700 nm, an array spacing of 50-300 μm, and a length of 2.0-2.5 cm.

[0017] (4). Plasma etching: The substrate with the nanowire array printed is placed in a plasma etching machine, and the etching gas is oxygen with a flow rate of 80-100 sccm, a radio frequency power of 30-50W, and an etching time of 20-40s to remove the graphene not protected by the nanowires and obtain polymer / graphene nanoribbons.

[0018] (5) Polymer removal: The polymer / graphene nanoribbons are placed in N,N-dimethylformamide solution and ultrasonically treated for 10-20s to remove the polymer on the graphene nanoribbons, so as to obtain graphene nanoribbons attached to the substrate.

[0019] It also includes a substrate pretreatment step:

[0020] Substrate cleaning: First, the Si / SiO2 substrate is cut and ultrasonically cleaned; the cleaning process includes cleaning in deionized water for 15-20 minutes, then cleaning in acetone solution for 20-30 minutes, and finally treating in isopropanol solution for 15-20 minutes.

[0021] Substrate treatment: Use a nitrogen gun to dry the cleaned substrate surface, and then place the substrate in an ozone cleaner for 20-30 minutes to improve the substrate surface activity.

[0022] The graphene nanoribbons prepared by the method are used as conductive channel layers in three-terminal transistor devices.

[0023] The essential features of this invention are:

[0024] Traditional methods for preparing graphene nanoribbons typically require complex steps, such as nanoparticle deposition during metal nanoparticle etching, high-precision cutting during carbon nanotube cleaving, and layer-by-layer construction during atomic assembly. These processes are cumbersome and time-consuming. This invention simplifies the process by requiring only electrohydrodynamic printing, plasma etching, and ultrasonic exfoliation.

[0025] This method utilizes controllable digital nanowire printing technology to print a poly9-vinylcarbazole nanowire mask on the graphene surface, and then uses reactive ion etching to etch away the graphene not protected by the nanowire mask, thus preparing graphene nanoribbons. During the preparation process, the width and spacing of the graphene nanoribbons can be controlled by changing the diameter of the poly9-vinylcarbazole nanowire mask, the nanowire spacing, and the oxygen plasma etching time, thereby controlling the electrical properties of the graphene nanoribbons.

[0026] The method employed in this invention enables large-area, rapid, and low-cost preparation of graphene nanoribbons, as well as precise control of the width and spacing of graphene nanoribbons, providing a foundation for opening the graphene band gap and constructing graphene nanoribbon-based electronic devices.

[0027] The beneficial effects of this invention are as follows:

[0028] (1) The digitally controllable nanowire printing technology used in this invention can print one-dimensional polymer nanowire masks with uniform width and spacing on the graphene surface by precisely adjusting printing parameters, such as bias voltage, printing distance, printing speed, and pattern parameters. The core advantage of this technology is that it has high controllability and flexibility compared with existing graphene nanoribbon preparation technologies, and the nanowire patterns can be freely customized as needed, providing strong technical support for the preparation of high-precision nanoelectronic devices.

[0029] (2) The plasma etching technology used in this invention precisely controls the width and spacing of graphene nanoribbons while maintaining the integrity of the morphology by adjusting the diameter of the nanowire mask and the etching time. This enables the adjustment of the bandgap width of the nanoribbons, realizing the applicability of graphene nanoribbons in transistor devices. In addition, this technology provides new methods and ideas for the fabrication of one-dimensional structures of other similar nanomaterials, promoting the development of nanotechnology and related fields.

[0030] (3) This invention has significant advantages in manufacturing cost and efficiency compared to photolithography and other nanoribbon fabrication methods. Digitally controllable nanowire printing technology avoids the need for expensive masks and photoresists, enabling patterned mask printing; the automated printing process greatly reduces the complexity of the process operations; and it can achieve patterned mask printing in 2×2cm... 2A single printing operation on a silicon wafer of this size requires only 1–10 μL of solution, reducing material consumption during the production process. This enables high-precision and high-efficiency nanoribbon production. Attached image description:

[0031] Figure 1 A schematic diagram illustrating the process of preparing graphene nanoribbons through plasma etching and cleaning to print nanowire masks on graphene.

[0032] Figure 2 The image shows a single poly9-vinylcarbazole nanowire mask printed on a graphene film using a digitally controlled nanowire printer in Example 1, under a 100x magnified optical microscope.

[0033] Figure 3 The image shows the characterization of the poly9-vinylcarbazole nanowire array printed on a graphene film using a digitally controlled nanowire printer in Example 1, under a 20x magnified optical microscope.

[0034] Figure 4 The image shows a single graphene nanoribbon obtained in Example 1 after plasma etching and ultrasonic cleaning to remove the nanowire mask, under a 100x magnified optical microscope.

[0035] Figure 5 The image shows the graphene nanoribbon array obtained in Example 1 after removing the nanowire mask by plasma etching and ultrasonic cleaning under a 10x magnified optical microscope.

[0036] Figure 6 This is a scanning electron microscope image of a single graphene nanoribbon in Example 1 at 100,000x magnification.

[0037] Figure 7 This is a characterization image of a single graphene nanoribbon in Example 1 under an atomic force microscope.

[0038] Figure 8 The graphene nanoribbon device in Example 1 has a transfer characteristic curve.

[0039] Among them, 1 is a Si / SiO2 substrate, 2 is a graphene film, 3 is a poly9-vinylcarbazole nanowire mask, and 4 is a graphene nanoribbon after plasma etching and ultrasonic removal of the polymer nanowire mask by N,N-dimethylformamide.

[0040] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments: Specific implementation plan:

[0041] like Figure 1As shown, the left side of the image shows a PVK nanowire array mask (3) uniformly printed on a graphene film 2 transferred to a Si / SiO2 substrate 1. The middle part of the image represents oxygen plasma (O2). + The process involves etching the graphene film not covered by the PVK nanowire array mask, causing it to react and release CO2 gas. The right side of the image shows the graphene nanoribbons 4 obtained after etching and DMF ultrasonic cleaning to remove the PVK nanowire mask. The specific implementation scheme is as follows:

[0042] Example 1:

[0043] (1) Cut the silicon substrate with the SiO2 oxide layer into 2×2cm pieces. 2 The substrate was placed in deionized water and ultrasonically cleaned for 15 minutes. Then, the deionized water was poured out, and acetone solution was added for ultrasonic cleaning for 30 minutes. Finally, the acetone was poured out, and isopropanol solution was added for ultrasonic treatment for 15 minutes to complete the cleaning of the Si / SiO2 substrate. The cleaned substrate surface was dried using a nitrogen gun, and then the substrate was placed in an ozone cleaner for ozone treatment for 30 minutes to improve the substrate surface activity.

[0044] (2) Cut a copper foil (50 μm thick) with a 0.35 nm thick graphene film to a size of 1.5 × 1.5 cm. 2 The copper foil was attached to a clean glass slide using isopropanol. A PMMA solution (46 mg / mL, chlorobenzene solvent) was spin-coated onto the graphene surface using the following parameters: low speed 1500 rpm / min for 5 s, high speed 3000 rpm / min for 60 s. The resulting PMMA / graphene / copper foil structure was then dried at 70°C on a heated stage.

[0045] (3) The PMMA / graphene / copper foil was peeled off from the glass slide and immersed in ammonium persulfate solution (0.2 mol / L, 400 mL) to etch the copper foil substrate for 4 hours, allowing the PMMA / graphene film to float on the surface of the etching solution. The PMMA / graphene film was then removed from the etching solution, washed with deionized water, and transferred to a Si / SiO2 substrate for drying. The PMMA was removed sequentially by immersing the film in acetone, acetone:isopropanol = 1:1 (volume ratio), and isopropanol. Finally, the graphene film was dried at 90°C, successfully transferring graphene to the Si / SiO2 substrate.

[0046] (4) Take 40 mg of poly-9-vinylcarbazole and 1 g of styrene, and stir with a magnetic rotor at room temperature and pressure. The stirring speed is 500 rpm and the stirring time is 4 hours until the poly-9-vinylcarbazole is completely dissolved. The dissolved precursor solution is colorless and transparent.

[0047] (5) The substrate with the graphene film was adsorbed onto the substrate of the electrohydrodynamic inkjet printing equipment using vacuum adsorption. The prepared precursor solution was added to an airtight syringe with an outer diameter of 240 μm and an inner diameter of 60 μm. The injection rate of the solution was set to 15 nL / min. The distance between the bottom of the syringe and the substrate surface was adjusted to 2 mm. A single and stable nanowire jet was formed by applying a bias voltage of 4000 V to the syringe. The lateral movement distance of the printed substrate was set to 180 mm, the lateral movement speed was 50 mm / s, and the longitudinal movement speed was 0.6 mm / s. In the obtained nanowire array, the diameter of the nanowires was 400 nm, the spacing between the nanowire arrays was 100 μm, and the length of the nanowires was 2.0 cm. The substrate temperature was adjusted to 35 °C and heated for 5 min. The substrate could be removed without damaging the nanowires on the substrate.

[0048] (6) Place the substrate with the nanowire array printed in a plasma etching machine. The etching gas is oxygen, the gas flow rate is 80 sccm, the radio frequency power is 30W, and the etching time is 20s. This will remove the graphene that is not under the nanowires and obtain polymer / graphene nanoribbons.

[0049] (7) The polymer / graphene nanoribbons were placed in an N,N-dimethylformamide solution and the PVK nanowire array mask on the graphene nanoribbons was removed by ultrasonic treatment for 20 s. After ultrasonic treatment, the residual liquid was dried by blowing with a small amount of N2 gas to obtain the graphene nanoribbons attached to the substrate.

[0050] (8) Measure 0.5g of gold wire as the evaporation source, and deposit source and drain electrodes with a thickness of 50-80nm on graphene nanoribbons by evaporation deposition technology. Use interdigitated electrode mask with an interdigitation spacing of 100μm.

[0051] Figure 2 and Figure 3 The image shows an optical microscope image of the nanowire array prepared on graphene nanoribbons by electrohydrodynamic printing technology in Example 1. It can be seen that the printed nanowire array is uniformly arranged, with a spacing of about 100 μm between the nanowires and a diameter of about 300 nm.

[0052] Figure 4 and Figure 5 This is an optical microscope image of a graphene nanoribbon array after plasma etching and ultrasonic removal of the nanowire mask. Figure 4 The morphology of graphene nanoribbons observed at 100x magnification. Figure 5The image shows the fabricated nanoribbon array at 10x magnification, including graphene nanoribbons and portions where graphene films were not transferred onto the substrate. It is clearly visible that after etching and cleaning processes, the nanowires in the untransferred graphene portions were completely removed, and the remaining graphene nanoribbon array retains excellent surface morphology and uniformity, confirming the feasibility of the process.

[0053] Figure 6 The image shows a single graphene nanoribbon obtained in Example 1 under a scanning electron microscope at 100,000x magnification. The nanoribbon has a uniform width of approximately 250 nm.

[0054] Figure 7 The image shows the atomic force microscopy characterization of the single graphene nanoribbon obtained in Example 1. The upper right curve is the height curve of the nanoribbon at the line connecting points A and B, which shows that the height of the nanoribbon is 2.8 nm.

[0055] Figure 8 The transfer characteristic curves of a graphene nanoribbon transistor device, measured using a Keithley 4200A instrument, show the current versus gate voltage variation, with a test range of -60V to 60V. The transfer characteristic curves of the graphene nanoribbon device exhibit a nonlinear characteristic with hysteresis. This nonlinear characteristic indicates that the transistor's on / off state can be precisely controlled by adjusting the gate voltage, thus achieving more flexible threshold voltage control. Within a certain gate voltage range, the nonlinear characteristic can provide higher gain, achieving effective signal amplification. The hysteresis effect indicates that the transistor's current-voltage characteristics exhibit path dependence and a memory effect.

[0056] Example 2:

[0057] (1) Cut the silicon substrate with the SiO2 oxide layer into 2×2cm pieces. 2 The substrate was placed in deionized water and ultrasonically cleaned for 15 minutes. Then, the deionized water was poured out, and acetone solution was added for ultrasonic cleaning for 30 minutes. Finally, the acetone was poured out, and isopropanol solution was added for ultrasonic treatment for 15 minutes to complete the cleaning of the Si / SiO2 substrate. The cleaned substrate surface was dried using a nitrogen gun, and then the substrate was placed in an ozone cleaner for ozone treatment for 30 minutes to improve the substrate surface activity.

[0058] (2) Prepare an ammonium persulfate solution (0.2 mol / L) for etching the copper foil substrate and a PMMA solution (46 mg / mL) for preparing the support layer. Cut the copper foil (50 μm thick) with a 0.35 nm thick graphene film to a size of 1.5 × 1.5 cm. 2The copper foil was attached to a clean glass slide using an isopropanol solution. PMMA solution (46 mg / mL) was then spin-coated onto the graphene surface using the following parameters: low speed 1500 rpm / min for 5 s, high speed 3000 rpm / min for 60 s. The slides were then transferred to a heated stage and dried at 70°C to obtain the PMMA / graphene / copper foil structure.

[0059] (3) The PMMA / graphene / copper foil was peeled off from the glass slide and immersed in an ammonium persulfate solution (0.2 mol / L, 400 mL) to etch the copper foil substrate. The PMMA / graphene film was then etched using the ammonium persulfate solution, causing it to float on the surface of the etching solution. The PMMA / graphene film was removed from the etching solution, washed with deionized water, and then transferred to a Si / SiO2 substrate for drying. It was then sequentially immersed in acetone, acetone:isopropanol (1:1), and isopropanol to remove PMMA. Finally, the graphene film was dried at 90°C, successfully transferring graphene to the Si / SiO2 substrate.

[0060] (4) Take 40 mg of poly-9-vinylcarbazole and 1 g of styrene, and stir with a magnetic rotor at room temperature and pressure. The stirring speed is 500 rpm and the stirring time is 4 hours until the poly-9-vinylcarbazole is completely dissolved. The dissolved precursor solution is colorless and transparent.

[0061] (5) The substrate with the graphene film was adsorbed onto the substrate of the electrohydrodynamic inkjet printing equipment using vacuum adsorption. The prepared precursor solution was added to an airtight syringe with an outer diameter of 300 μm and an inner diameter of 160 μm. The injection rate of the solution was set to 50 nL / min. The distance between the bottom of the syringe and the substrate surface was adjusted to 2.5 mm. A single and stable nanowire jet was formed by applying a bias voltage of 4500 V to the syringe. The lateral movement distance of the printed substrate was set to 180 mm, the lateral movement speed was 260 mm / s, and the longitudinal movement speed was 0.6 mm / s. In the obtained nanowire array, the diameter of the nanowires was 700 nm, the spacing between the nanowire arrays was 100 μm, and the length of the nanowires was 2.0 cm. The substrate temperature was adjusted to 35 °C and heated for 5 min. The substrate could be removed without damaging the nanowires on the substrate.

[0062] (6) Place the substrate with the nanowire array printed in a plasma etching machine. The etching gas is oxygen, the flow rate is 80 sccm, the radio frequency power is 30W, and the etching time is 40s. This will remove the graphene that is not under the nanowires and obtain polymer / graphene nanoribbons.

[0063] (7) The polymer / graphene nanoribbons were placed in an N,N-dimethylformamide solution and ultrasonically treated for 20 seconds to remove the polymer from the graphene nanoribbons. After ultrasonication, the residual liquid was dried by blowing with a small amount of N2 gas to obtain the graphene nanoribbons.

[0064] (8) Measure 0.5g of gold wire as the evaporation source, and deposit source and drain electrodes with a thickness of 50-80nm on graphene nanoribbons by evaporation deposition technology. Use interdigitated electrode mask with an interdigitation spacing of 100μm.

[0065] As can be seen from the above embodiments, this invention successfully achieves the one-dimensional patterning of graphene nanoribbons by combining electrohydrodynamic printing and plasma etching processes. In this process, EHD printing is used for precise protective layer deposition, a step that ensures high precision and uniformity of the pattern. Subsequently, an etching step removes areas not covered by the protective material, thereby precisely forming the desired specific patterned nanostructure.

[0066] The graphene nanoribbons prepared in this invention exhibit significant one-dimensional properties. The measured transfer characteristic curves show that the on / off ratio of the graphene nanoribbon transistor is approximately 12, higher than that of traditional bandgap-free graphene materials (typically with on / off ratios between 1 and 2), indicating that the nanoribbon structure prepared by this process successfully introduces a bandgap. Furthermore, as... Figure 8 The nonlinear portion (-60V to 60V) of the IV transfer characteristic curves shown indicates that the electrical properties of graphene nanoribbons exhibit semiconductor material characteristics different from those of conductors. Furthermore, Figure 8 The positive and negative scan IV transfer characteristic curves shown do not overlap, exhibiting field-effect modulation capability and semiconductor material characteristics similar to the hysteresis effect of field-effect transistors, opening up new paths for the manufacture of high-performance electronic devices.

[0067] Matters not covered in this invention are common knowledge.

Claims

1. A method for preparing graphene nanoribbons based on nanowire mask printing technology, characterized by the following process steps: (1). Graphene film transfer: A copper foil with a graphene film grown on it is attached to a glass slide with isopropanol. The slide is then coated with PMMA solution by rotating it at a low speed for 5-7 seconds and at a high speed for 40-60 seconds. After drying at 70-80°C, a PMMA / graphene / copper foil structure is formed. Then, the PMMA / graphene / copper foil is immersed in ammonium persulfate solution for 2-7 hours to etch away the copper foil substrate. After etching, the PMMA / graphene film is removed from the etching solution and washed in deionized water. After cleaning, it is removed and dried on a Si / SiO2 substrate. Then, it is placed in acetone, mixed organic solvent and isopropanol in sequence to remove PMMA. Finally, the graphene film is dried at 85-90℃ to obtain the graphene film transferred on the Si / SiO2 substrate. The concentration of the polymethyl methacrylate (PMMA) solution is 46-50 mg / mL. (2). Preparation for electro-injection printing: The substrate with graphene film is adsorbed onto the substrate of the electro-hydraulic inkjet printing equipment using vacuum adsorption; the prepared precursor solution is added to the airtight syringe, the distance between the bottom of the syringe and the substrate surface is adjusted to 2-3 mm, the injection rate of the solution is set to 15-50 nL / min, and a single and stable nanowire jet is formed by applying a bias voltage of 4000-4500V to the syringe. The precursor solution contains poly-9-vinylcarbazole as the solute and styrene as the solvent; the concentration of poly-9-vinylcarbazole is 3-5 wt%. (3). Printing of nanowire arrays: Set the lateral movement distance of the printing substrate to 160-200mm, the lateral movement speed to 50-260mm / s, and the longitudinal movement speed to 0.6-2mm / s, and start printing to obtain nanowire arrays; The nanowires have a diameter of 300-700 nm, an array spacing of 50-300 μm, and a length of 2.0-2.5 cm. (4). Plasma etching: The substrate with the nanowire array printed is placed in a plasma etching machine, and the etching gas is oxygen with a flow rate of 80-100 sccm, a radio frequency power of 30-50W, and an etching time of 20-40s to remove the graphene not protected by the nanowires and obtain polymer / graphene nanoribbons. (5) Polymer removal: The polymer / graphene nanoribbon is placed in an N,N-dimethylformamide solution and ultrasonically treated for 10-20s to remove the polymer on the graphene nanoribbon, thus obtaining the graphene nanoribbon attached to the substrate.

2. The method for preparing graphene nanoribbons based on nanowire mask printing technology as described in claim 1, characterized in that: The substrate pretreatment steps in step (1): Substrate cleaning: First, the Si / SiO2 substrate is cut and ultrasonically cleaned; the cleaning process includes cleaning in deionized water for 15-20 minutes, then cleaning in acetone solution for 20-30 minutes, and finally treating in isopropanol solution for 15-20 minutes. Substrate treatment: Use a nitrogen gun to dry the cleaned substrate surface, and then place the substrate in an ozone cleaner for 20-30 minutes to improve the substrate surface activity.

3. The method for preparing graphene nanoribbons based on nanowire mask printing technology as described in claim 1, characterized in that the concentration of ammonium sulfate solution is 0.1-0.3 mol / L; the composition of the mixed organic solvent is acetone and isopropanol, and the volume ratio of the two is 1:

1.

4. The method for preparing graphene nanoribbons based on nanowire mask printing technology as described in claim 1, characterized in that each 4cm... 2 The silicon wafer is coated with 250-350 μL.

5. The method for preparing graphene nanoribbons based on nanowire mask printing technology as described in claim 1, characterized in that the low-speed rotation is 1200-1500 rpm / min; and the high-speed rotation is 3000-5000 r / min.

6. The application of the graphene nanoribbons prepared by the method described in claim 1, characterized in that: Used as a conductive channel layer in three-terminal transistor devices.

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