Preparation method of two-dimensional material heterojunction

Abstract

The embodiment of the invention provides a preparation method of a two-dimensional material heterojunction. The preparation method comprises the following steps: S1, obtaining a two-dimensional material; and S2, manipulating the heterojunction of the two-dimensional material by using a probe of a scanning tunneling microscope. According to the preparation method of the two-dimensional material provided by the embodiment of the invention, the heterojunction of the two-dimensional material can be accurately controlled, and the structure of the two-dimensional material cannot be irreversibly damaged. The embodiment of the invention further provides the two-dimensional material.

Description

Technical Field

[0001] The present application belongs to the field of semiconductor material technology, and in particular, relates to a method for preparing a two-dimensional material heterojunction. Background Art

[0002] In recent years, with the rapid development of micro-nanoelectronics technology and materials science, two-dimensional materials such as graphene and transition metal chalcogenides have attracted widespread attention due to their excellent electrical and mechanical properties.

[0003] One-dimensional heterojunctions or domain boundaries in two-dimensional materials are special structural defects that have an important influence on the physical properties of the material. Therefore, achieving precise manipulation of heterojunctions has become one of the important research directions in this field. Traditional methods such as chemical etching and ion implantation often cause irreversible damage to the material and cannot achieve reversible manipulation of the heterojunction. Summary of the invention

[0004] In response to the problems existing in the above-mentioned related technologies, the present invention provides a method for preparing a two-dimensional material and a two-dimensional material, which can accurately manipulate the heterojunction of the two-dimensional material without irreversibly destroying the structure of the two-dimensional material.

[0005] In a first aspect, the present application provides a method for preparing a two-dimensional material heterojunction, comprising:

[0006] Step S1: obtaining the two-dimensional material; and

[0007] Step S2: using a probe of a scanning tunneling microscope to manipulate the heterojunction of the two-dimensional material.

[0008] In some implementations, before step S2, the method further includes:

[0009] The morphology and structure of the two-dimensional material are obtained through the scanning tunneling microscope.

[0010] In some embodiments, the two-dimensional material is a single-layer island-shaped two-dimensional material, and the step S2 includes: using the probe of the scanning tunneling microscope to manipulate the heterojunction of the single-layer island-shaped two-dimensional material by means of voltage pulses; and / or using the probe of the scanning tunneling microscope to manipulate the heterojunction of the single-layer island-shaped two-dimensional material by means of electron injection; and / or using the probe of the scanning tunneling microscope to manipulate the heterojunction of the single-layer island-shaped two-dimensional material by means of mechanical impact.

[0011] In some embodiments, the use of the probe of the scanning tunneling microscope to manipulate the heterojunction of the single-layer island-shaped two-dimensional material by means of voltage pulses includes:

[0012] Using the scanning tunneling microscope, determining the position of the single-layer island-shaped two-dimensional material;

[0013] placing the probe above the monolayer island-shaped two-dimensional material; and

[0014] The voltage and tunneling current are fixed, the height of the probe is kept constant, and vertical and / or horizontal voltage pulses are applied to the single-layer island-shaped two-dimensional material to manipulate the heterojunction of the single-layer island-shaped two-dimensional material.

[0015] In some embodiments, the use of the probe of the scanning tunneling microscope to manipulate the heterojunction of the single-layer island-shaped two-dimensional material by electron injection includes:

[0016] Using the scanning tunneling microscope, determining the position of the single-layer island-shaped two-dimensional material;

[0017] placing the probe above the heterojunction of the monolayer island-shaped two-dimensional material; and

[0018] The voltage and tunneling current are fixed, and electrons are injected into the heterojunction of the single-layer island-shaped two-dimensional material through scanning and / or spectroscopy operations to manipulate the heterojunction of the single-layer island-shaped two-dimensional material.

[0019] In some embodiments, the use of the probe of the scanning tunneling microscope to manipulate the heterojunction of the single-layer island-shaped two-dimensional material by mechanical impact includes:

[0020] Using the scanning tunneling microscope, determining the position of the single-layer island-shaped two-dimensional material;

[0021] placing the probe above the monolayer island-shaped two-dimensional material; and

[0022] The voltage and tunneling current are fixed, the height between the probe and the single-layer island-shaped two-dimensional material is adjusted, and the single-layer island-shaped two-dimensional material is mechanically impacted by the probe to manipulate the heterojunction of the single-layer island-shaped two-dimensional material.

[0023] In some embodiments, the two-dimensional material is a double-layer island-shaped two-dimensional material, and step S2 includes:

[0024] The probe of the scanning tunneling microscope is used to manipulate the heterojunction of the double-layer island-shaped two-dimensional material through voltage pulses, electron injection and / or mechanical impact.

[0025] In some embodiments, the two-dimensional material is an island-shaped niobium diselenide two-dimensional material, and obtaining the two-dimensional material comprises:

[0026] obtaining a double-layer graphene-covered silicon carbide substrate; and

[0027] By using molecular beam epitaxy technology, high-purity selenium atoms and niobium atoms are evaporated onto the silicon carbide substrate in a ratio greater than 20:1.

[0028] In some embodiments, after using the molecular beam epitaxy technology to evaporate high-purity selenium atoms and niobium atoms in a ratio greater than 20:1 onto the silicon carbide substrate to obtain the two-dimensional material, the method further includes: performing a high-temperature annealing treatment on the two-dimensional material.

[0029] In a second aspect, an embodiment of the present application provides a two-dimensional material, which is made by any of the methods described above.

[0030] Compared with the existing preparation methods of two-dimensional materials, the preparation method of two-dimensional materials provided in the embodiments of the present application manipulates the heterojunction of the two-dimensional material through the probe of a scanning tunneling microscope, thereby being able to accurately introduce, move and erase the heterojunction of the two-dimensional material without destroying the structure of the two-dimensional material, so as to change the physical and chemical properties of the two-dimensional material. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related technologies, the drawings required for use in the embodiments or the related technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0032] Figure 1 A schematic diagram of a process for preparing a two-dimensional material provided in an embodiment of the present invention;

[0033] Figure 2a to Figure 2c A scanning tunneling microscope image of a two-dimensional material provided by an embodiment of the present invention and a height fluctuation curve along a marked direction;

[0034] Figures 3a to 3e The preparation process involved in the preparation method of the two-dimensional material provided in Example 1 of the present application and the scanning tunneling microscope image of the two-dimensional material, wherein the arrows in the figure indicate the lattice arrangement direction of the two-dimensional material;

[0035] Figures 4a to 4e The preparation process involved in the preparation method of the two-dimensional material provided in Example 2 of the present application and the scanning tunneling microscope image of the two-dimensional material, wherein the arrow in the figure indicates the original operation position of the two-dimensional material;

[0036] Figure 5a to Figure 5cThe preparation process involved in the preparation method of the two-dimensional material provided in Example 3 of the present application and the scanning tunneling microscope image of the two-dimensional material, wherein the arrow in the figure indicates the original operation position of the two-dimensional material;

[0037] Figures 6a to 6c The preparation process involved in the preparation method of the two-dimensional material provided in Example 4 of the present application and the scanning tunneling microscope image of the two-dimensional material, wherein the arrow in the figure indicates the original operation position of the two-dimensional material;

[0038] Figure 7 a to Figure 7 d is a scanning tunneling microscope image of the two-dimensional material involved in the preparation method of the two-dimensional material provided in Example 5 of the present application and its height fluctuation curve along the marked direction, wherein the arrow in the figure indicates the original operating position of the two-dimensional material.

[0039] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0041] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0042] It should also be understood that the terms used in this application specification are only for the purpose of describing specific embodiments and are not intended to limit the application. As used in this application specification and the appended claims, the singular forms of "a", "an" and "the" are intended to include plural forms unless the context clearly indicates otherwise. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0043] Therefore, see Figure 1 The present invention provides a method for preparing a two-dimensional material heterojunction, the method comprising:

[0044] Step S1: obtaining the two-dimensional material; and

[0045] Step S2: using a probe of a scanning tunneling microscope to manipulate the heterojunction of the two-dimensional material.

[0046] Specifically, refer to Figure 2a to Figure 2c , two-dimensional materials refer to materials with a thickness of only a single layer or a few atomic layers, such as graphene, transition metal sulfides (such as MoS2), etc. Due to their unique low-dimensional structure, these materials exhibit many abnormal electronic and mechanical properties. In two-dimensional charge density wave materials, the arrangement of electrons in the lattice will form periodic fluctuations, which are charge density waves. Charge density wave superlattice structures are usually accompanied by the formation of heterojunctions or domain boundaries, which refer to the dividing lines between charge density wave regions of different phases. These heterojunctions have an important influence on the physical properties of the material.

[0047] Scanning tunneling microscopy is a surface characterization technology that can achieve atomic-level resolution. Scanning tunneling microscopy uses the tunneling effect in quantum mechanics to detect and manipulate surface atoms through a tiny tunneling current between an extremely fine metal probe and the sample surface. By adjusting the distance between the probe and the sample, such as the surface of a two-dimensional material, atomic-scale morphological information of the sample surface can be obtained. In addition to the characterization function, the scanning tunneling microscope probe can also be used as an effective manipulation tool to achieve precise manipulation of the surface atoms or molecules of two-dimensional materials by applying voltage pulses, electron injection or mechanical impact.

[0048] Compared with the existing preparation methods of two-dimensional materials, the preparation method of two-dimensional materials provided in the embodiments of the present application manipulates the heterojunction of the two-dimensional material through the probe of a scanning tunneling microscope, thereby being able to accurately introduce, move and erase the heterojunction of the two-dimensional material without destroying the structure of the two-dimensional material, so as to change the physical and chemical properties of the two-dimensional material.

[0049] Furthermore, in some embodiments of the present application, before step S2, the method further includes:

[0050] The morphology and structure of the two-dimensional material are obtained through the scanning tunneling microscope.

[0051] Specifically, scanning tunneling microscopy is a technology that can image and characterize surfaces at the atomic scale. Using the quantum tunneling effect, the electronic state of the sample surface is detected by the tunneling current between a special probe and the sample surface. The probe scans the sample surface and records the information of the tunneling current changing with position, thereby obtaining a distribution map of the surface morphology and electronic state. Before step S2, that is, before manipulating the heterojunction of the two-dimensional material using the probe of the scanning tunneling microscope, it is necessary to obtain the morphology and structure of the two-dimensional material through a scanning tunneling microscope, so as to facilitate the acquisition of the morphological structure of the one-dimensional heterojunction, that is, to achieve the manipulation of the one-dimensional heterojunction.

[0052] Furthermore, in some embodiments of the present application, the two-dimensional material is a single-layer island-shaped two-dimensional material, and the step S2 includes: using the probe of the scanning tunneling microscope to manipulate the heterojunction of the single-layer island-shaped two-dimensional material by means of voltage pulses; and / or using the probe of the scanning tunneling microscope to manipulate the heterojunction of the single-layer island-shaped two-dimensional material by means of electron injection; and / or using the probe of the scanning tunneling microscope to manipulate the heterojunction of the single-layer island-shaped two-dimensional material by means of mechanical impact.

[0053] Specifically, the high spatial resolution of the scanning tunneling microscope enables the operator to clearly see the structure and position of the heterojunction of the two-dimensional material. Once the heterojunction is located, the operator can use the scanning tunneling microscope probe to apply a local electric field in the heterojunction area to induce the heterojunction to move, which in turn causes the local morphology structure and local electronic state of the material to change. Therefore, the impact of the scanning tunneling microscope manipulation can be directly observed during the imaging process. In addition, through voltage pulse technology, a local electric field can be generated in the charge density wave material, changing the distribution and arrangement of electrons, thereby causing changes in the charge density wave structure, artificially creating or manipulating the position and shape of the heterojunction, and inducing a phase structure with special properties.

[0054] Mechanical impact control is a technology that uses external mechanical shock or pressure to control materials. Two-dimensional charge density wave materials have periodic charge distribution. Mechanical impact control can change the charge distribution by changing the external pressure or stress of the material, thereby adjusting its phase structure or charge density wave superlattice. Chirality is one of the important characteristics of the charge density wave superlattice structure. Charge density wave superlattices of different chirality have different electronic structures and physical properties. By mechanically impacting and controlling two-dimensional charge density wave materials, charge density wave superlattices of different chirality can be induced, thereby achieving the induction and manipulation of the one-dimensional heterojunction structure in the two-dimensional charge density wave material.

[0055] The two-dimensional material involved in the embodiment of the present application is a single-layer island-shaped two-dimensional material. The step S2 includes: using the probe of the scanning tunneling microscope to manipulate the heterojunction of the single-layer island-shaped two-dimensional material by means of voltage pulses, electron injection and / or mechanical impact. Therefore, the heterojunction of the two-dimensional material can be accurately introduced, moved and erased without destroying the structure of the two-dimensional material to change the physical and chemical properties of the two-dimensional material.

[0056] The following examples take a single-layer island-shaped niobium diselenide as an example to describe in detail the preparation method of the two-dimensional material provided in the examples of the present application.

[0057] Embodiment 1

[0058] Reference Figures 3a to 3e In this embodiment, the use of the probe of the scanning tunneling microscope to manipulate the heterojunction of the single-layer island-shaped two-dimensional material by means of voltage pulses includes:

[0059] Using the scanning tunneling microscope, determining the position of the single-layer island-shaped two-dimensional material;

[0060] placing the probe above the monolayer island-shaped two-dimensional material; and

[0061] The voltage and tunneling current are fixed, the height of the probe is kept constant, and vertical and / or horizontal voltage pulses are applied to the single-layer island-shaped two-dimensional material to manipulate the heterojunction of the single-layer island-shaped two-dimensional material.

[0062] Specifically, first, Figure 3a As shown, scan the graph in constant current mode to determine if Figure 3c The initial position of the monolayer island of niobium diselenide is shown, and then the probe is placed above the monolayer niobium diselenide island to be manipulated, the voltage and tunneling current are fixed, the height of the probe is kept constant, a vertical voltage pulse is applied, and the positive / magnitude / duration of the applied voltage is adjusted. It is possible to change the chirality of the charge density wave in some areas of the monolayer niobium diselenide island without introducing additional defects into the island-shaped two-dimensional material, thereby realizing the construction / manipulation of the one-dimensional heterojunction structure in the niobium diselenide plane at the nanoscale, thereby obtaining Figure 3d The one-dimensional heterojunction structure shown can be imaged visually by scanning tunneling microscopy. The vertical voltage pulse applies voltage along the vertical direction of the heterojunction, which can precisely control the position and movement of the heterojunction, so it is suitable for introducing heterojunctions in a very small spatial localized area.

[0063] In addition, Figure 3b As shown, the one-dimensional heterojunction structure can also be manipulated by applying a horizontal voltage pulse through the probe. The specific method is: first scan the image in constant current mode to determine the initial position of the monolayer island niobium diselenide; then place the probe above the graphene substrate, close to the edge of the monolayer niobium diselenide island that needs to be manipulated, fix the voltage and tunneling current, keep the height of the probe constant, and apply a horizontal voltage pulse in the parallel direction of the heterojunction. This can achieve the change of the charge density wave chirality of part of the monolayer niobium diselenide island in a larger area without introducing additional defects to the island-shaped two-dimensional material, thereby realizing the construction / manipulation of the one-dimensional heterojunction structure in the niobium diselenide plane at the nanoscale. This method is suitable for applications that require the regulation of heterojunctions over a large area, and can quickly manipulate heterojunctions throughout the material. It can be used for domain engineering and domain patterning of large-area ferroelectric thin films.

[0064] Embodiment 2

[0065] Reference Figures 4a to 4e In this embodiment, the use of the probe of the scanning tunneling microscope to manipulate the heterojunction of the single-layer island-shaped two-dimensional material by electron injection includes:

[0066] Using the scanning tunneling microscope, determining the position of the single-layer island-shaped two-dimensional material;

[0067] placing the probe above the heterojunction of the monolayer island-shaped two-dimensional material; and

[0068] The voltage and tunneling current are fixed, and electrons are injected into the heterojunction of the single-layer island-shaped two-dimensional material through scanning and / or spectroscopy operations to manipulate the heterojunction of the single-layer island-shaped two-dimensional material.

[0069] Specifically, first scan the image in constant current mode to determine if Figure 4c The initial position of the island-like monolayer NbSe is shown in Fig. Figure 4a As shown in the figure, the probe is placed above the one-dimensional heterojunction in the monolayer niobium diselenide island that needs to be manipulated, the voltage and tunneling current are fixed, and scanning or spectrum operation is performed to achieve electron injection. Therefore, by adjusting the voltage and tunneling current, scanning speed and other parameters, the one-dimensional heterojunction structure in the monolayer niobium diselenide island material surface can be controlled without introducing additional defects into the island-shaped two-dimensional material. Figure 4b As shown in the figure, the transition rate is plotted as a function of the tunneling current on a logarithmic scale, and its linear relationship can indicate that the manipulation process of this one-dimensional heterojunction structure is a single electron tunneling process. Figure 4d As shown, the movement of the one-dimensional heterojunction structure can be directly imaged by scanning tunneling microscopy, as shown in Figure 4e As shown, after the heterojunction moves, the electron injection operation is performed by scanning the image again, and the position of the one-dimensional heterojunction structure can be manipulated to return to the initial position.

[0070] Embodiment 3

[0071] Reference Figure 5a to Figure 5c In this embodiment, the use of the probe of the scanning tunneling microscope to manipulate the heterojunction of the single-layer island-shaped two-dimensional material by mechanical impact includes:

[0072] Using the scanning tunneling microscope, determining the position of the single-layer island-shaped two-dimensional material;

[0073] placing the probe above the monolayer island-shaped two-dimensional material; and

[0074] The voltage and tunneling current are fixed, the height between the probe and the single-layer island-shaped two-dimensional material is adjusted, and the single-layer island-shaped two-dimensional material is mechanically impacted by the probe to manipulate the heterojunction of the single-layer island-shaped two-dimensional material.

[0075] Specifically, first, scan the graph in constant current mode to determine if Figure 5b The arrows show the initial positions of the island-like monolayer NbSe. Figure 5a As shown in the figure, the probe is placed above the monolayer niobium diselenide island to be manipulated, the voltage and tunneling current are fixed, the distance between the probe and the sample surface is manually adjusted, and the probe is used to apply mechanical impact to the surface of the island-shaped two-dimensional material. Using this method, the construction / manipulation of the one-dimensional heterojunction structure in the niobium diselenide plane can be achieved at the nanoscale, such as Figure 5c The one-dimensional heterojunction structure shown can be imaged visually by scanning tunneling microscopy.

[0076] Embodiment 4

[0077] Furthermore, in some embodiments of the present application, the two-dimensional material is a double-layer island-shaped two-dimensional material, and the step S2 includes:

[0078] The probe of the scanning tunneling microscope is used to manipulate the heterojunction of the double-layer island-shaped two-dimensional material through voltage pulses, electron injection and / or mechanical impact.

[0079] Specifically, first scan the image in constant current mode to determine if Figure 6b The arrows show the initial positions of the bilayer islands of NbSe. Figure 6a As shown in the figure, the probe is placed above the double-layer niobium diselenide island to be manipulated, the voltage and tunneling current are fixed, the height of the probe is kept constant, and a vertical voltage pulse is applied. By adjusting the positive / negative / magnitude / duration of the applied voltage, the chirality of the charge density wave in part of the top layer of the double-layer niobium diselenide island can be changed without introducing additional defects into the island-shaped two-dimensional material, thereby realizing the construction / manipulation of the one-dimensional heterojunction structure in the niobium diselenide plane at the nanoscale, such as Figure 6c As shown, the one-dimensional heterojunction structure can be imaged visually by scanning tunneling microscopy.

[0080] Of course, for double-layer island-shaped two-dimensional materials, the induction and manipulation of one-dimensional structures can also be achieved through the injection of electrons or mechanical impact operations.

[0081] Embodiment 5

[0082] Reference Figure 7 a to Figure 7c. In this embodiment, based on the probe manipulation technology of the scanning tunneling microscope, the phase structure of the island-shaped niobium diselenide two-dimensional material can be changed at the nanoscale by the method of mechanical impact of the probe, and the single-layer octahedral configuration (T-type) surface phase structure of some areas is changed to a triangular prism configuration (H-type) phase structure. The specific method is: first scan the image in the constant current mode to determine the following: Figure 7 The arrow in a indicates the initial position of the T-shaped monolayer island of niobium diselenide. Then, the probe is placed above the monolayer niobium diselenide island to be manipulated, the voltage and tunneling current are fixed, the distance between the probe and the sample surface is manually adjusted, and the probe is used to apply mechanical impact to the surface of the island-shaped two-dimensional material. Figure 7 As shown in b, the local surface T-type phase structure of the monolayer island niobium diselenide is changed to the H-type phase structure at the nanoscale. Figure 7 c and Figure 7 d is the atomic-resolution scanning tunneling microscopy image of a single-layer niobium diselenide with a triangular prism configuration (H-type) phase structure and the height fluctuation curve along the marked direction. Its superstructure period is measured to be 1.06nm.

[0083] Further, refer again to Figure 2a to Figure 2c In some embodiments of the present application, the two-dimensional material is an island-shaped niobium diselenide two-dimensional material, and the step of obtaining the two-dimensional material comprises:

[0084] obtaining a double-layer graphene-covered silicon carbide substrate; and

[0085] By using molecular beam epitaxy technology, high-purity selenium atoms and niobium atoms are evaporated onto the silicon carbide substrate in a ratio greater than 20:1 to obtain the two-dimensional material.

[0086] Specifically, in a vacuum environment, using molecular beam epitaxy technology, etc., high-purity selenium atoms and niobium atoms are evaporated at a ratio greater than 20:1 onto a double-layer graphene-covered silicon carbide substrate to achieve epitaxial growth of a single-layer island of niobium diselenide material. In the process of epitaxial growth of two-dimensional nanomaterials, by adjusting the substrate temperature, it is possible to prepare Figure 2a The single-layer octahedral configuration (T-type) is flat and regular.

[0087] like Figure 2a As shown, the 2D islands of NbSe can be precisely characterized by scanning tunneling microscopy. Figure 2b and Figure 2c Atomic-resolution scanning tunneling microscopy image of a single layer of niobium diselenide with an octahedral configuration (T-type) and the height fluctuation curve along the marked direction. Its superstructure period is measured to be 1.25nm.

[0088] Of course, the niobium diselenide island-shaped two-dimensional material is only an example of a single-layer island-shaped two-dimensional material, and other elements or single elements can also be used to grow two-dimensional materials.

[0089] Furthermore, in some embodiments of the present application, after using the molecular beam epitaxy technology to evaporate high-purity selenium atoms and niobium atoms in a ratio greater than 20:1 onto the silicon carbide substrate to obtain the two-dimensional material, it also includes: performing high-temperature annealing on the two-dimensional material.

[0090] That is, high-temperature annealing of the prepared single-layer island-shaped niobium diselenide two-dimensional island material in a selenium-rich environment can effectively reduce the defect structure inside and at the edge of the niobium diselenide material, and can greatly improve the quality of the island-shaped niobium diselenide two-dimensional material.

[0091] The present application also provides a two-dimensional material, which is prepared by any of the methods described above. The specific preparation method of the two-dimensional material refers to the above embodiment. Since the specific preparation method of the two-dimensional material adopts all the technical solutions of all the above embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here.

[0092] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present application, and these modifications or replacements should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A method for preparing a two-dimensional material heterojunction, characterized in that: include: Step S1: obtaining the two-dimensional material; and Step S2: using a probe of a scanning tunneling microscope to manipulate the heterojunction of the two-dimensional material.

2. The method according to claim 1, characterized in that Before the step S2, the method further includes: obtaining the morphology and structure of the two-dimensional material through the scanning tunneling microscope.

3. The method according to claim 1, characterized in that The two-dimensional material is a single-layer island-shaped two-dimensional material, and the step S2 includes: using the probe of the scanning tunneling microscope to manipulate the heterojunction of the single-layer island-shaped two-dimensional material by means of voltage pulses; and / or using the probe of the scanning tunneling microscope to manipulate the heterojunction of the single-layer island-shaped two-dimensional material by means of electron injection; and / or using the probe of the scanning tunneling microscope to manipulate the heterojunction of the single-layer island-shaped two-dimensional material by means of mechanical impact.

4. The method according to claim 3, characterized in that The method of manipulating the heterojunction of the single-layer island-shaped two-dimensional material by means of voltage pulses using the probe of the scanning tunneling microscope comprises: Using the scanning tunneling microscope, determining the position of the single-layer island-shaped two-dimensional material; placing the probe above the monolayer island-shaped two-dimensional material; and The voltage and tunneling current are fixed, the height of the probe is kept constant, and vertical and / or horizontal voltage pulses are applied to the single-layer island-shaped two-dimensional material to manipulate the heterojunction of the single-layer island-shaped two-dimensional material.

5. The method according to claim 3, characterized in that The method of manipulating the heterojunction of the single-layer island-shaped two-dimensional material by electron injection using the probe of the scanning tunneling microscope comprises: Using the scanning tunneling microscope, determining the position of the single-layer island-shaped two-dimensional material; placing the probe above the heterojunction of the monolayer island-shaped two-dimensional material; and The voltage and tunneling current are fixed, and electrons are injected into the heterojunction of the single-layer island-shaped two-dimensional material through scanning and / or spectroscopy operations to manipulate the heterojunction of the single-layer island-shaped two-dimensional material.

6. The method according to claim 3, characterized in that The method of manipulating the heterojunction of the single-layer island-shaped two-dimensional material by mechanical impact using the probe of the scanning tunneling microscope comprises: Using the scanning tunneling microscope, determining the position of the single-layer island-shaped two-dimensional material; placing the probe above the monolayer island-shaped two-dimensional material; and The voltage and tunneling current are fixed, the height between the probe and the single-layer island-shaped two-dimensional material is adjusted, and the single-layer island-shaped two-dimensional material is mechanically impacted by the probe to manipulate the heterojunction of the single-layer island-shaped two-dimensional material.

7. The method according to claim 1, characterized in that The two-dimensional material is a double-layer island-shaped two-dimensional material, and the step S2 comprises: The probe of the scanning tunneling microscope is used to manipulate the heterojunction of the double-layer island-shaped two-dimensional material through voltage pulses, electron injection and / or mechanical impact.

8. The method according to any one of claims 1 to 7, characterized in that The two-dimensional material is an island-shaped niobium diselenide two-dimensional material, and the step of obtaining the two-dimensional material comprises: obtaining a double-layer graphene-covered silicon carbide substrate; and By using molecular beam epitaxy technology, high-purity selenium atoms and niobium atoms are evaporated onto the silicon carbide substrate in a ratio greater than 20:1 to obtain the two-dimensional material.

9. The method according to claim 8, characterized in that After using the molecular beam epitaxy technology to evaporate high-purity selenium atoms and niobium atoms at a ratio greater than 20:1 onto the silicon carbide substrate to obtain the two-dimensional material, the method further includes: The two-dimensional material is subjected to high temperature annealing treatment.

10. A two-dimensional material, characterized in that: The two-dimensional material is produced by the method according to any one of claims 1 to 9.

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