A method for observing the step-by-step exfoliation of the two-dimensional morphology of crystal materials

Abstract

The present invention discloses a method for observing the step-by-step peeling of the two-dimensional morphology of crystal materials. By analyzing the space group information and structural symmetry of the target crystal, the method realizes the automatic division of different crystal face stacking modes, quickly finds the characteristic crystal face where the bulk material may be peeled out of the two-dimensional morphology, and accurately locates the critical site where the crystal face separation occurs. At the same time, the method provides the details of the interface coupling reconstruction at the critical point of the crystal face separation, and depicts the dynamic evolution image of the atomic bonding / breaking and configuration wave function during the entire peeling process. The present invention obtains the target peeling crystal face of the material by analyzing the symmetry of the crystal structure, the close packing of the crystal face atoms, and the wave function bonding effect, and provides high-precision crystal peeling data, which solves the key problem of the lack of intelligent peeling methods for crystal materials and greatly accelerates the research and development efficiency of two-dimensional materials.

Description

Technical Field

[0001] The present invention relates to the field of semiconductors, and in particular to a method for observing the two-dimensional morphology of a crystal material by stepping and peeling. Background Art

[0002] A century ago, semiconductors such as zinc blende (zb) and wurtzite (wz) were discovered and received great attention. Benefiting from their excellent electronic structure properties, these compounds (such as CdSe, ZnS, etc.) play an important role in the semiconductor industry and have led to the development of modern high-speed electronic information industry. These traditional semiconductors can be prepared by many methods, which can be generally summarized into two paradigms, namely bottom-up and top-down strategies. The former is to build a larger structural system in an additive way with smaller structural units (such as single atoms or molecules), while the latter is to cut larger materials into the target structure in a subtractive way. The above is the classic way to achieve rich device structures and integrated circuits in current semiconductor manufacturing.

[0003] As people's demands for miniaturization, intelligence, novelty and superiority of materials continue to rise, the size of these traditional bulk materials has gradually been reduced, such as one-dimensional nanowires and two-dimensional nanosheets. In recent years, two-dimensional materials have shown a particularly significant impact in promoting scientific and technological progress and industrial transformation. From the perspective of crystal structure, two-dimensional materials can be divided into two categories, namely layered van der Waals materials and non-van der Waals (non-layered) materials. At present, most single-layer two-dimensional materials are obtained from their layered parent bodies, such as MoS2 and black phosphorus. For the three-dimensional crystals known in experiments, only a small part exhibits a layered structure, while most are non-layered. Although a large number of non-layered materials exhibit rich physical properties, achieving their single-layer structure remains a huge challenge. Because it is generally believed that breaking the strong chemical bonds in non-layered crystals is a necessary condition for separating the single layer, while layered materials only need to overcome the weaker van der Waals interactions to achieve exfoliation. It is worth noting that whether it is layered or non-layered crystals, the bonding form of atoms in different crystal planes is different. Therefore, it is worthwhile to investigate whether there is a relatively "soft" crystal plane structure in crystalline materials that allows the single layer structure perpendicular to the crystal plane to be easily separated. However, the current method of exfoliation of two-dimensional materials still mainly remains in the traditional mechanical exfoliation mode. There is a lack of a complete set of rational exfoliation strategies based on structural symmetry and crystal plane bonding characteristics, especially a method to achieve dynamic observation of the entire exfoliation process. Therefore, it is particularly important to develop an intelligent method for observing the two-dimensional morphology of crystalline materials during step-by-step exfoliation. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0005] According to a first aspect of the present invention, a method for observing the two-dimensional morphology of a crystalline material by stepping and peeling is provided, the method comprising:

[0006] Obtain target crystal structure data file;

[0007] Analyzing the atomic stacking mode and bonding type of characteristic crystal planes according to the target crystal structure data file, and screening characteristic crystal planes with weak bonding interactions;

[0008] The step-by-step stretching is performed along the direction perpendicular to the crystal plane, and the step-by-step peeling process is described by the following formula (1):

[0009]

[0010] Where ΔE is the change in total energy of the system during stretching, E (i,0) Corresponding to the instantaneous initial state energy, E (i,1) is the instantaneous steady-state total energy after the crystal plane atoms are stretched by Δd displacement and the structure is relaxed, and A is the size area of the characteristic crystal plane;

[0011] The critical point of crystal plane separation is determined according to the output of formula (1). The energy change at the critical point of crystal plane separation satisfies the law E (i,1) ≤E (i,0) ;

[0012] The instantaneous energy of the entire step-by-step stripping process is summed or integrated until the critical point of interface separation to output the accurate stripping energy data E of the two-dimensional structure. C ;

[0013] The degree of interface reconstruction is judged based on the numerical difference of ΔE between the critical point and the final convergence state.

[0014] Furthermore, a target crystal structure data file is obtained through symmetry analysis and / or phase analysis.

[0015] Furthermore, the target crystal structure data file is used to analyze the atomic stacking mode and bonding type of characteristic crystal planes, and to screen characteristic crystal planes with weak bonding interactions, specifically including:

[0016] Classification is based on the symmetry of the crystal structure, where each crystal plane is paired with atoms according to the arrangement, and the strength of the crystal plane bonding is determined by electronegativity, atomic radius, and bonding / antibonding interactions;

[0017] According to the preset interaction strength threshold, characteristic crystal planes with weak bonding interactions are screened.

[0018] Furthermore, during the step-by-step stretching process perpendicular to the crystal plane, the atomic displacement Δd is determined according to the level of detail of the description of the exfoliation process.

[0019] Furthermore, the summing or integrating of the instantaneous energy of the entire step-stripping process until the critical point of interface separation specifically includes:

[0020] The critical point of interface separation is determined based on whether the surface atoms have broken bonds. Multiple transient intermediate states are inserted in the process of determining the critical point of interface separation to avoid skipping the critical point due to sparse data.

[0021] Furthermore, after performing step stretching in a direction perpendicular to the crystal plane and describing the step peeling process by formula (1), the method further includes:

[0022] The formula (1) is used to predict whether the crystal can achieve two-dimensional morphology exfoliation.

[0023] Furthermore, the method of predicting whether the crystal can achieve two-dimensional exfoliation by using the formula (1) specifically includes:

[0024] By analyzing the change in bonding strength from the interior to the surface of a thick layer of crystal, if the surface bonding is lower than the internal bonding within a preset threshold range, it is determined that the crystal can achieve two-dimensional morphology peeling.

[0025] According to a second aspect of the present invention, there is provided an apparatus for observing the two-dimensional morphology of a crystal material by stepwise peeling, characterized in that the apparatus comprises a processor configured to:

[0026] Obtain target crystal structure data file;

[0027] Analyzing the atomic stacking mode and bonding type of characteristic crystal planes according to the target crystal structure data file, and screening characteristic crystal planes with weak bonding interactions;

[0028] The step-by-step stretching is performed along the direction perpendicular to the crystal plane, and the step-by-step peeling process is described by the following formula (1):

[0029]

[0030] Where ΔE is the change in total energy of the system during stretching, E (i,0) Corresponding to the instantaneous initial state energy, E (i,1) is the instantaneous steady-state total energy after the crystal plane atoms are stretched by Δd displacement and the structure is relaxed, and A is the size area of the characteristic crystal plane;

[0031] The critical point of crystal plane separation is determined according to the output of formula (1). The energy change at the critical point of crystal plane separation satisfies the law E (i,1) ≤E (i,0) ;

[0032] The instantaneous energy of the entire step-by-step stripping process is summed or integrated until the critical point of interface separation to output the accurate stripping energy data E of the two-dimensional structure. C ;

[0033] The degree of interface reconstruction is judged based on the numerical difference of ΔE between the critical point and the final convergence state.

[0034] According to a third aspect of the present invention, a system for observing the two-dimensional morphology of a crystalline material by step-peeling is provided, the system comprising:

[0035] memory for storing computer programs;

[0036] A processor is configured to execute the computer program to implement the method described above.

[0037] According to a fourth aspect of the present invention, a readable storage medium is provided, wherein the readable storage medium stores one or more programs, and the one or more programs can be executed by one or more processors to implement the method described above.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] (1) The present invention can quickly determine whether any crystalline material can be peeled off into a two-dimensional form, and observe the dynamic process of its crystal face step peeling in real time.

[0040] (2) The present invention can locate the critical site of crystal plane separation and provide accurate peeling energy data of the two-dimensional structure of the crystal plane.

[0041] (3) The present invention can provide the degree of reconstruction coupling between the surface and substrate interfaces by analyzing the energy change of the system from the interface separation critical point to the convergence state.

[0042] (4) The present invention is easy to operate and greatly simplifies the research model of traditional crystal material exfoliation. Based on the idea of crystal face exfoliation strategy design and structure-activity relationship verification, it greatly improves the research and development efficiency of two-dimensional materials and makes the entire process more automated.

[0043] (5) The present invention is an independent method that does not rely on a specific program. A series of commercial or open-source software tools on the market can introduce this method to realize the calculation of the step-stripping process. The method can also be programmed into automated equipment such as robotic arms to achieve automated intelligent stripping of materials through in-situ crystal orientation matching and mechanical signal transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In the drawings, which are not necessarily drawn to scale, the same reference numerals may describe similar components in different views. The same reference numerals with letter suffixes or different letter suffixes may represent different instances of similar components. The accompanying drawings generally illustrate various embodiments by way of example and not limitation, and together with the description and claims, serve to illustrate the disclosed embodiments. Where appropriate, the same reference numerals are used throughout the drawings to refer to the same or similar parts. Such embodiments are illustrative and are not intended to be exhaustive or exclusive of the embodiments of the present apparatus or method.

[0045] Figure 1 A schematic diagram of the exfoliation process of layered and non-layered crystals according to an embodiment of the present invention is shown;

[0046] Figure 2 A flow chart of a method for observing the two-dimensional morphology of a crystal material by step-peeling according to an embodiment of the present invention is shown;

[0047] Figure 3 Another flow chart of a method for observing the two-dimensional morphology of a crystal material by step-peeling according to an embodiment of the present invention is shown;

[0048] Figure 4 The figure shows the dynamic evolution of the bonding strength of the orbital wave function during the step-peeling process of the (110) / (100) / (001) crystal plane of the wurtzite crystal according to an embodiment of the present invention;

[0049] Figure 5 The energy change curve of the system during the exfoliation process of the wurtzite crystal (110) according to an embodiment of the present invention is shown;

[0050] Figure 6 A comparison diagram of the strength of the crystal plane bonding action and the peeling energy curve according to an embodiment of the present invention is shown;

[0051] Figure 7 A structural diagram of a device for observing the two-dimensional morphology of a crystal material by step-peeling according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0052] The following examples are merely intended to better illustrate the present invention, but the present invention is not limited to the examples set forth herein. Therefore, non-essential improvements and adjustments to the embodiments made by those skilled in the art based on the above-described invention and applied to other embodiments are still within the scope of the present invention.

[0053] The embodiment of the present invention provides a method for observing the two-dimensional morphology of a crystal material by stepping and peeling. The research object of the method is a crystal material, such as Figure 1As shown, the crystalline materials include two major categories: layered (van der Waals) and non-layered compounds. The characteristic crystal plane is determined by structural symmetry analysis, and then the crystal plane atomic stacking mode and bonding type are analyzed, and the crystal plane is divided according to the bonding / antibonding interaction strength. The target crystal plane with relatively weak surface bonding is step-stretched, and a small atomic displacement is applied each time along the direction perpendicular to the crystal plane, and then a rapid structural relaxation is performed, and the step-stretching is repeated until the crystal plane is separated, and finally a stable two-dimensional structure of the crystal plane is obtained. According to each instantaneous steady-state structure during the stripping process, the change in its bonding strength and the dynamic evolution image of the crystal plane orbital wave function coupling are output. Integrate from the initial state to the critical point to obtain the stripping energy data of the system. Integrate from the critical point to the final stable state to obtain the degree of interface coupling reconstruction.

[0054] The method will be explained in detail below with reference to the specific steps S100-S600. Figure 2 As shown, the method for observing the two-dimensional morphology of a crystal material by stepwise exfoliation begins at step S100, where a target crystal structure data file is obtained. It should be noted that the target crystal structure data file should include crystal materials, where the crystal materials are not limited to a particular crystal system. All crystals in the 32 point groups and 230 space groups in the existing crystal database are applicable.

[0055] In some embodiments, the target crystal structure data file can be obtained through symmetry analysis and / or phase analysis, or directly obtained from a crystal database.

[0056] In step S200, based on the target crystal structure data file, the atomic stacking mode and bonding type of the characteristic crystal planes are analyzed to screen the characteristic crystal planes with weak bonding interactions.

[0057] In some embodiments, the selection of characteristic crystal planes is divided according to the symmetry of the crystal structure, such as (100) / (110) / (111), etc., wherein each crystal plane is atomically paired according to the arrangement, and the strength of the crystal plane bonding interaction is judged by factors such as electronegativity, atomic radius, bonding / antibonding interaction, etc. As an example only, a specific method for screening characteristic crystal planes with weak bonding interactions can be to judge the strength of the crystal plane bonding interaction by factors such as electronegativity, atomic radius, bonding / antibonding interaction, preset an interaction strength threshold, and select characteristic crystal planes below the interaction strength threshold as characteristic crystal planes with weak bonding interactions. It should be noted that the interaction strength threshold may correspond to different interaction strength thresholds according to actual conditions, and the specific value of the interaction strength threshold is not limited in this embodiment.

[0058] In step S300, step stretching is performed along a direction perpendicular to the crystal plane, and the step peeling process is described by the following formula (1):

[0059]

[0060] Where ΔE is the change in total energy of the system during stretching, E (i,0) Corresponding to the instantaneous initial state energy, E (i,1) It is the instantaneous steady-state total energy after the crystal plane atoms are stretched by Δd displacement and the structure is relaxed, and A is the size area of the characteristic crystal plane.

[0061] In step S400, the critical point of crystal plane separation is determined according to the result output by formula (1), and the energy change at the critical point of crystal plane separation satisfies the law E (i,1) ≤E (i,0) .

[0062] At the critical point of crystal plane separation, the system energy curve rapidly decreases due to interface reconstruction. The energy curve of the system during the peeling process consists of a series of saddle-point energies of transient steady-state structures. The more transient intermediate states inserted between the initial and final states, the smoother the curve and the more accurate the detailed data reflected.

[0063] In some embodiments, during the step-by-step stretching process perpendicular to the crystal plane, each atomic displacement Δd is determined based on the level of detail required to describe the exfoliation process. The value of the atomic displacement Δd can be customized; generally, a smaller Δd indicates a more detailed description of the exfoliation process.

[0064] Step S500: sum or integrate the instantaneous energy of the entire step-by-step stripping process until the critical point of interface separation to output accurate stripping energy data E of the two-dimensional structure. C .

[0065] In some embodiments, the critical point of interface separation is determined by observing whether bond breaking occurs in surface atoms, and accurate positioning of the critical point requires inserting as many transient intermediate states as possible to avoid skipping the critical point due to sparse data, resulting in erroneous results.

[0066] Step S600 , judging the degree of interface reconstruction based on the numerical difference between ΔE at the critical point and the final converged state.

[0067] In some embodiments, as Figure 3 As shown, the method for observing the two-dimensional morphology of the crystal material by step-peeling further includes:

[0068] Step S700: Predict whether the crystal can be peeled off in a two-dimensional manner using the formula (1).

[0069] Specifically, to determine whether a material can be peeled off in a two-dimensional form, the change in bonding strength from the inside to the surface of a thick block can be analyzed, requiring that the bonding effect of the surface layer is significantly lower than that of the interior. Therefore, embodiments of the present invention can analyze the change in bonding strength from the inside to the surface of a thick block of a crystal. If the bonding effect of the surface layer is lower than the bonding effect of the interior within a preset threshold range, it is determined that the crystal can be peeled off in a two-dimensional form. The preset threshold is predetermined based on different crystal materials and is not specifically limited in this embodiment.

[0070] The following examples of the present invention will further illustrate the feasibility and progress of the present invention in combination with specific experimental methods.

[0071] Analysis of the symmetry of the wurtzite crystal structure shows that it belongs to space group 186 and P63mc symmetry. Compounds with wurtzite structure include ZnSe, CdSe, GaN, etc. Its three typical characteristic crystal planes are (110), (100) and (001), and the crystal morphology is hexagonal, see Figure 1 .

[0072] For wurtzite materials, bulk structures with the above three characteristic crystal planes were constructed, with a thickness of about 10-50 nm, and the step-by-step peeling method for observing the two-dimensional morphology of the crystal material was used as described above, see Figure 3 . Evaluate the type and strength of bonding interactions of surface atoms Where R and L are atomic sites and orbitals, respectively, and H is the Hamiltonian matrix n is the density matrix element obtained by integrating the density of states up to the Fermi level.

[0073] According to the distribution of bond strength from the inside to the surface of the thick block, it was found that the bonding effect of the surface atoms of the (110) and (100) crystal planes was significantly weaker than that of the inside, while the bonding effect of the surface atoms of the (001) crystal plane was stronger than that of the inside. Therefore, it can be preliminarily determined that the (110) and (100) crystal planes can achieve two-dimensional morphological exfoliation.

[0074] The three characteristic crystal planes of wurtzite were step-stretched in the direction perpendicular to the crystal plane. The tiny atomic displacement of each stretch was Δd, and the Δd values were tested at 0.01nm, 0.1nm and 0.5nm respectively.

[0075] Based on the formula Draw the energy change curve during the peeling process, and according to E (i,1) and E (i,0)The critical point of crystal plane separation is determined by the relationship between the two planes and the position where the crystal plane separation occurs. It can be found that the position where the (110) and (100) crystal planes separate is in the surface area, and the two-dimensional morphology can be finally peeled off. However, the (001) crystal plane will break in the middle area during the stretching process, and the two-dimensional structure cannot be obtained. Figure 4 .

[0076] The energy of the instantaneous steady state obtained by each stretching Δd = 0.01 nm is summed or integrated until the critical point of interface separation, and the peeling energy data of the two-dimensional wurtzite structure are obtained, see Figure 5 For Δd = 0.1nm and 0.5nm, the energy curve becomes less smooth due to the relatively large stretching amplitude. In particular, for 0.5nm, the critical point is skipped, resulting in inaccurate results. Therefore, a suitable Δd value and sufficient intermediate instantaneous structures are particularly important to ensure accurate results.

[0077] The degree of interface reconstruction can be determined based on the numerical difference between the critical point and the final convergence state, that is, the decrease in the energy curve after the critical point. Figure 6 As shown in the figure, for common van der Waals crystals MoS2 and black phosphorus, the degree of interface coupling reconstruction after surface separation is very small due to weak interlayer interactions, resulting in a relatively low drop in the curve. However, for materials with strong interlayer interactions, such as Ca2N and wurtzite, the energy curve will drop significantly after the critical point. This is because after surface separation, the interface atoms will undergo a significant reconstruction, resulting in a redistribution of the bonding state wave function, which will reduce the system energy and maintain stability.

[0078] In summary, the present invention analyzes the symmetry of the crystal structure, divides the characteristic crystal planes of the structure, and then judges whether the crystal plane can be stripped into a two-dimensional form based on the atomic stacking mode and bonding type / strength of different crystal planes. The target crystal plane with relatively weak atomic bonding in the surface area is step-stretched, and a small atomic displacement is applied each time along the direction perpendicular to the crystal plane. Then, a rapid structural relaxation is performed, and the step-stretching is repeated until the crystal plane is separated, and finally a stable two-dimensional structure of the crystal plane is obtained. According to each instantaneous steady-state structure during the stripping process, the change in its bonding strength and the dynamic evolution image of the atomic orbital wave function coupling are output. The energy integral from the initial state to the critical point obtains the stripping energy data of the system. The energy integral from the critical point to the final stable state obtains the degree of interface coupling reconstruction. This method does not rely on a specific program. A series of commercial or open source software tools on the market can introduce this method to write corresponding modules to realize the calculation of the step-stripping process. The method can also be programmed into automated equipment such as robotic arms to achieve automated intelligent stripping of materials through in-situ crystal orientation characterization and real-time monitoring of mechanical signal conduction.

[0079] The embodiment of the present invention also provides a device for observing the two-dimensional morphology of crystal materials by stepping and peeling, such as Figure 7 As shown, the apparatus 700 includes a processor 701, and the processor 701 is configured to:

[0080] Obtain target crystal structure data file;

[0081] Analyzing the atomic stacking mode and bonding type of characteristic crystal planes according to the target crystal structure data file, and screening characteristic crystal planes with weak bonding interactions;

[0082] The step-by-step stretching is performed along the direction perpendicular to the crystal plane, and the step-by-step peeling process is described by the following formula (1):

[0083]

[0084] Where ΔE is the change in total energy of the system during stretching, E (i,0) Corresponding to the instantaneous initial state energy, E (i,1) is the instantaneous steady-state total energy after the crystal plane atoms are stretched by Δd displacement and the structure is relaxed, and A is the size area of the characteristic crystal plane;

[0085] The critical point of crystal plane separation is determined according to the output of formula (1). The energy change at the critical point of crystal plane separation satisfies the law E (i,1) ≤E (i,0) ;

[0086] The instantaneous energy of the entire step-by-step stripping process is summed or integrated until the critical point of interface separation to output the accurate stripping energy data E of the two-dimensional structure. C ;

[0087] The degree of interface reconstruction is judged based on the numerical difference of ΔE between the critical point and the final convergence state.

[0088] The processor 701 may be a processing device including one or more general-purpose processing devices, such as a microprocessor, a central processing unit (CPU), a graphics processing unit (GPU), etc. More specifically, the processor 701 may be a complex instruction set computing (CISC) microprocessor, a reduced instruction set computing (RISC) microprocessor, a very long instruction word (VLIW) microprocessor, a processor that runs other instruction sets, or a processor that runs a combination of instruction sets. The processor 701 may also be one or more special-purpose processing devices, such as an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), a digital signal processor (DSP), a system on a chip (SoC), etc. The processor 701 may be communicatively coupled to a memory and configured to execute computer-executable instructions stored thereon to execute the control method for observing the two-dimensional morphology step-peeling of the crystal material according to the above-mentioned embodiment.

[0089] In some embodiments, the processor is further configured to: obtain a target crystal structure data file through symmetry analysis and / or phase analysis.

[0090] In some embodiments, the processor is further configured to: divide according to the symmetry of the crystal structure, wherein each crystal plane is atomically paired according to the arrangement, and the strength of the crystal plane bonding interaction is judged by electronegativity, atomic radius, and bonding / antibonding interaction; and screen characteristic crystal planes with weak bonding interactions according to a preset interaction strength threshold.

[0091] In some embodiments, the processor is further configured to: determine each atomic displacement Δd according to a level of detail of the description of the exfoliation process during the step-by-step stretching along a direction perpendicular to the crystal plane.

[0092] In some embodiments, the processor is further configured to: determine the critical point of interface separation based on whether bond breaking occurs in the surface atoms, and insert multiple transient intermediate states in the process of determining the critical point of interface separation to avoid skipping the critical point due to sparse data.

[0093] In some embodiments, the processor is further configured to: predict whether the crystal can achieve two-dimensional morphological peeling by using the formula (1).

[0094] In some embodiments, the processor is further configured to analyze the change in bonding strength from the inside to the surface of a thick layer of the crystal, and if the surface bonding effect is lower than the internal bonding effect within a preset threshold range, it is determined that the crystal can achieve two-dimensional morphological peeling.

[0095] It should be noted that the device provided in the embodiment of the present invention and the method previously described belong to the same technical idea, have the same technical principles and technical effects, and will not be repeated here.

[0096] The above description is intended to be illustrative and not restrictive. For example, the above examples (or one or more schemes thereof) can be used in combination with each other. For example, a person of ordinary skill in the art may use other embodiments when reading the above description. In addition, in the above-mentioned specific embodiments, various features can be grouped together to simplify the present disclosure. This should not be interpreted as an intention that a disclosed feature that is not required to be protected is necessary for any claim. On the contrary, the subject matter of the present invention may be less than all the features of a specific disclosed embodiment. Thus, the following claims are incorporated into the specific embodiments as examples or embodiments, wherein each claim is independently a separate embodiment, and it is considered that these embodiments can be combined with each other in various combinations or arrangements. The scope of the present invention should be determined with reference to the appended claims and the full scope of equivalents to which these claims are entitled.

Claims

1. A method for observing the two-dimensional morphology of a crystal material by step-by-step peeling, characterized in that: The method comprises: Obtain target crystal structure data file; Analyzing the atomic stacking mode and bonding type of characteristic crystal planes according to the target crystal structure data file, and screening characteristic crystal planes with weak bonding interactions; The step-by-step stretching is performed along the direction perpendicular to the crystal plane, and the step-by-step peeling process is described by the following formula (1): Where ΔE is the change in the total energy of the system during the stretching process, which is obtained by summing the energies of a series of instantaneous states, E (i,0) Corresponding to the instantaneous initial state energy, E (i,1) is the instantaneous steady-state total energy after the crystal plane atoms are stretched by Δd displacement and the structure is relaxed, and A is the size area of the characteristic crystal plane; The critical point of crystal plane separation is determined according to the output of formula (1). The energy change at the critical point of crystal plane separation satisfies the law E (i,1) ≤E (i,0) ; The instantaneous energy of the entire step-by-step stripping process is summed or integrated until the critical point of interface separation to output the accurate stripping energy data E of the two-dimensional structure. C ; The degree of interface reconstruction is judged based on the numerical difference of ΔE between the critical point and the final convergence state.

2. The method for observing the two-dimensional morphology of a crystal material by step-by-step peeling according to claim 1, characterized in that: Obtain the target crystal structure data file through symmetry analysis and / or phase analysis.

3. The method for observing the two-dimensional morphology of a crystal material by step-by-step peeling according to claim 1, characterized in that: The step of analyzing the atomic stacking mode and bonding type of characteristic crystal planes according to the target crystal structure data file and screening characteristic crystal planes with weak bonding interactions specifically includes: Classification is based on the symmetry of the crystal structure, where each crystal plane is paired with atoms according to the arrangement, and the strength of the crystal plane bonding is determined by electronegativity, atomic radius, and bonding / antibonding interactions; According to the preset interaction strength threshold, characteristic crystal planes with weak bonding interactions are screened.

4. The method for observing the two-dimensional morphology of a crystal material by step-by-step peeling according to claim 1, characterized in that: During the step-by-step stretching process perpendicular to the crystal plane, the atomic displacement Δd is determined according to the level of detail of the description of the exfoliation process.

5. The method for observing the two-dimensional morphology of a crystal material by step-peeling according to claim 1, characterized in that: The step of summing or integrating the instantaneous energy of the entire step-stripping process until the critical point of interface separation specifically includes: The critical point of interface separation is determined based on whether the surface atoms have broken bonds. Multiple transient intermediate states are inserted in the process of determining the critical point of interface separation to avoid skipping the critical point due to sparse data.

6. The method for observing the two-dimensional morphology of a crystal material by step-by-step peeling according to claim 5, characterized in that: After performing step stretching in a direction perpendicular to the crystal plane and describing the step peeling process by formula (1), the method further includes: The formula (1) is used to predict whether the crystal can achieve two-dimensional morphology exfoliation.

7. The method for observing the two-dimensional morphology of a crystal material by step-by-step peeling according to claim 6, characterized in that: The method of predicting whether the crystal can achieve two-dimensional exfoliation by using the formula (1) specifically includes: By analyzing the change in bonding strength from the interior to the surface of a thick layer of crystal, if the surface bonding is lower than the internal bonding within a preset threshold range, it is determined that the crystal can achieve two-dimensional morphology peeling.

8. A device for observing the two-dimensional morphology of crystal materials by step-by-step peeling, characterized in that: The apparatus comprises a processor configured to: Obtain target crystal structure data file; Analyzing the atomic stacking mode and bonding type of characteristic crystal planes according to the target crystal structure data file, and screening characteristic crystal planes with weak bonding interactions; The step-by-step stretching is performed along the direction perpendicular to the crystal plane, and the step-by-step peeling process is described by the following formula (1): Where ΔE is the change in total energy of the system during stretching, E (i,0) Corresponding to the instantaneous initial state energy, E (i,1) is the instantaneous steady-state total energy after the crystal plane atoms are stretched by Δd displacement and the structure is relaxed, and A is the size area of the characteristic crystal plane; The critical point of crystal plane separation is determined according to the output of formula (1). The energy change at the critical point of crystal plane separation satisfies the law E (i,1) ≤E (i,0) ; The instantaneous energy of the entire step-by-step stripping process is summed or integrated until the critical point of interface separation to output the accurate stripping energy data E of the two-dimensional structure. C ; The degree of interface reconstruction is judged based on the numerical difference of ΔE between the critical point and the final convergence state.

9. A system for observing the two-dimensional morphology of crystalline materials by step-by-step peeling, characterized in that: The system comprises: memory for storing computer programs; A processor, configured to execute the computer program to implement the method according to any one of claims 1 to 7.

10. A readable storage medium, characterized in that: The readable storage medium stores one or more programs, and the one or more programs can be executed by one or more processors to implement the method according to any one of claims 1 to 7.

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