A moiré material based on a van der Waals stacked structure, a method for producing a moiré material based on a van der Waals stacked structure using a hypotaxy growth method, and an electronic element containing the moiré material based on the van der Waals stacked structure.

Abstract

The present invention provides a moiré material based on a van der Waals stacked structure, a method for producing a moiré material based on a van der Waals stacked structure using a hypotaxy growth method, and an electronic device containing a moiré material based on a van der Waals stacked structure. [Solution] The moiré material based on the van der Waals stacked structure according to this disclosure includes a multilayer thin film structure in which each layer has an independent crystal orientation and crystal structure in the vertical direction, and depending on the interlayer superposition angle, each layer has an interference fringe pattern that is identical or different from each other in the horizontal direction of the same plane, or exhibits an atomic rearrangement phenomenon within the same plane.

Description

Technical Field

[0001] The present invention relates to a moiré material based on a van der Waals heterostructure substrate, a method for manufacturing a moiré material based on a van der Waals stacked structure using a hypoxic growth method, and an electronic device including the moiré material of the van der Waals heterostructure substrate, etc.

[0002] This research was conducted with the support of the Samsung Future Technology Incubation Project.

Background Art

[0003] With the development and complexity of semiconductor technology, the demand for high-quality two-dimensional semiconductor materials with excellent electrical, thermal, and mechanical properties is increasing. To manufacture such two-dimensional semiconductor materials, the chemical vapor deposition (CVD) growth method is widely used. Researchers have focused on various attempts to manufacture two-dimensional semiconductor materials with reduced defects such as thickness control, improved particle size, and grain boundaries and vacancies using the CVD growth method.

[0004] Among them, the epitaxial growth method of growing a two-dimensional substance on a high-crystalline substrate has attracted attention. The epitaxial growth method is a technique that grows on a single-crystalline substrate and preserves the crystal orientation with the underlying substance, inducing the one-directional growth of particles. However, since the epitaxial growth method requires the thin film to be grown and the substrate to have a similar crystal structure and lattice constant, there are limitations in the selection of the substrate, and a process of transferring the grown substance to another substrate is necessary for application to the final device.

[0005] On the other hand, a moiré material manufactured by stacking two-dimensional substances so as to have a stacking angle has various quantum effects, so it is applicable to various quantum devices and has attracted great attention. However, currently, the production of moiré materials can only be carried out in units of exfoliated flakes, and physical stacking through a separate physical transfer process is required.

[0006] Furthermore, the production of moiré patterns by the physical stacking of exfoliated flakes has limitations in producing super-moiré patterns of three or more layers, stacking of different materials, and large-area moiré patterns. While the production of moiré materials by some chemical vapor deposition methods has been reported, the area is small (tens of micrometers), and since they are formed arbitrarily, it is impossible to control the stacking angle.

[0007] Therefore, there is still a demand for moiré materials based on van der Waals stacked structures that enable large-area growth with diverse combinations and stacking angles of high-quality two-dimensional materials, a method for manufacturing moiré materials based on van der Waals stacked structures using a hypotaxy growth method, and electronic devices containing said moiré materials based on van der Waals stacked structures. [Overview of the project] [Problems that the invention aims to solve]

[0008] The problem that the present invention aims to solve is to provide a moiré material based on a van der Waals stacked structure, which includes a multilayer thin film structure that has a desired number of layers, combination of materials, stacking angle, crystal orientation, crystal structure, and diverse periodic patterns in the in-plane direction, or exhibits atomic rearrangement phenomena, even in large area sizes independent of the substrate, and has a defect-free and uniform surface.

[0009] Another problem that the present invention aims to solve is to provide a method for producing moiré material based on a van der Waals stacked structure using a hypotaxy growth method.

[0010] Another problem that the present invention aims to solve is to provide an electronic element containing a moiré material based on the van der Waals stacked structure. [Means for solving the problem]

[0011] From one perspective, Each layer has an independent crystal orientation and crystal structure in the vertical direction. A van der Waals layered structure-based moiré material is provided, comprising a multilayer thin film structure having interference fringes that are identical or different in periodic patterns horizontally on one surface depending on the interlayer superposition angle, or exhibiting atomic rearrangement phenomena within one surface. The other aspect involves the step of forming a first raw material thin film layer on at least one surface of the substrate, The steps include: placing a two-dimensional crystalline first template on the first raw material thin film layer; The steps include supplying a second raw material-containing gas source onto a first raw material thin film layer on which the two-dimensional crystalline first template is placed, and performing a first heat treatment to form a crystalline first thin film layer containing the first and second raw materials, The steps include forming a third raw material thin film layer on the crystalline first thin film layer, The steps include: arranging a two-dimensional crystalline second template on the third raw material thin film layer at a twisted angle; A multilayer thin film structure is manufactured, comprising the steps of supplying a fourth raw material-containing gas supply source onto a third raw material thin film layer on which the two-dimensional crystalline second template is arranged, and performing a second heat treatment to form a crystalline second thin film layer containing the third and fourth raw materials. The crystalline first thin film layer and the crystalline second thin film layer are layers crystallized downward from the bottom of the two-dimensional crystalline first template and the two-dimensional crystalline second template, respectively, by hypotaxy growth. A method for producing moiré material on a van der Waals layered structure substrate using a hypotaxy growth method is provided.

[0012] Furthermore, another aspect provides an electronic device containing a moiré material based on the van der Waals stacked structure described above. [Effects of the Invention]

[0013] The moiré material based on the van der Waals stacked structure according to the present invention includes a multilayer thin film structure in which each layer has an independent crystal orientation and crystal structure in the vertical direction, and depending on the interlayer overlap angle, it has interference fringes of the same or different periodic patterns in the horizontal direction on the same plane, or exhibits atomic rearrangement phenomena within the same plane. The multilayer thin film structure has a uniform surface without defects, and can have a desired number of layers, combination of materials, stacking angle, crystal orientation, crystal structure, and in-plane direction, regardless of the substrate, even up to a large area size, and exhibits atomic rearrangement phenomena. Therefore, the moiré material based on the van der Waals stacked structure on one side can be applied to electronic devices and the like in various fields. [Brief explanation of the drawing]

[0014] [Figure 1] This is a schematic diagram illustrating the process by which a multilayer thin film structure of a moiré material based on a van der Waals stacked structure according to one embodiment is formed by controlling the angle using a hypotaxy growth mechanism. [Figure 2A] The left image shows the diffraction pattern of the MoS2 thin film surface deposited during the production of the thin film structure in Production Example 1 by supplying the reaction gas for 60 minutes, and the middle image shows the TEM image (intermediate) and diffraction pattern (right) of the MoS2 thin film surface after the first hypotaxy growth by supplying the reaction gas for 120 minutes. [Figure 2B] This shows the results of analyzing the crystallinity of the MoS2 thin film obtained in Manufacturing Example 1 using photoluminescence spectroscopy. [Figure 2C] This shows the results of analyzing the Raman spectra in the low-wavelength region (left) and high-wavelength region (right) when the number of layers of the MoS2 thin film obtained in Manufacturing Example 1 was increased to 2, 3, and 4 layers. [Figure 3] This is a schematic diagram showing the process by which a multilayer thin film structure of a moiré material based on a van der Waals stacked structure according to one embodiment is formed by controlling the angle using a large-area transfer device. [Figure 4]During the fabrication of the thin film structure of Example 1, after the first hypostaxy growth, a Mo thin film was partially deposited, and single-crystalline graphene second templates were arranged with twists of about 10° and about 30° respectively in the clockwise direction, and a schematic diagram, a selected area electron diffraction (SAED) pattern, and a transmission electron microscope (TEM) image of the MoS2 / MoS2 thin film structure after the second hypostaxy growth are shown. [Figure 5] A schematic diagram and a transmission electron microscope (TEM) image of a MoS2 moiré pattern fabricated with a large area of about 4 inches of the MoS2 / MoS2 thin film structure of Example 1 are shown. [Figure 6] Transmission electron microscope (TEM) images and schematic diagrams of MoS2 moiré patterns fabricated with a large area of several cm of the MoS2 / MoS2 thin film structures of Examples 2 - 7 are shown. [Figure 7A] Results of analyzing Raman spectra in the low wavelength region (left side) and the high wavelength region (right side) for the MoS2 single-crystalline thin film of Production Example 1, the MoS2 / MoS2 moiré thin film of Example 1, the MoS2 / 2L-MoS2 moiré thin film of Example 8, and the MoS2 / 3L-MoS2 moiré thin film of Example 9 are shown. [Figure 7B] Results of analyzing photoluminescence spectra for the MoS2 / MoS2 single-crystalline thin film of Example 1, the MoS2 / 2L-MoS2 moiré thin film of Example 8, the MoS2 / 3L-MoS2 moiré thin film of Example 9, and the MoS2 / 4L-MoS2 moiré thin film of Example 10 are shown. [Figure 8A] Results of analyzing Raman spectra in the low wavelength region for the MoS2 single-crystalline thin film of Production Example 1, the MoS2 / MoS2 thin film of Example 11, and the MoS2 / 2L-MoS2 thin film of Example 12 are shown. [Figure 8B] Results of analyzing a dark field transmission electron microscope (DF-TEM) for the MoS2 / MoS2 thin film of Example 11 are shown. [Figure 9A] Schematic diagrams, diffraction patterns, and transmission electron microscope (TEM) images showing the angles (or stacking angles) by which the MoS2 single-crystalline layers were twisted respectively in the clockwise direction during the second and third hypostaxy growths of Example 13 are shown. [Figure 9B] A schematic diagram showing the angles (or stacking angles) by which the MoS2 single crystal layers were each twisted in the clockwise direction during the second and third hypotaxy growths when manufacturing a MoS2 / MoS2 / MoS2 superlattice thin film structure of Example 14 over a large area of several centimeters, and optical microscope and transmission electron microscope images for the indicated regions (dotted box, solid line box). [Figure 10] A low magnification TEM image (middle) using false-color and a TEM image and diffraction pattern (right) of the enlarged indicated region for the surface of a MoS2 single crystal / MoS2 polycrystalline moiré domain thin film structure (left schematic diagram) of Example 15. [Figure 11A] A TEM image and diffraction pattern for the surface of a MoS2 / WS2 moiré thin film of Example 16. [Figure 11B] Results of analyzing the Raman spectrum in the high wavelength region for the surface of a MoS2 / WS2 moiré thin film of Example 16. [Figure 12] A schematic diagram of a field effect transistor (FET) according to one embodiment. [Figure 13] A schematic diagram of a field effect transistor (FET) according to another embodiment.

Embodiments for Carrying Out the Invention

[0015] Hereinafter, a moiré material based on a van der Waals stacked structure according to an embodiment of the present invention, a method for manufacturing a moiré material based on a van der Waals stacked structure using a hypotaxy growth method, and an electronic device including the moiré material based on the van der Waals stacked structure will be described in detail with reference to the accompanying drawings. The following are presented as examples and the present invention is not limited thereby. The present invention is defined only by the scope of the claims described later.

[0016] Hereinafter, the descriptions "upper" or "above" may include not only those directly above in contact but also those above without contact.

[0017] A singular expression includes multiple expressions unless the context clearly indicates otherwise. Furthermore, when a part "includes" a component, this does not exclude other components, unless otherwise stated.

[0018] In this specification, the term “combination” includes one or more of the components described above, unless otherwise specified. Terms such as 1, 2, 3, 4, 5, 6, 7 may be used to describe a variety of components, but components should not be limited by these terms. The terms are used solely for the purpose of distinguishing one component from others.

[0019] In this specification, "or" means "and / or" unless otherwise specified.

[0020] In this specification, the terms “about” or “substantially” include the value mentioned, as well as a value within an acceptable range of deviation from the specified value as determined by a person skilled in the art, taking into account the error associated with the measurement of the specified quantity (i.e., the limitations of the measuring system). For example, “about” or “substantially” may mean a value within one or more standard deviations, or a value within ±30%, ±20%, ±10%, or ±5% of the stated value.

[0021] Throughout this specification, the term "hypotaxy" is a compound word of "hypo," meaning "downward," and "taxy," meaning "arrangement," and refers to a state in which the crystalline structure of the template is aligned below the template.

[0022] Throughout this specification, the term “perpendicular” means perpendicular to a coplane and refers to the out-of-plane growth direction of a thin film.

[0023] Throughout this specification, the term “coplanar horizontal direction” means the in-plane growth direction of a thin film.

[0024] Throughout this specification, the term “van der Waals stacked structure” refers to both homostructures, which consist of stacked identical materials, and heterostructures, which consist of stacked different materials, each structure being linked by van der Waals forces.

[0025] Throughout this specification, the term "chalcogenide" means a compound composed of one or more Group 16 (chalcogen) elements and one or more cationic elements.

[0026] Throughout this specification, the term “diameter” is used when referring to a “circular shape,” but when referring to an “elliptical shape” it means the “long axis length,” and when referring to a “rectangular shape” it means the “long side length.”

[0027] Throughout this specification, the term "Moire pattern" means, in French, an interference fringe or wave pattern, and is also called a "Moire pattern," referring to a new pattern that appears when repeating simple patterns are superimposed, due to the interference between them caused by the difference in periodicity.

[0028] Throughout this specification, the term “Super-moire pattern” is also used for “Moire of moire pattern” and refers to a novel pattern revealed by the interference of two or more malaligned bilayer superlattices (pairs of 1-2 and 2-3 layers).

[0029] Throughout this specification, the term “critical angle” means an angle greater than 0° and less than 5°, an angle greater than 0° and less than 3°, or a near-zero angle.

[0030] Throughout this specification, the term “atomic rearrangement” refers to a phenomenon in which clusters of several nanometers in size, which are groups of atoms different from the original arrangement or number of atoms.

[0031] Throughout this specification, the terms “3-fold symmetry” or “6-fold symmetry” mean “120° rotational symmetry” or “60° rotational symmetry.”

[0032] Throughout this specification, the term “Moire domain” means “a region having interference fringes of the same period in the same horizontal plane.”

[0033] Throughout this specification, terms such as “one embodiment” mean that a particular element described in relation to an embodiment is included in at least one embodiment described herein, and may or may not be present in other embodiments. It should also be understood that the elements described herein can be combined in any suitable manner in a variety of embodiments. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which this application belongs. All patents, patent applications, and other references cited herein are incorporated in their entirety by reference. However, if any terminology in this specification conflicts with or contradicts any terminology in an incorporated reference, the terminology in this specification shall prevail over the conflicting terminology in the incorporated reference. While specific examples and embodiments have been described, the applicant or those skilled in the art may conceive of alternatives, modifications, variations, improvements, and substantial equivalents that are not currently anticipated or foreseeable. Therefore, the appended claims and amendments are intended to include all such alternatives, variations, improvements, and substantial equivalents.

[0034] When two two-dimensional material structures are stacked, the interference fringes created, which have different periodicities depending on the stacking angle, exhibit novel physical, chemical, and electrical properties different from those of existing stacked material structures. For example, the Moire excitation phenomenon was observed in a Moire pattern generated by stacking graphene and transition metal nichalcogenides (TMDs). It was demonstrated that the Moire pattern can tune the superconducting and Mott insulating states and exhibits a ferroelectric effect.

[0035] However, two-dimensional materials used as growth templates have problems with surface uniformity and large-area growth because they require transfer.

[0036] The inventors of this invention propose the following to utilize two-dimensional materials to produce high-quality moiré patterns over large areas using various stacking angles and material combinations, for application in various industrial fields.

[0037] A moiré material based on a van der Waals stacked structure according to one embodiment includes a multilayer thin film structure in which each layer has an independent crystal orientation and crystal structure in the vertical direction, and depending on the interlayer superposition angle, it has identical or different periodic interference fringe patterns in the horizontal direction of the same plane, or exhibits atomic rearrangement phenomena within the same plane. This is supported by evaluation examples 1 to 7 described later.

[0038] In one embodiment, the multilayer thin film structure consists of layers that are either identical or composed of different materials. This is supported by evaluation examples 3 and 8, which will be described later.

[0039] A multilayer thin film structure according to one embodiment may include a metal chalcogenide compound, a metal oxide, a metal or metalloid carbide compound, a metal or metalloid nitride compound, or a combination thereof.

[0040] For example, metal chalcogenide compounds may include compounds represented by the following chemical formula 1. [C1] MX2

[0041] In the above formula, M may be at least one metal or alloy selected from Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Rf, Db, Sg, Bh, Hs, Mt, Ds, Rg, Cn, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, and X may be at least one element selected from S, Se, Te.

[0042] For example, the compound represented by chemical formula 1 may include the compound represented by the following chemical formula 2. [C2] M'S2

[0043] In the above formula, M' may be a metal selected from Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Rf, Db, Sg, Bh, Hs, Mt, Ds, Rg, Cn, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, and Zr.

[0044] For example, the compound represented by chemical formula 1 may include MoS2, WS2, or a combination thereof.

[0045] For example, metal oxides may include transition metal oxides. Examples of transition metal oxides include, but are not limited to, MoO2, WO3, Sc2O3, TiO2, V2O5, Cr2O3, Mn3O4, Fe3O4, Co3O4, NiO, or CuO. Examples of metal or metalloid carbide compounds include, but are not limited to, Al4C3, Mo2C, SiC, WC, TiC, TaC, TiSiC, TaSiC, TiAlC, or TaAlC. Examples of metal or metalloid nitride compounds include, but are not limited to, AlN, GaN, InN, TiN, TaN, or SiN. On the other hand, multilayer thin film structures are also structures in which metal or metalloid carbide compounds and metal or metalloid nitride compounds are layered.

[0046] A multilayer thin-film structure according to one embodiment may have a crystalline structure independent of the crystalline or amorphous structure of the substrate. This is supported by Evaluation Example 4, which will be described later.

[0047] The diameter of the multilayer thin film structure according to one embodiment is 1 μm to 300 mm, but is not limited thereto. This is supported by Evaluation Example 3, which will be described later.

[0048] The periodic interference fringes of a multilayer thin-film structure according to one embodiment are moiré patterns, super-moiré patterns, or combinations thereof. This is supported by evaluation examples 3 and 6 described later.

[0049] When the interlayer superposition angle of a multilayer thin film structure according to one embodiment is a critical angle of 5° or less, atomic rearrangement phenomena can be observed within the same plane. This is supported by Evaluation Example 5, which will be described later.

[0050] According to one embodiment, it is possible to control the number of layers and the interlayer overlap angle of a multilayer thin film structure. This is supported by evaluation examples 2, 3, 4, and 6 described later.

[0051] A method for producing a moiré material based on a van der Waals stacked structure using a hypotaxy growth method according to one embodiment includes the steps of: forming a first raw material thin film layer on at least one surface of a substrate; placing a two-dimensional crystalline first template having defects on the first raw material thin film layer; supplying a second raw material-containing gas supply source onto the first raw material thin film layer on which the two-dimensional crystalline first template is placed, followed by a first heat treatment to form a first raw material and second raw material-containing crystalline first thin film layer; forming a third raw material thin film layer on the crystalline first thin film layer; and placing a two-dimensional crystal having defects on the third raw material thin film layer. The method includes the steps of twisting and positioning a second crystalline template at a predetermined angle, and supplying a fourth raw material-containing gas supply source onto a third raw material thin film layer on which the two-dimensional crystalline second template is positioned, followed by a second heat treatment to form a third raw material and a fourth raw material-containing crystalline second thin film layer, thereby manufacturing a multilayer thin film structure, wherein the first and second raw material-containing crystalline first thin film layer and the third and fourth raw material-containing crystalline second thin film layer are also layers whose crystals are oriented downward from the bottom of the two-dimensional crystalline first template and the two-dimensional crystalline second template, respectively, by a hypotaxy growth method.

[0052] One embodiment of a method for producing a moiré material based on a van der Waals stacked structure using hypotaxy growth allows for the formation of a moiré pattern with a uniform surface solely through synthesis using hypotaxy growth, which utilizes a two-dimensional crystalline template to induce downward alignment of crystal orientations. Furthermore, this embodiment can also form super-moiré patterns with a desired number of layers, combination of materials, and stacking angle. Moreover, this embodiment allows for the observation of atomic rearrangement phenomena that are difficult to observe during the synthesis process. Therefore, this embodiment can be used in a variety of application fields, such as the fabrication of large-area devices and device arrays.

[0053] Figure 1 is a schematic diagram illustrating the process by which a multilayer thin film structure of a moiré material based on a van der Waals stacked structure according to one embodiment is formed by controlling the angle using a hypotaxy growth mechanism.

[0054] Referring to Figure 1, a two-dimensional crystalline first template is placed on a substrate on which a first raw material thin film layer is arranged.

[0055] A substrate according to one embodiment may have a crystalline or amorphous structure. For example, the substrate may be SiO2 or SiO2 having an oxide film.

[0056] The first raw material thin film layer according to one embodiment is also a metal thin film layer or an alloy thin film layer. The metal thin film layer or alloy thin film layer may be one or more metals or alloys selected from Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Rf, Db, Sg, Bh, Hs, Mt, Ds, Rg, Cn, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr.

[0057] A two-dimensional crystalline first template according to one embodiment may include graphene, hexagonal boron nitride (hBN), transition metal chalcogen compounds, graphene oxide, metal oxides, black phosphorus, phosphorene, polymeric substances, or combinations thereof. Examples of polymeric substances include polymethyl tetraacrylate or polydimethylsiloxane.

[0058] A two-dimensional crystalline first template according to one embodiment has defects, which are also vacancies or nanopores.

[0059] In one embodiment, the defects in the two-dimensional crystalline first template are formed during or prior to the step of forming the crystalline first thin film layer.

[0060] The defects in the two-dimensional crystalline first template according to one embodiment may have nanopores with 3-fold symmetry or 6-fold symmetry. The size of the nanopores is not limited, but may be, for example, 10 nm or less, or 5 nm or less.

[0061] The first raw material thin film layer and the two-dimensional crystalline first template according to one embodiment may be formed by physical vapor deposition (PVD), thermal deposition, electron beam vacuum deposition, sputtering, chemical vapor deposition (CVD), or atomic layer deposition (ALD), but are not limited thereto.

[0062] A two-dimensional crystalline first template according to one embodiment may be directly formed on a first raw material thin film layer by the vapor deposition method described above, or it may be transferred and positioned on the first raw material thin film layer.

[0063] Next, a second raw material-containing gas supply source is supplied onto a first metal thin film layer on which a two-dimensional crystalline first template is placed, and a first heat treatment is performed to form a crystalline first thin film layer containing the first and second raw materials (first hypotaxy growth).

[0064] A second raw material-containing gas supply source according to one embodiment may contain one or more elements selected from S, Se, Te, C, N, and O. For example, the second raw material-containing gas supply source may contain H2S, H2Se, H2Te, CH4, N2, or O2.

[0065] In the step of forming a crystalline first thin film layer according to one embodiment, the first heat treatment may be performed at a temperature of 200°C to 1100°C for 5 minutes to 5 hours.

[0066] In one embodiment, the two-dimensional crystalline first template is a sacrificial template, and part or all of the sacrificial template may be removed.

[0067] The crystalline first thin film layer according to one embodiment may include MoS2, MoSe2, MoTe2, WS2, WSe2, WTe2, In2Se3, Cr2Se3, Sb2O3, MoO3, or a combination thereof.

[0068] The hypotaxy growth mechanism of a multilayer thin film structure according to one embodiment is described as follows.

[0069] In one embodiment, a crystalline first thin film layer can form nuclei (e.g., MoS2 nuclei) of compounds that form the first thin film layer beneath nanopores (e.g., 3-fold symmetry) which are defects in a two-dimensional crystalline first template. The crystal orientation of the nuclei is aligned with the crystal orientation of the two-dimensional crystalline first template by the defect edge of the template, and by continuously supplying a reaction gas, the nuclei can grow horizontally up to the center of the defect (basal plane) while maintaining their crystal structure. The continuous supply of the reaction gas expands the defect, thereby allowing horizontal growth within the first thin film layer. In this case, each nucleus formed in multiple defect areas is aligned with the same crystal orientation as the two-dimensional crystalline first template, and therefore, the resulting crystalline layer can be aligned with the same crystal orientation as the two-dimensional crystalline first template. Furthermore, by continuously supplying the reaction gas, a crystalline layer is formed that comes into contact with the bottom of the two-dimensional crystalline first template as described above, and growth of the formed crystalline layer downwards also occurs thereafter, ultimately resulting in the formation of a multilayer crystalline thin film aligned in the same crystal direction as the two-dimensional crystalline first template.

[0070] In other words, a crystalline first thin film layer according to one embodiment can be converted into a first crystalline thin film layer having the same crystal structure as the single-crystal or polycrystalline crystal structure at the bottom of a two-dimensional crystalline first template, regardless of the crystal structure of the substrate.

[0071] Next, a third raw material thin film layer is formed on the crystalline first thin film layer. The material, thickness, and formation method of the third raw material thin film layer are the same as those of the first raw material thin film layer described above, so their explanation is omitted here.

[0072] Next, a two-dimensional crystalline second template having defects is placed on the third raw material thin film layer at a twisted angle. The method for forming the two-dimensional crystalline second template having defects is the same as that for the two-dimensional crystalline second template described above, so it will not be explained here. To precisely control and position the two-dimensional crystalline second template on the third raw material thin film layer, the large-area transfer apparatus shown in Figure 3, which will be described later, is used. The large-area transfer apparatus shown in Figure 3 moves the stage to transfer the two-dimensional crystalline first and second templates onto the thin film structure, and the stage is rotatable, allowing for precise control of the two-dimensional crystalline second template at a desired angle.

[0073] For example, if the two-dimensional crystalline first and second templates are graphene and the crystalline first and second thin film layers are MoS2, referring to Figure 3, the graphene template / PMMA / PDMS structure is cut to the desired number of layers (e.g., two or more) to prepare it (Step 1). After moving a rotatable stage in the z-axis direction to attach the prepared graphene template / PMMA / PDMS structure onto the SiO2 / Mo thin film structure, the PMMA / PDMS is peeled off and the first hypotaxy growth is performed to produce the SiO2 / MoS2 thin film structure (Step 2). After rotating the rotatable stage to the desired angle, the prepared graphene template / PMMA / PDMS structure is attached, the PMMA / PDMS is peeled off and the second hypotaxy growth is performed to produce the MoS2 / MoS2 thin film structure having a moiré pattern (Steps 3-4).

[0074] Next, a multilayer thin film structure is manufactured by supplying a fourth raw material-containing gas source onto a third raw material thin film layer on which a two-dimensional crystalline second template is placed, and performing a second heat treatment to form a crystalline second thin film layer containing the third and fourth raw materials. The fourth raw material-containing gas source is the same as the second raw material-containing gas source, so its description is omitted here.

[0075] The crystalline first thin film layer and the crystalline second thin film layer described above are also layers whose crystals are oriented downward from the bottom of the two-dimensional crystalline first template and the two-dimensional crystalline second template, respectively, by a hypotaxy growth method.

[0076] Another embodiment provides an electronic device containing a moiré material based on a van der Waals stacked structure.

[0077] An electronic element according to one embodiment may be a field-effect transistor (FET), a memory element, a PN junction element, a neuromorphic element, an exciton element, or a quantum element. Such an electronic element can be applied to quantum computers, artificial intelligence, quantum communication, and the like.

[0078] Figure 12 is a schematic diagram of a field-effect transistor (FET) according to one embodiment.

[0079] In Figure 12, a silica substrate 112 is present on the substrate 111, and the multilayer thin film structure of the heterostructure described above is placed on top of it as a channel layer 113. Source electrodes 114 and drain electrodes 116 are present on the left and right sides, and a gate electrode 115 is present with an insulating layer 117 in between. Here, the current flowing between the source and drain electrodes 114 and 116 is controlled by applying a voltage to the gate electrode 115. That is, the multilayer thin film structure forms a channel region, and the current flowing between the source electrode 114 and the drain electrode 116 is controlled by the voltage applied to the gate electrode 115, thereby enabling on / off operation.

[0080] Figure 13 is a schematic diagram of a field-effect transistor (FET) according to another embodiment.

[0081] In Figure 13, the surface roughness of the silica substrate 112 and the dangling bonds allow for the placement of a buffer layer 118 between the channel layer 113 and the silica substrate 112 to control the scattering of charge during movement in the multilayer thin film structure of the heterostructure described above, i.e., the channel layer 113. The multilayer thin film structure can be further used as such a buffer layer.

[0082] In one or more embodiments, a buffer layer (not shown) is located between the channel layer 113 and the insulating layer 117 to improve injection efficiency, and the multilayer thin film structure may be used as such a buffer layer.

[0083] Another embodiment provides an optical element containing a moiré material based on a van der Waals stacked structure.

[0084] An optical element according to one embodiment is also a photodetector optical element having circular chirality.

[0085] Examples and comparative examples of the present invention are described below. However, the following examples are merely one embodiment of the present invention, and the present invention is not limited to these examples. [Examples]

[0086] Synthesis Example 1: Single-crystal graphene template

[0087] A single-crystal graphene template was synthesized by supplying methane and hydrogen gas at flow rates of 1 sccm and 100 sccm, respectively, onto a single-crystal copper foil (Alfa Aesar) under a vacuum using a CVD system, and heating at 1050°C for 30 minutes.

[0088] Synthesis Example 2: Polycrystalline Graphene Template

[0089] A polycrystalline graphene template was synthesized in the same manner as in Synthesis Example 1, except that methane and hydrogen gases were supplied at flow rates of 1 sccm and 100 sccm, respectively, onto a polycrystalline copper foil (Wieland) instead of a single-crystal copper foil.

[0090] Synthesis Example 3: Single-crystal graphene template / PMMA / PDMS structure

[0091] A single-crystal graphene template / PMMA / PDMS structure was fabricated by sequentially thinly coating a single-crystal graphene template produced in Synthesis Example 1 with polymethyl methacrylate (PMMA) and polydimethylsiloxane (PDMS), and then cutting the resulting structure into a predetermined number of pieces while it was fixed on a glass slide.

[0092] Synthesis Example 4: Polycrystalline Graphene Template / PMMA / PDMS Structure

[0093] Polycrystalline graphene template / PMMA / PDMS structures were fabricated in the same manner as in Synthesis Example 3, except that a polycrystalline graphene template manufactured in Synthesis Example 2 was used instead of the single-crystal graphene template manufactured in Synthesis Example 1.

[0094] Manufacturing Example 1: MoS2 single-crystal thin film structure produced by hypotaxy growth method

[0095] A MoS2 single-crystal thin film structure was fabricated using the hypotaxy growth method as follows.

[0096] A SiO2 substrate (thickness: 285 nm) with an oxide film was prepared. A Mo thin film was deposited onto the substrate using electron beam vacuum deposition, and a single-crystal graphene template manufactured in Synthesis Example 1 was transferred to prepare the sample. The prepared sample was placed in the reaction chamber of a vertical CVD system. The reaction chamber pressure was adjusted to 10⁻³ Torr to 760 Torr (atmospheric pressure). After raising the reaction chamber temperature to 1,000°C at a rate of 15°C / min, argon (Ar) gas and hydrogen sulfide (H₂S) gas were supplied at flow rates of 130 sccm and 20 sccm, respectively, to proceed with the reaction. After the reaction was completed after approximately 120 minutes, a MoS₂ single-crystal thin film structure was fabricated by depositing a MoS₂ single-crystal thin film on the SiO2 substrate with an oxide film.

[0097] Manufacturing Example 2: MoS2 Polycrystalline Thin Film Structure by Hypotaxy Growth Method

[0098] A MoS2 polycrystalline thin film structure was fabricated in the same manner as in Fabrication Example 1, except that the sample was prepared using a polycrystalline graphene template manufactured in Synthesis Example 2 instead of the single-crystal graphene template manufactured in Synthesis Example 1.

[0099] Example 1: MoS2 / MoS2 moiré thin film structure

[0100] A MoS2 / MoS2 moiré thin film structure was fabricated on a substrate in the order shown in Figure 3, as follows.

[0101] A SiO2 / Mo thin film structure was fabricated by depositing a Mo (molybdenum) thin film (thickness: approximately 0.3 nm) onto an SiO2 substrate (thickness: 285 nm) having an oxide film using electron beam vacuum deposition. The SiO2 / Mo thin film structure was placed on a rotatable stage and moved in the z-axis direction to deposit the single-crystal graphene template / PMMA / PDMS structure fabricated in Synthesis Example 3 onto the Mo thin film. The PMMA / PDMS was peeled off from the single-crystal graphene template structure to fabricate a SiO2 / Mo thin film / single-crystal graphene first template structure.

[0102] Using the fabricated structure as a sample, a MoS2 single-crystal thin film structure was fabricated using the hypotaxy growth method of Fabrication Example 1 (after the first hypotaxy growth).

[0103] Next, an SiO2 / MoS2 / Mo thin film structure was fabricated by depositing a Mo thin film (thickness: approximately 0.5 nm) onto a MoS2 single crystal thin film structure using electron beam vacuum deposition. The stage was rotated approximately 8° clockwise and moved along the z-axis to attach the single crystal graphene template / PMMA / PDMS structure fabricated in Synthesis Example 3. The PMMA / PDMS was peeled off the single crystal graphene template to fabricate an SiO2 / MoS2 / Mo thin film / single crystal graphene second template structure.

[0104] Using the manufactured structure as a sample, a MoS2 / MoS2 moiré thin film structure was fabricated on a substrate using the hypotaxy growth method of Manufacturing Example 1 (after the second hypotaxy growth).

[0105] Examples 2-7: MoS2 / MoS2 moiré thin film structures

[0106] After fabricating the SiO2 / MoS2 / Mo thin film structure, the MoS2 / MoS2 moiré thin film structure was fabricated in the same manner as in Example 1, except that the stage was rotated clockwise by approximately 9°, 10°, 12°, 14°, 20°, and 23° respectively, and moved along the z-axis to attach the single-crystal graphene template / PMMA / PDMS structure fabricated in Synthesis Example 3.

[0107] Example 8: MoS2 / 2LMoS2 Moire Thin Film Structure

[0108] An SiO2 / MoS2 / MoS2 / Mo thin film structure was fabricated by depositing a Mo thin film (thickness: approximately 0.8 nm) onto a MoS2 / MoS2 moiré thin film structure formed on a substrate manufactured in Example 1 using electron beam vacuum deposition. The stage was moved in the z-axis direction to deposit the single-crystal graphene template / PMMA / PDMS structure manufactured in Synthesis Example 3. The PMMA / PDMS was peeled off the single-crystal graphene template to fabricate an SiO2 / MoS2 / MoS2 / Mo thin film / single-crystal graphene third template structure.

[0109] Using the manufactured structure as a sample, a MoS2 / 2LMoS2 (where 2L means two layers) moiré thin film structure was fabricated on a substrate by the hypotaxy growth method of Manufacturing Example 1 (after the third hypotaxy growth).

[0110] Example 9: MoS2 / 3LMoS2 Moire Thin Film Structure

[0111] An SiO2 / MoS2 / 2LMoS2 / Mo thin film structure was fabricated by depositing a Mo thin film (thickness: approximately 1.1 nm) onto a MoS2 / 2LMoS2 (where 2L means two layers) moiré thin film structure formed on a substrate manufactured in Example 8 using electron beam vacuum deposition. The stage was moved in the z-axis direction to attach the single-crystal graphene template / PMMA / PDMS structure manufactured in Synthesis Example 3. The PMMA / PDMS was peeled off the single-crystal graphene template to fabricate an SiO2 / MoS2 / MoS2 / Mo thin film / single-crystal graphene fourth template structure.

[0112] Using the manufactured structure as a sample, a MoS2 / 3LMoS2 (where 3L means 3 layers) moiré thin film structure was fabricated on a substrate by the hypotaxy growth method of Manufacturing Example 1 (after the 4th hypotaxy growth).

[0113] Example 10: MoS2 / 4LMoS2 Moire Thin Film Structure

[0114] A SiO2 / MoS2 / 3LMoS2 / Mo thin film structure was fabricated by depositing a Mo thin film (thickness: approximately 1.4 nm) onto a MoS2 / 3LMoS2 (where 3L means 3 layers) moiré thin film structure formed on a substrate manufactured in Example 9, using electron beam vacuum deposition. The stage was moved in the z-axis direction to attach the single-crystal graphene template / PMMA / PDMS structure manufactured in Synthesis Example 3. The PMMA / PDMS was peeled off the single-crystal graphene template to fabricate a SiO2 / MoS2 / MoS2 / MoS2 / Mo thin film / single-crystal graphene fifth template structure.

[0115] Using the manufactured structure as a sample, a MoS2 / 4LMoS2 (where 4L is 4 layers) moiré thin film structure was fabricated on a substrate by the hypotaxy growth method of Manufacturing Example 1 (after the 5th hypotaxy growth).

[0116] Example 11: MoS2 / MoS2 thin film structure

[0117] After fabricating the SiO2 / MoS2 / Mo thin film structure, the stage was rotated clockwise by an angle of 0° to 2° (critical angle), and moved along the z-axis to attach the single-crystal graphene template / PMMA / PDMS structure fabricated in Synthesis Example 3, except that the MoS2 / MoS2 thin film structure was fabricated in the same manner as in Example 1 (after second hypotaxy growth).

[0118] Example 12: MoS2 / 2L-MoS2 thin film structure

[0119] An SiO2 / MoS2 / MoS2 / Mo thin film structure was fabricated by depositing a Mo thin film (thickness: approximately 0.5 nm) onto the MoS2 / MoS2 thin film structure produced in Example 11 using electron beam vacuum deposition. The stage was moved in the z-axis direction to deposit the single-crystal graphene template / PMMA / PDMS structure produced in Synthesis Example 3. The PMMA / PDMS was peeled off the single-crystal graphene template to fabricate an SiO2 / MoS2 / MoS2 / Mo thin film / single-crystal graphene third template structure.

[0120] Using the manufactured structure as a sample, a MoS2 / 2L-MoS2 (where 2L is two layers) thin film structure was fabricated on a substrate by the hypotaxy growth method of Manufacturing Example 1 (after the third hypotaxy growth).

[0121] Example 13: MoS2 / MoS2 / MoS2 Super Moire Thin Film Structure

[0122] Following the first hypotaxy growth in Example 1, an SiO2 / MoS2 / Mo thin film structure was fabricated by depositing a Mo thin film (thickness: approximately 0.5 nm) onto the SiO2 / MoS2 single crystal thin film structure using electron beam vacuum deposition. The stage was rotated approximately 15° clockwise and moved along the z-axis to attach the single crystal graphene template / PMMA / PDMS structure fabricated in Synthesis Example 3. The PMMA / PDMS was peeled off the single crystal graphene template to fabricate a second SiO2 / MoS2 / Mo thin film / single crystal graphene template structure.

[0123] Using the manufactured structure as a sample, a MoS2 / MoS2 moiré thin film structure was fabricated using the hypotaxy growth method of Manufacturing Example 1 (after the second hypotaxy growth).

[0124] Next, an SiO2 / MoS2 / MoS2 / Mo thin film structure was fabricated by depositing a Mo thin film (thickness: approximately 0.5 nm) onto a MoS2 / MoS2 moiré thin film structure using electron beam vacuum deposition. The stage was rotated approximately 30° further clockwise and moved along the z-axis to attach the single-crystal graphene template / PMMA / PDMS structure fabricated in Synthesis Example 3. The PMMA / PDMS was peeled off the single-crystal graphene template to fabricate an SiO2 / MoS2 / MoS2 / Mo thin film / single-crystal graphene third template structure.

[0125] Using the manufactured structure as a sample, a MoS2 / MoS2 / MoS2 super moiré thin film structure was fabricated on a substrate using the hypotaxy growth method of Manufacturing Example 1 (after the third hypotaxy growth).

[0126] Example 14: MoS2 / MoS2 / MoS2 Super Moire Thin Film Structure

[0127] After the first hypotaxy growth in Example 1, an SiO2 / MoS2 / Mo thin film structure was fabricated, and the stage was twisted clockwise by approximately 10° to produce a MoS2 / MoS2 moiré thin film structure using the hypotaxy growth method of Fabrication Example 1 (after the second hypotaxy growth).

[0128] Next, a MoS2 / MoS2 / MoS2 super moiré thin film structure was fabricated in the same manner as in Example 13, except that the SiO2 / MoS2 / MoS2 / Mo thin film structure was fabricated and the stage was further twisted clockwise by approximately 26° (after the third hypotaxy growth).

[0129] Example 15: MoS2 single crystal / MoS2 polycrystalline moiré domain thin film structure

[0130] Following the first hypotaxy growth in Example 1, an SiO2 / MoS2 / Mo thin film structure was fabricated by depositing a Mo thin film (thickness: approximately 0.5 nm) onto the SiO2 / MoS2 single crystal thin film structure using electron beam vacuum deposition. The stage was rotated approximately 15° clockwise and moved along the z-axis to attach the polycrystalline graphene template / PMMA / PDMS structure fabricated in Synthesis Example 4. The PMMA / PDMS was peeled off the polycrystalline graphene template to fabricate a second SiO2 / MoS2 single crystal / Mo thin film / polycrystalline graphene template structure.

[0131] Using the fabricated structure as a sample, a MoS2 single-crystal / MoS2 polycrystalline moiré domain thin-film structure was fabricated using the hypotaxy growth method of Fabrication Example 1 (after the second hypotaxy growth).

[0132] Example 16: MoS2 / WS2 Moire Thin Film Structure

[0133] In the first hypotaxy growth step of Example 1, instead of a Mo thin film, a W thin film (1 nm) was deposited to produce an SiO2 / WS2 single-crystal thin film structure, onto which a Mo thin film (thickness: approximately 1 nm) was deposited using electron beam vacuum deposition to produce an SiO2 / WS2 / Mo thin film structure. The stage was rotated approximately 11° clockwise and moved along the z-axis to attach the single-crystal graphene template / PMMA / PDMS structure produced in Synthesis Example 3. The PMMA / PDMS was peeled off the single-crystal graphene template to produce an SiO2 / WS2 / Mo thin film / single-crystal graphene second template structure.

[0134] Using the manufactured structure as a sample, a WS2 / MoS2 moiré thin film structure was fabricated on a substrate using the hypotaxy growth method of Manufacturing Example 1 (after the second hypotaxy growth).

[0135] Evaluation Example 1: MoS2 Thin Film Properties of Manufacturing Example 1 (1) - Single Crystal, Presence or Absence of Surface Defects

[0136] The MoS2 formation process in Production Example 1 was observed at different growth times. To confirm whether the thin film had single-crystal properties after the first hypotaxy growth, the reaction gas was supplied and the reaction was allowed to proceed for 60 minutes and 120 minutes. Diffraction patterns and transmission electron microscope (TEM) images of each MoS2 surface were captured. The results are shown in Figure 2A.

[0137] Figure 2A shows the diffraction pattern (left) of the MoS2 thin film surface deposited by supplying the reaction gas for 60 minutes during the production of the thin film structure of Production Example 1, and the TEM image (middle) and diffraction pattern (right) of the MoS2 thin film surface after the first hypotaxy growth by supplying the reaction gas for 120 minutes.

[0138] Referring to Figure 2A, in the MoS2 thin film deposited by supplying the reaction gas for 60 minutes from Fabrication Example 1, a portion of the graphene template was observed on the sample surface before the graphene template was completely removed. It was confirmed that the crystal orientation of all deposited MoS2 nuclei had a single-crystal structure that matched the graphene template.

[0139] Furthermore, in Production Example 1, the reaction gas was supplied for 120 minutes, and after the completion of the first hypotaxy growth, the TEM image of the MoS2 thin film surface showed no graphene template and was clean and defect-free.

[0140] The MoS2 thin film obtained in Fabrication Example 1 was a single-crystal layer identical to the graphene template and grew independently of the substrate structure. The graphene template on the MoS2 thin film in Fabrication Example 1 was spontaneously removed during the reaction.

[0141] Evaluation Example 2: MoS2 Thin Film Properties of Manufacturing Example 1 (2) - Crystallinity, Layer Number Control

[0142] The crystallinity of the MoS2 thin film obtained in Manufacturing Example 1 was analyzed by photoluminescence spectroscopy. The results are shown in Figure 2B.

[0143] Referring to Figure 2B, the MoS2 thin film obtained in Production Example 1 showed high crystallinity, exhibiting peaks with a narrow full width at half maximum and strong intensity in the energy range of 1.8 eV to 1.9 eV.

[0144] Furthermore, when the number of layers of the MoS2 thin film obtained in Manufacturing Example 1 was increased to 2, 3, and 4 layers, the Raman spectra in the low-wavelength region (left) and high-wavelength region (right) were analyzed. The results are shown in Figure 2C.

[0145] The Raman spectrum in the low-wavelength region (left side) shows the stacking method of the multilayer thin film structure and the stacking order of each layer material. Here, B represents breathing motion, and S represents shear motion. The Raman spectrum in the high-wavelength region (right side) shows the changes depending on the number of layers in the multilayer thin film structure. Here, the E12g mode shows a peak at approximately 382 cm⁻¹, and the A1g mode shows a peak at approximately 408 cm⁻¹.

[0146] Referring to Figure 2C, the Raman spectrum in the low-wavelength region (left side) shows that in the hypotaxy-grown MoS2 thin film of Fabrication Example 1, as the number of layers increased, the respiratory motion peak disappeared at approximately 41 cm⁻¹ and reappeared at approximately 12 cm⁻¹ (blue shift). In the hypotaxy-grown MoS2 thin film of Fabrication Example 1, as the number of layers increased, the shear motion peak disappeared at approximately 22 cm⁻¹ and reappeared at approximately 32 cm⁻¹ (red shift). The Raman spectrum in the high-wavelength region (right side) shows that in the hypotaxy-grown MoS2 thin film of Fabrication Example 1, as the number of layers increased, the distance between the E'2g mode and A1g mode peaks increased.

[0147] This confirmed that the MoS2 thin film obtained in Manufacturing Example 1 showed a change in the Raman spectrum with increasing number of layers, demonstrating that precise control of the number of layers is possible.

[0148] Evaluation Example 3: MoS2 Thin Film Characteristics of Examples 1-7 - Moire Pattern, Large Area Uniformity, Angle Control

[0149] During the fabrication of the thin film structure in Example 1, after the first hypotaxy growth, a Mo thin film was partially deposited and twisted clockwise by approximately 10° and 30° respectively to position a second single-crystal graphene template. Selected area electron diffraction (SAED) patterns and transmission electron microscope (TEM) images were then taken of the MoS2 / MoS2 thin film structure that underwent the second hypotaxy growth (schematic diagram on the left in Figure 4, dotted line). To confirm the crystal orientation of the MoS2 nuclei grown during the first hypotaxy growth and the MoS2 nuclei grown during the second hypotaxy growth, a portion of the graphene template was left in place during the second hypotaxy growth. The results are shown in Figure 4.

[0150] Referring to the SAED pattern in Figure 4, it was confirmed that the crystal orientation of the first MoS2 nucleus grown using the first hypotaxy process had a single-crystal structure that matched the graphene template. The crystal orientation of the second MoS2 nucleus grown using the second hypotaxy process was twisted approximately 10° clockwise, but it was also confirmed to have a single-crystal structure that matched the graphene template.

[0151] Referring to the transmission electron microscope (TEM) image in Figure 4, we confirmed that the boundary between the moiré pattern and the MoS2 single crystal was clearly defined through the cross-section of the dotted line portion of the second hypotaxy-grown MoS2 / MoS2 thin film structure. Furthermore, regardless of the twist angle, a clean moiré pattern and a surface with formed MoS2 single crystals were observed through the dotted line portion of the second hypotaxy-grown MoS2 / MoS2 thin film structure, free from polymer contamination or interlayer void formation.

[0152] Furthermore, transmission electron microscope (TEM) images of moiré patterns fabricated from the MoS2 / MoS2 thin film structures of Examples 1-7 over a large area of ​​approximately 4 inches or several centimeters were taken. The results are shown in Figures 5 and 6.

[0153] Figure 5 shows a schematic diagram and transmission electron microscope (TEM) image of the MoS2 moiré pattern fabricated over a large area of ​​approximately 4 inches using the MoS2 / MoS2 thin film structure of Example 1. Figure 6 shows the transmission electron microscope (TEM) image and schematic diagram of the MoS2 moiré pattern fabricated over a large area of ​​several centimeters using the MoS2 / MoS2 thin film structures of Examples 2 to 7.

[0154] Referring to Figures 5 and 6, even when fabricating the MoS2 / MoS2 thin film structures of Examples 1 to 7 over a large area, it is possible to form a uniform moiré pattern, and moiré patterns with diverse periods were confirmed.

[0155] This confirmed that the MoS2 / MoS2 thin film structure of Example 1 can produce a uniform moiré pattern over a large area through synthesis alone, without polymer contamination or bubble generation, achieving a level of uniformity that could not be obtained with conventional transfer-type moiré patterns. Through TEM images of the MoS2 / MoS2 thin film structures of Examples 2-7, it was confirmed that the interlayer stacking angle of MoS2 can be precisely controlled, and that moiré patterns, which are interference fringes with diverse periods depending on the angle, can be realized.

[0156] Evaluation Example 4: MoS2 Thin Film Characteristics of Examples 1, 8, 9, and 10 - Layer Number Control and Crystallinity of Second Hypotaxy Growth Substrate

[0157] The Raman spectra and photoluminescence spectra in the low-wavelength region (left) and high-wavelength region (right) were analyzed for the MoS2 single-crystal thin film of Production Example 1, the MoS2 / MoS2 moiré thin film of Example 1, the MoS2 / 2LMoS2 moiré thin film of Example 8, the MoS2 / 3LMoS2 moiré thin film of Example 9, and the MoS2 / 4LMoS2 moiré thin film of Example 10. The results are shown in Figures 7A and 7B, respectively.

[0158] Referring to Figure 7A, the MoS2 / MoS2 moiré thin films of Example 1, Example 8, and Example 9 showed deformed Raman spectra different from those of the MoS2 single-crystal thin film of Production Example 1. Specifically, the MoS2 / MoS2 moiré thin films of Example 1, Example 8, and Example 9 showed Raman spectral changes for second-hypotaxy grown MoS2, 2LMoS2, and 3LMoS2 (where L is the number of layers), respectively, regardless of the first-hypotaxy grown MoS2, and the distance between the peaks of the E12g mode and A1g mode increased with increasing number of layers.

[0159] Referring to Figure 7B, the MoS2 / MoS2 moiré thin film of Example 1, the Moiré MoS2 / 2LMoS2 thin film of Example 8, the MoS2 / 3LMoS2 moiré thin film of Example 9, and the MoS2 / 4LMoS2 moiré thin film of Example 10 all showed high crystallinity, exhibiting peaks with narrow full width at half maximum and strong intensity in the 1.8 eV to 1.9 eV energy range as the number of layers increased.

[0160] This confirmed that the MoS2 / MoS2 moiré thin films of Example 1, Example 8, Example 9, and Example 10, which have a moiré pattern, exhibit novel thin-film properties different from those of the MoS2 single-crystal thin film of Manufacturing Example 1.

[0161] Evaluation Example 5: MoS2 Thin Film Characteristics of Examples 11 and 12 - Atomic Rearrangement Phenomenon

[0162] The MoS2 single crystal thin film of Production Example 1, the MoS2 / MoS2 thin film of Example 11, and the MoS2 / 2LMoS2 thin film of Example 12 were analyzed using Raman spectra and dark-field transmission electron microscopy (DF-TEM) in the low-wavelength region. The results are shown in Figures 8A and 8B.

[0163] Referring to Figure 8A, the MoS2 / MoS2 thin film of Example 11 and the MoS2 / 2LMoS2 thin film of Example 12 showed deformed Raman spectra different from those of the MoS2 single crystal thin film of Production Example 1. Specifically, the MoS2 / 2LMoS2 thin film of Example 12 showed a 3R stacking order, unlike the MoS2 / MoS2 thin film of Example 11 (2H stacking order).

[0164] Referring to Figure 8B, the MoS2 / MoS2 thin film of Example 11 showed a more energetically stable atomic rearrangement phenomenon, with atoms moving and rearranging through the AB and BA domains at a small stacking angle.

[0165] Evaluation Example 6: Characteristics of MoS2 / MoS2 / MoS2 Thin Films of Examples 13-14 - Super Moire Pattern, Large Area Uniformity, Angle Control

[0166] Diffraction patterns, optical microscope images, and transmission electron microscope (TEM) images were taken for the MoS2 / MoS2 / MoS2 thin films of Example 13 or Example 14. The results are shown in Figures 9A and 9B.

[0167] Figure 9A shows a schematic diagram, diffraction pattern, and transmission electron microscope (TEM) image of the MoS2 single crystal layers twisted clockwise (or stacking angle) during the second and third hypotaxy growth of Example 13. Figure 9B shows a schematic diagram, optical microscope and transmission electron microscope images of the indicated areas (dotted box, solid box) during the second and third hypotaxy growth of the MoS2 / MoS2 / MoS2 single crystal thin film structure of Example 14, which was fabricated over a large area of ​​several cm.

[0168] Referring to Figures 9A and 9B, it was confirmed that the crystal orientation of the second hypotaxy-grown second MoS2 nuclei and the third hypotaxy-grown third MoS2 nuclei in Examples 13-14 was precisely controlled by twisting and stacking them clockwise, similar to the schematic diagram on the left, even when fabricating MoS2 / MoS2 / MoS2 thin films in a large-area structure. The MoS2 / MoS2 / MoS2 thin films of Examples 13-14 showed clean nm-scale supermoire patterns, moire patterns and supermoire patterns, or moire patterns, and surfaces on which MoS2 single crystals were formed, without polymer contamination or interlayer bubble formation.

[0169] Evaluation Example 7: Characteristics of MoS2 single crystal / polycrystalline thin film of Example 15 - Moiré domain

[0170] Low-magnification TEM images (intermediate) using false-color, and magnified TEM images and diffraction patterns (right) of the displayed area were taken from the surface of the MoS2 single crystal / MoS2 polycrystalline thin film structure of Example 15 (schematic diagram on the left). The results are shown in Figure 10.

[0171] Referring to Figure 10, the MoS2 single crystal / MoS2 polycrystalline thin film structure of Example 15 shows various moiré periods ranging from several nanometers to tens of nanometers in the horizontal or in-plane direction, and is shown in the form of moiré domains in which regions having the same moiré pattern of the same period are combined.

[0172] Evaluation Example 8: Characteristics of MoS2 / WS2 Thin Films in Example 16 - Single Crystal Layers of Heterogeneous Material Combinations

[0173] TEM images and diffraction patterns were taken from the surface of the MoS2 / WS2 thin film of Example 16, and the Raman spectra in the high-wavelength region were analyzed. The results are shown in Figures 11A and 11B.

[0174] Referring to Figures 11A and 11B, the MoS2 / WS2 thin film structure of Example 16 was a single-crystal layer of dissimilar materials, and like a single-crystal layer of the same material combination, it exhibited a clean, uniform moiré pattern and a deformed Raman spectrum.

[0175] A heterostructure including a multilayer thin film structure according to one embodiment can form a thin film with a new period by stacking two or more layers with different lattice periods, thus allowing for the tuning of quantum states. Examples of quantum states include superconductivity, magnetic twin states, and disordered electronic states through interlayer interactions of graphene at specific stacking angles. This allows for precise control of electron mobility, spin state, and coherence, making it applicable as a fundamental material in fields such as quantum computing and quantum communication. Such unique quantum mechanical properties of moiré patterns enable extremely precise control of materials and facilitate the development of new electronic devices on a nanoscale. For example, quantum points can be formed using moiré patterns, thereby realizing single-photon sources and qubits.

[0176] To aid in understanding the present invention, exemplary embodiments have been described and illustrated in the accompanying drawings. However, it should be understood that such embodiments are merely examples of the present invention and do not limit it. Furthermore, it should be understood that the present invention is not limited to what has been illustrated and described, as various other modifications are possible for those skilled in the art. [Explanation of Symbols]

[0177] 111 circuit board 112 Silica substrate 113 Channel Layers 114 Source electrodes 116 Drain electrode 115 Gate Shuttle 117 Insulator layer 118 Buffer Layers

Claims

1. A moiré material based on a van der Waals stacked structure, The structure includes a multilayer thin film structure in which each layer has an independent crystal orientation and crystal structure in the vertical direction. The multilayer thin film structure is a moiré material that, depending on the interlayer superposition angle, has interference fringes of the same or different periodic patterns in the horizontal direction of the same plane, or exhibits a phenomenon of atomic rearrangement within the same plane.

2. The moiré material according to claim 1, wherein the materials of each layer of the multilayer thin film structure are either the same as or different from each other.

3. The moiré material according to claim 1, wherein the multilayer thin film structure comprises a metal chalcogenide compound, a metal oxide, a metal or metalloid carbide compound, a metal or metalloid nitride compound, or any combination thereof.

4. The moiré material according to claim 1, wherein the multilayer thin film structure has a crystalline structure independent of the crystalline or amorphous structure of the substrate.

5. The moiré material according to claim 1, wherein the diameter of the multilayer thin film structure is in the range of 1 μm to 300 mm.

6. The moiré material according to claim 1, wherein the interference fringes of the periodic pattern of the multilayer thin film structure are a moiré pattern, a super moiré pattern, or a combination thereof.

7. The moiré material according to claim 1, wherein when the interlayer superposition angle of the multilayer thin film structure is a critical angle of 5° or less, a phenomenon of atomic rearrangement within the same plane is exhibited.

8. The moiré material according to claim 1, wherein the number of layers and the interlayer superposition angle of the multilayer thin film structure can be controlled.

9. A method for producing a moiré material based on a van der Waals stacked structure using a hypotaxy growth method, The steps include forming a first raw material thin film layer on at least one surface of the substrate, The steps include placing a two-dimensional crystalline first template on the first raw material thin film layer, The steps include: supplying a second raw material-containing gas supply source onto a first raw material thin film layer on which the two-dimensional crystalline first template is placed, followed by performing a first heat treatment to form a first raw material and second raw material-containing crystalline first thin film layer; The steps include forming a third raw material thin film layer on a crystalline first thin film layer containing the first and second raw materials, The steps include arranging a two-dimensional crystalline second template on the third raw material thin film layer at a twisted angle, The process includes the step of supplying a fourth raw material-containing gas supply source onto a third raw material thin film layer on which the two-dimensional crystalline second template is placed, followed by a second heat treatment to form a crystalline second thin film layer containing the third and fourth raw materials, thereby manufacturing a multilayer thin film structure. A manufacturing method wherein the first crystalline thin film layer containing the first and second raw materials and the second crystalline thin film layer containing the third and fourth raw materials are layers whose crystals are oriented downward from the bottom of the two-dimensional crystalline first template and the two-dimensional crystalline second template, respectively, by a hypotaxy growth method.

10. The manufacturing method according to claim 9, wherein the substrate has a crystalline structure or an amorphous structure.

11. The manufacturing method according to claim 9, wherein the first raw material thin film layer and the third raw material thin film layer contain one or more metals or alloys selected from Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Rf, Db, Sg, Bh, Hs, Mt, Ds, Rg, Cn, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, and Zr.

12. The manufacturing method according to claim 9, wherein the second raw material-containing gas supply source and the fourth raw material-containing gas supply source contain one or more elements selected from S, Se, Te, C, N, and O.

13. The manufacturing method according to claim 9, wherein the two-dimensional crystalline first template and the two-dimensional crystalline second template include graphene, hexagonal boron nitride (hBN), transition metal chalcogen compounds, graphene oxide, metal oxides, black phosphorus, phospholene, polymeric substances, or any combination thereof.

14. The manufacturing method according to claim 9, wherein the defects of the two-dimensional crystalline first template and the two-dimensional crystalline second template have nanopores with 3-fold or 6-fold symmetry.

15. The two-dimensional crystalline first template and the two-dimensional crystalline second template are sacrificial templates. A method for producing a moiré substance according to claim 9, wherein some or all of the sacrificial template is removed.

16. The manufacturing method according to claim 9, wherein the step of arranging the two-dimensional crystalline first template or the two-dimensional crystalline second template is a step of directly forming or transferring the two-dimensional crystalline first template or the two-dimensional crystalline second template onto the first raw material thin film layer or the third raw material thin film layer.

17. The manufacturing method according to claim 9, wherein the first heat treatment and the second heat treatment are each performed at a temperature in the range of 200°C to 1100°C for 5 minutes to 5 hours.

18. The crystalline first thin film layer and the crystalline second thin film layer are MoS ２ , MoSe ２ , MoTe ２ , WS ２ , WSe ２ , WTe ２ , In ２ Se ３ , Cr ２ Se ３ , Sb ２ O ３ , MoO ３ , or any combination thereof, the manufacturing method according to claim 9.

19. The manufacturing method according to claim 9, wherein the diameter of the multilayer thin film structure is in the range of 1 μm to 300 mm.

20. The aforementioned multilayer thin film structure is Each layer has an independent crystal orientation and crystal structure in the vertical direction. The manufacturing method according to claim 9, wherein, depending on the interlayer superposition angle, the materials have interference fringes of the same or different periodic patterns in the horizontal direction of the same plane, or exhibit an atomic rearrangement phenomenon within the same plane.

21. The manufacturing method according to claim 20, wherein the interference fringes of the periodic pattern of the multilayer thin film structure are a moiré pattern, a super moiré pattern, or a combination thereof.

22. The manufacturing method according to claim 20, wherein when the interlayer superposition angle of the multilayer thin film structure is a critical angle of 5° or less, an atomic rearrangement phenomenon is exhibited within the same plane.

23. The manufacturing method according to claim 20, wherein the number of layers of the multilayer thin film structure and the interlayer overlap angle can be controlled.

24. An electronic element comprising a moiré material based on a van der Waals stacked structure as described in any one of claims 1 to 8.

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