Graphene transfer method based on nanoimprint lithography

Abstract

The invention discloses a graphene transfer method based on nanoimprint. The method comprises the following steps: obtaining a photoresist layer / micro-nano structure layer / organic layer composite structure; covering the graphene layer with the photoresist / micro-nano structure layer / organic layer composite structure, and performing nano-imprinting; stripping the metal substrate to obtain an organic layer / micro-nano structure layer / photoresist layer / graphene layer composite structure; the surface of the substrate is covered with the organic layer / micro-nano structure layer / photoresist layer / graphene layer composite structure, so that the graphene layer is attached to the substrate, nano-imprinting is carried out, and the photoresist layer is cured in the nano-imprinting process; and stripping the organic layer / micro-nano structure layer / photoresist layer composite structure to obtain the graphene layer transferred to the substrate. The contact area between the micro-nano structure layer and the photoresist layer is increased through the micro-nano structure layer, the binding force between the organic layer and the photoresist layer is further increased, large-area graphene layer transfer is achieved based on nanoimprint, and the transfer quality is guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of two-dimensional carbon materials, and in particular relates to a graphene transfer method based on nanoimprinting. Background Art

[0002] CVD (chemical vapor deposition) is currently the mainstream method for preparing high-quality, large-area graphene materials. Graphene films grow on the surface of copper foil. In order to achieve the characterization, application and device preparation of graphene films, it is often necessary to transfer graphene films from copper foil to various target substrate surfaces such as quartz, silicon wafers, PET, silicon oxide, etc. In order to ensure the material properties of graphene, it must be transferred cleanly, completely and smoothly, that is, the transfer operation will not cause the graphene sheets to break, wrinkle or residual organic pollution.

[0003] Currently, the large-area transfer of graphene on metal foil substrates mainly adopts the "wet etching" transfer method. However, in the "wet etching" transfer method, after the etched graphene is transferred to the target substrate, liquid will remain between the graphene surface and the substrate, and water molecules will contaminate the graphene.

[0004] Therefore, in view of the above technical problems, it is necessary to provide a graphene transfer method based on nanoimprinting. Summary of the invention

[0005] The object of the present invention is to provide a graphene transfer method based on nanoimprinting, which can realize large-area and clean graphene transfer through nanoimprinting.

[0006] In order to achieve the above object, a technical solution provided by a specific embodiment of the present invention is as follows:

[0007] A graphene transfer method based on nanoimprinting, the method comprising:

[0008] Providing a substrate, the substrate comprising an organic layer and a micro-nano structure layer located above the organic layer, the micro-nano structure layer comprising spaced micro-nano units;

[0009] Applying photoresist on the micro-nano structure layer to obtain a photoresist layer / micro-nano structure layer / organic layer composite structure;

[0010] Covering the composite structure of photoresist / micro-nanostructure layer / organic layer on the graphene layer directly grown on the metal substrate and performing nanoimprinting to bond the graphene layer to the photoresist layer;

[0011] The metal substrate is peeled off to obtain a composite structure of organic layer / micro-nano structure layer / photoresist layer / graphene layer;

[0012] Covering the composite structure of organic layer / micro-nano structure layer / photoresist layer / graphene layer on the surface of the substrate so that the graphene layer and the substrate are bonded and nano-imprinting is performed, and curing the photoresist layer during the nano-imprinting process;

[0013] The organic layer / micro-nano structure layer / photoresist layer composite structure is peeled off to obtain a graphene layer transferred to the substrate.

[0014] In one or more embodiments of the present invention, the method for preparing the micro-nano structure layer includes:

[0015] Spin-coating a nanoimprint glue on the surface of the organic layer, and allowing the nanoimprint glue to form a deposited glue layer on the surface of the organic layer;

[0016] Providing a corresponding nanoimprint template, and aligning the nanoimprint template with the organic layer formed with the stacking glue layer for imprinting;

[0017] After curing, the mold is demoulded to obtain a micro-nano structure layer on the surface of the organic layer.

[0018] In one or more embodiments of the present invention, the micro-nano unit comprises a columnar micro-nano unit, and the columnar micro-nano units are distributed in an array; or,

[0019] The micro-nano units include wire-grid-shaped micro-nano units, and the wire-grid-shaped micro-nano units are distributed at intervals along a first direction.

[0020] In one or more embodiments of the present invention, when the micro-nano unit is a columnar micro-nano unit, the height of the columnar micro-nano unit is greater than or equal to 1 μm, and the cross-sectional diameter of the columnar micro-nano unit is 500 nm to 1 μm;

[0021] When the micro-nano unit is a wire-grid micro-nano unit, the height of the wire-grid micro-nano unit is greater than or equal to 1 μm, the width of the wire-grid micro-nano unit along the first direction is 500 nm to 1 μm, and the duty cycle of the wire-grid micro-nano unit is 50%.

[0022] In one or more embodiments of the present invention, the material of the photoresist layer is fluorinated modified acrylic resin.

[0023] In one or more embodiments of the present invention, the thickness of the photoresist layer between two adjacent micro-nano units is 2-3 μm; and / or,

[0024] The ratio of the height of the micro-nano unit to the thickness of the photoresist layer between two adjacent micro-nano units is 1:2 to 1:3.

[0025] In one or more embodiments of the present invention, the material of the organic layer is polycarbonate.

[0026] In one or more embodiments of the present invention, when the photoresist / micro-nanostructure layer / organic layer composite structure is covered on the graphene layer directly grown on the metal substrate and nanoimprinting is performed, the temperature of the nanoimprinting is 90°C to 150°C, the pressure of the nanoimprinting is 15 bar to 30 bar, and the time of the nanoimprinting is 120s to 300s.

[0027] In one or more embodiments of the present invention, when the organic layer / micro-nanostructure layer / photoresist layer / graphene layer composite structure is covered on the surface of the substrate to make the graphene layer adhere to the substrate and perform nanoimprinting, the temperature of nanoimprinting is 90°C to 150°C, the pressure of nanoimprinting is 15 bar to 30 bar, the time of nanoimprinting is 60s to 300s, and the photoresist layer is ultraviolet cured for at least 30s during the nanoimprinting process.

[0028] In one or more embodiments of the present invention, the material of the substrate is one of silicon and silicon oxide; and / or,

[0029] The metal substrate includes copper foil.

[0030] Compared with the prior art, the graphene transfer method based on nanoimprinting of the present invention increases the contact area between the micro-nano structure layer and the photoresist layer through the micro-nano structure layer, thereby increasing the bonding force between the organic layer and the photoresist layer, realizing the transfer of a large-area graphene layer and ensuring the transfer quality;

[0031] By breaking the bond between the nanoimprint graphene layer and the photoresist layer, it is avoided that the photoresist layer remains on the surface after the graphene layer is transferred, and it is also avoided that the graphene layer is transferred away by the composite structure of the organic layer / micro-nano structure layer / photoresist layer during the stripping process;

[0032] The transferred graphene layer of the present invention is clean, complete and defect-free, and can prevent the graphene layer from being contaminated by water molecules. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0034] Figure 1 This is a flow chart of a graphene transfer method based on nanoimprinting in Example 1 of the present invention;

[0035] Figure 2 Schematic diagram of the structure of the micro-nano structure layer in Example 1 of the present invention;

[0036] Figure 3 A partial top view of the micro-nano structure layer in Example 1 of the present invention;

[0037] Figure 4 Schematic diagram of the structure of the micro-nano structure layer in Example 1 of the present invention;

[0038] Figure 5 is a structural diagram of a micro-nano structure layer and a photoresist layer in Example 1 of the present invention;

[0039] Figure 6 is a structural diagram of a substrate in Example 2 of the present invention;

[0040] Figure 7 This is a diagram showing the composite structure change of the graphene transfer method based on nanoimprinting in Example 2 of the present invention;

[0041] Figure 8 This is a diagram showing the composite structure change of the graphene transfer method based on nanoimprinting in Example 2 of the present invention;

[0042] Fig. 9 This is a diagram showing the composite structure change of the graphene transfer method based on nanoimprinting in Example 2 of the present invention;

[0043] Fig.10 This is a diagram showing the composite structure change of the graphene transfer method based on nanoimprinting in Example 2 of the present invention;

[0044] Fig.11 This is a diagram showing the composite structure change of the graphene transfer method based on nanoimprinting in Example 2 of the present invention;

[0045] Fig.12 This is a Raman spectrum of the graphene layer in Example 2 of the present invention. DETAILED DESCRIPTION

[0046] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0047] Unless explicitly stated otherwise, throughout the specification and claims, the term “comprise” or variations such as “include” or “comprising”, etc., will be understood to include the stated elements or components but not to exclude other elements or components.

[0048] "Coupled" or "connected" or "connected" in the specification includes both direct connection and indirect connection. Indirect connection is a connection through an intermediate medium, such as a connection through an electrically conductive medium, which may have parasitic inductance or parasitic capacitance; indirect connection may also include connection through other active or passive devices on the basis of achieving the same or similar functional purposes, such as connection through circuits or components such as switches and follower circuits. In addition, in the present invention, words such as "first" and "second" are mainly used to distinguish one technical feature from another technical feature, and do not necessarily require or imply that there is a certain actual relationship, quantity or order between these technical features.

[0049] In the detailed description of the specification, reference is made to the accompanying drawings forming a part thereof, wherein like reference numerals refer to like parts throughout, and wherein are shown by way of exemplary embodiments that may be implemented. It should be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present disclosure. Therefore, the following detailed description should not be considered in a limiting sense.

[0050] The various operations in the specification may be described in turn as multiple discrete actions or operations in a manner that is most helpful in understanding the claimed subject matter. However, the order of description should not be interpreted as implying that these operations must be order-dependent. Specifically, these operations may not be performed in the order presented. The described operations may be performed in an order different from the described embodiments. Various additional operations may be performed and / or the described operations may be omitted in additional embodiments.

[0051] For purposes of this disclosure, the phrase "A and / or B" means (A), (B), or (A and B). For purposes of this disclosure, the phrase "A, B and / or C" means (A), (B), (C), (A and B), (A and C), (B and C), or (A, B and C).

[0052] Various components and devices may be referred to or shown in the singular form in this document (for example, "MOS tube", "transistor", "switch", etc.), but this is only for convenience of discussion, and any element mentioned in the singular form may include multiple such elements according to the teachings of this document.

[0053] The specification describes the use of the phrases "in this embodiment" or "in other embodiments" or "in some embodiments", which can each refer to one or more of the same or different embodiments. In addition, the terms "including", "comprising", "having", etc. used in relation to the embodiments of the present disclosure are synonymous.

[0054] Embodiment 1:

[0055] like Figure 1As shown, this embodiment provides a graphene transfer method based on nanoimprinting, the method comprising:

[0056] S10, providing a substrate, the substrate comprising an organic layer and a micro-nano structure layer located above the organic layer, the micro-nano structure layer comprising spaced micro-nano units;

[0057] S20, coating a photoresist on the micro-nano structure layer to obtain a composite structure of a photoresist layer / micro-nano structure layer / organic layer;

[0058] S30, covering the photoresist / micro-nanostructure layer / organic layer composite structure on the graphene layer directly grown on the metal substrate and performing nanoimprinting to bond the graphene layer to the photoresist layer;

[0059] S40, peeling off the metal substrate to obtain an organic layer / micro-nano structure layer / photoresist layer / graphene layer composite structure;

[0060] S50, covering the composite structure of organic layer / micro-nano structure layer / photoresist layer / graphene layer on the surface of the substrate so that the graphene layer and the substrate are bonded and nano-imprinting is performed, and curing the photoresist layer during the nano-imprinting process;

[0061] S60, peeling off the organic layer / micro-nano structure layer / photoresist layer composite structure to obtain a graphene layer transferred to the substrate.

[0062] Furthermore, in this embodiment, the surface area of ​​the metal substrate and the graphene layer is smaller than the surface area of ​​other layer structures, so as to ensure that the graphene layer can be transferred all at once and avoid waste of the graphene layer.

[0063] Furthermore, in one embodiment, a method for preparing the micro-nano structure layer includes:

[0064] S101, spin coating a nanoimprint adhesive on the surface of the organic layer, and allowing the nanoimprint adhesive to form a deposited adhesive layer on the surface of the organic layer;

[0065] S102, providing a corresponding nanoimprint template, and aligning the nanoimprint template with the organic layer formed with the buildup glue layer for imprinting;

[0066] S103, demoulding after curing to obtain a micro-nano structure layer on the surface of the organic layer.

[0067] Furthermore, the material of the organic layer in this embodiment is polycarbonate, that is, the organic layer is a polycarbonate layer, and the material of the photoresist layer in one embodiment is fluorinated modified acrylic resin, that is, the photoresist layer is a fluorinated modified acrylic resin layer.

[0068] Further, the micro-nano structure layer in this embodiment includes spaced micro-nano units, the duty cycle of the micro-nano units is 50%, and the height of the micro-nano units is greater than or equal to 1 μm. It can be understood that the micro-nano structure layer is embossed on the polycarbonate layer, and the structural features of the micro-nano structure layer increase the contact area between the micro-nano structure layer and the fluorinated modified acrylic resin layer, thereby increasing the bonding force between the polycarbonate layer and the fluorinated modified acrylic resin layer.

[0069] like Figure 2 and Figure 3 As shown, the micro-nano structure layer 20 in one embodiment includes columnar micro-nano units 21 distributed in an array. Further, the height H1 of the columnar micro-nano unit 21 is greater than or equal to 1 μm, the cross-sectional diameter W1 of the columnar micro-nano unit 21 is 500 nm to 1 μm, and the duty cycle of the columnar micro-nano unit is 50%, that is, the cross-sectional diameter W1 of the columnar micro-nano unit is equal to the distance W2 between two adjacent columnar micro-nano units 21 (and Figure 3 As shown in W2'), for example, the cross-sectional diameter W1 of the columnar micro-nano unit is 700 nm, then the distance W2 (and Figure 3 W2') is shown to be 700nm.

[0070] like Figure 4 As shown, the micro-nano structure layer 30 in one embodiment includes wire-grid-shaped micro-nano units 31 distributed at intervals along the first direction A. Further, the height H2 of the wire-grid-shaped micro-nano unit 31 is greater than or equal to 1 μm, the width W3 of the wire-grid-shaped micro-nano unit 31 along the first direction A is 500nm-1μm, and the duty cycle of the wire-grid-shaped micro-nano unit 31 is 50%, that is, the width W3 of the wire-grid-shaped micro-nano unit 31 along the first direction A is equal to the distance W4 between two adjacent wire-grid-shaped micro-nano units 31. For example, if the width W3 of the wire-grid-shaped micro-nano unit 31 along the first direction A is 600nm, then the distance W4 between two adjacent wire-grid-shaped micro-nano units 31 is 600nm.

[0071] like Figure 5 As shown, when the photoresist is coated on the micro-nano structure layer, the photoresist at least covers all the micro-nano units, that is, the photoresist completely fills the spaces between the micro-nano units.

[0072] In one embodiment, the thickness h1 of the photoresist layer 40 between two adjacent micro-nano units is 2-3 μm, and the ratio of the height of the micro-nano unit 31 to the thickness h1 of the photoresist layer 40 between two adjacent micro-nano units is 1:2-1:3. The thickness h2 of the photoresist layer 40 on the surface of the micro-nano unit is greater than 0.

[0073] The thickness h1 of the photoresist layer 40 between two adjacent micro-nano units refers to the distance between the first surface f1 and the second surface f2 of the photoresist layer, wherein the second surface f2 refers to the contact surface between the photoresist layer 40 and the two adjacent micro-nano units. The thickness h2 of the photoresist layer 40 on the surface of the micro-nano unit refers to the distance between the first surface f1 and the third surface f3 of the photoresist layer, wherein the third surface f3 refers to the contact surface between the photoresist layer and the upper surface of the micro-nano unit 31.

[0074] Exemplarily, the height H2 of the wire grid micro-nano unit 31 is 1 μm, and the thickness h1 of the photoresist layer 40 between two adjacent wire grid micro-nano units 31 is 2 to 3 μm. Another exemplary embodiment, the height H1 of the columnar micro-nano unit 21 is 1.2 μm, and the thickness h1 of the photoresist layer 40 between two adjacent columnar micro-nano units 21 is 2.4 to 3.6 μm.

[0075] In one embodiment, when the photoresist / micro-nanostructure layer / organic layer composite structure is covered on the graphene layer directly grown on the metal substrate and nano-imprinted, the temperature of the nano-imprinting is 90° C. to 150° C., the pressure of the nano-imprinting is 15 bar to 30 bar, and the time of the nano-imprinting is 120 s to 300 s. Through the above nano-imprinting, the graphene layer adheres to the fluorinated modified acrylic resin layer and generates a bond. The metal substrate in this embodiment includes copper foil.

[0076] In one embodiment, when the composite structure of organic layer / micro-nano structure layer / photoresist layer / graphene layer is covered on the surface of the substrate so that the graphene layer is attached to the substrate and nanoimprinting is performed, the temperature of nanoimprinting is 90°C to 150°C, the pressure of nanoimprinting is 15bar to 30bar, the time of nanoimprinting is 60s to 300s, and the photoresist layer is ultraviolet-cured during the nanoimprinting process, and the ultraviolet curing time is at least 30s. Through the above nanoimprinting, the fluorinated modified acrylic resin layer is cured under ultraviolet light and undergoes a polycondensation reaction, the bond between the graphene layer and the fluorinated modified acrylic resin layer is broken, and the graphene layer is transferred to the substrate. The material of the substrate in this embodiment is one of silicon and silicon oxide.

[0077] Embodiment 2:

[0078] This embodiment provides a graphene transfer method based on nanoimprinting, the method comprising:

[0079] like Figure 6As shown, a substrate C1 is provided, and the substrate C1 includes an organic layer 10 and a micro-nano structure layer 30 located above the organic layer 10. Specifically, the organic layer 10 is an 8-inch circular polycarbonate layer, and a nano-imprinting glue is spin-coated on the surface of the polycarbonate layer 10, and then the micro-nano structure layer 30 is nano-imprinted and cured, wherein the micro-nano structure layer 30 in this embodiment includes wire-grid-shaped micro-nano units 31 distributed at intervals along a first direction A, and each wire-grid-shaped micro-nano unit 31 has a width of 1 μm and a height of 1 μm.

[0080] like Figure 7 As shown, a photoresist 40 is coated on the micro-nano structure layer 30 to obtain a photoresist layer / micro-nano structure layer / organic layer composite structure C2. The material of the photoresist layer 40 in this embodiment is a fluorinated modified acrylic resin. Specifically, the fluorinated modified acrylic resin is spin-coated on the upper surface of the micro-nano structure layer 30, and the rotation speed during the spin coating process is 3000 rpm. After spin coating, the thickness h1 of the fluorinated modified acrylic resin layer 40 between two adjacent wire grid-shaped micro-nano units 31 is 3 μm.

[0081] like Figure 8 As shown, the photoresist / micro-nano structure layer / organic layer composite structure C2 is covered on the graphene layer 50 directly grown on the metal substrate 60 and nano-imprinted to bond the graphene layer 50 to the photoresist layer. In this embodiment, the graphene layer 50 is grown on the surface of a 6-inch circular copper foil 60 by using CVD (chemical vapor deposition), and the graphene layer 50 in this embodiment is in the form of a thin film. Specifically, the photoresist / micro-nano structure layer / organic layer composite structure C2 spin-coated with a fluorinated modified acrylic resin is covered on the surface of the graphene layer 50, and after covering, a nano-imprinter is used to perform imprinting for 120 seconds at a temperature of 120°C and a pressure of 20 bar, so that the graphene layer 50 is adhered to the fluorinated modified acrylic resin layer 40 and bonded.

[0082] like Fig. 9 As shown, the metal substrate 60 is peeled off to obtain an organic layer / micro-nano structure layer / photoresist layer / graphene layer composite structure C3.

[0083] like Fig.10As shown, the organic layer / micro-nano structure layer / photoresist layer / graphene layer composite structure C3 is covered on the surface of the substrate 70 so that the graphene layer 50 is attached to the substrate 70 and nano-imprinted, and the photoresist layer 40 is cured during the nano-imprinting process. The substrate 70 in this embodiment is an 8-inch circular silicon oxide layer 70, and the organic layer / micro-nano structure layer / photoresist layer / graphene layer composite structure C3 is covered on the first surface of the silicon oxide layer 70, and then a nano-imprinting machine is used to perform imprinting at a temperature of 60°C and a pressure of 20 bar for 60s, and ultraviolet light UV is used for 30s for curing. Under the action of UV, the fluorinated modified acrylic resin layer 40 is cured and a polycondensation reaction occurs. After the fluorinated modified acrylic resin layer 40 is cured, the surface energy becomes smaller, and the bonding between the graphene layer 50 and the fluorinated modified acrylic resin layer 40 is broken, and the graphene layer 50 will adhere to the surface of the silicon oxide layer 70.

[0084] like Fig.11 As shown, the organic layer / micro-nano structure layer / photoresist layer composite structure is peeled off to obtain the graphene layer 50 transferred to the substrate 70. It can be understood that since the surface energy of the fluorinated modified acrylic resin 40 after curing is very low, and the bonding force between the organic layer 10 / micro-nano structure layer 40 composite structure and the photoresist layer 40 (i.e., the fluorinated modified acrylic resin layer 40) is relatively large, the graphene layer 50 will remain on the surface of the silicon oxide layer 70 and will not be transferred away by the organic layer / micro-nano structure layer / photoresist layer composite structure during the peeling process.

[0085] like Fig.12 As shown, Raman spectroscopy is used to characterize the graphene layer 50 on the surface of the silicon oxide layer 70. It can be understood that the 2D peak is an important indicator for judging the quality of graphene, that is, a weak D peak and a strong 2D peak indicate that the graphene quality is high. If the D peak is strong, it means that the quality of the transferred graphene is poor. Fig.12 The above is the Raman spectrum curve of graphene obtained by the traditional transfer method. Fig.12 The following is a Raman spectrum curve of the graphene layer obtained by the transfer method proposed in the present invention. From the comparison of the Raman spectra, it can be seen that the D peak in the method proposed in the present invention is weaker and the 2D peak is stronger, and there are no other impurity peaks, indicating that the graphene transferred by the method proposed in the present invention is clean and of high quality.

[0086] Compared with the wet graphene transfer process, the graphene in the present application does not come into contact with water, thus preventing water molecules from adhering to the graphene surface and causing contamination. Furthermore, the present application can realize the transfer of large-area graphene films made by CVD.

[0087] It can be seen from the above technical solutions that the present invention has the following beneficial effects:

[0088] The present invention increases the contact area between the micro-nano structure layer and the photoresist layer through the micro-nano structure layer, thereby increasing the bonding force between the organic layer and the photoresist layer, realizing the transfer of a large-area graphene layer and ensuring the transfer quality;

[0089] By breaking the bond between the nanoimprint graphene layer and the photoresist layer, it is avoided that the photoresist layer remains on the surface after the graphene layer is transferred, and it is also avoided that the graphene layer is transferred away by the composite structure of the organic layer / micro-nano structure layer / photoresist layer during the stripping process;

[0090] The transferred graphene layer of the present invention is clean, complete and defect-free, thereby preventing the graphene layer from being contaminated by water molecules.

[0091] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0092] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A graphene transfer method based on nanoimprinting, characterized in that: The method comprises: Providing a substrate, the substrate comprising an organic layer and a micro-nano structure layer located above the organic layer, the micro-nano structure layer comprising spaced micro-nano units; Applying photoresist on the micro-nano structure layer to obtain a photoresist layer / micro-nano structure layer / organic layer composite structure; Covering the composite structure of photoresist / micro-nanostructure layer / organic layer on the graphene layer directly grown on the metal substrate and performing nanoimprinting to bond the graphene layer to the photoresist layer; The metal substrate is peeled off to obtain a composite structure of organic layer / micro-nano structure layer / photoresist layer / graphene layer; Covering the composite structure of organic layer / micro-nano structure layer / photoresist layer / graphene layer on the surface of the substrate so that the graphene layer and the substrate are bonded and nano-imprinting is performed, and curing the photoresist layer during the nano-imprinting process; The organic layer / micro-nano structure layer / photoresist layer composite structure is peeled off to obtain a graphene layer transferred to the substrate.

2. The graphene transfer method based on nanoimprinting according to claim 1, characterized in that: The preparation method of the micro-nano structure layer comprises: Spin-coating a nanoimprint glue on the surface of the organic layer, and allowing the nanoimprint glue to form a deposited glue layer on the surface of the organic layer; Providing a corresponding nanoimprint template, and aligning the nanoimprint template with the organic layer formed with the stacking glue layer for imprinting; After curing, the mold is demoulded to obtain a micro-nano structure layer on the surface of the organic layer.

3. The graphene transfer method based on nanoimprinting according to claim 1 or 2, characterized in that: The micro-nano units include columnar micro-nano units, and the columnar micro-nano units are distributed in an array; or, The micro-nano units include wire-grid-shaped micro-nano units, and the wire-grid-shaped micro-nano units are distributed at intervals along a first direction.

4. The graphene transfer method based on nanoimprinting according to claim 3, characterized in that: When the micro-nano unit is a columnar micro-nano unit, the height of the columnar micro-nano unit is greater than or equal to 1 μm, and the cross-sectional diameter of the columnar micro-nano unit is 500 nm to 1 μm; When the micro-nano unit is a wire-grid micro-nano unit, the height of the wire-grid micro-nano unit is greater than or equal to 1 μm, the width of the wire-grid micro-nano unit along the first direction is 500 nm to 1 μm, and the duty cycle of the wire-grid micro-nano unit is 50%.

5. The graphene transfer method based on nanoimprinting according to claim 1, characterized in that: The material of the photoresist layer is fluorinated modified acrylic resin.

6. The graphene transfer method based on nanoimprinting according to claim 1, characterized in that: The thickness of the photoresist layer between two adjacent micro-nano units is 2-3 μm; and / or, The ratio of the height of the micro-nano unit to the thickness of the photoresist layer between two adjacent micro-nano units is 1:2 to 1:

3.

7. The graphene transfer method based on nanoimprinting according to claim 1 or 2, characterized in that: The material of the organic layer is polycarbonate.

8. The graphene transfer method based on nanoimprinting according to claim 1, characterized in that: When the photoresist / micro-nanostructure layer / organic layer composite structure is covered on the graphene layer directly grown on the metal substrate and nano-imprinted, the nano-imprinting temperature is 90° C. to 150° C., the nano-imprinting pressure is 15 bar to 30 bar, and the nano-imprinting time is 120 s to 300 s.

9. The graphene transfer method based on nanoimprinting according to claim 1, characterized in that: When the organic layer / micro-nano structure layer / photoresist layer / graphene layer composite structure is covered on the surface of the substrate to make the graphene layer adhere to the substrate and perform nanoimprinting, the temperature of nanoimprinting is 90° C. to 150° C., the pressure of nanoimprinting is 15 bar to 30 bar, the time of nanoimprinting is 60 s to 300 s, and the photoresist layer is ultraviolet-cured for at least 30 s during the nanoimprinting process.

10. The graphene transfer method based on nanoimprinting according to claim 1, characterized in that: The material of the substrate is one of silicon and silicon oxide; and / or, The metal substrate includes copper foil.

Images