Manufacturing of 2d-material coated objects

Abstract

The present invention relates to a method for manufacturing an object comprising at least one surface wherein at least part of said surface is adhered to at least one 2D-material layer, said method comprising the successive steps of (a) providing a multilayer assembly comprising at least one metallic layer (layer L1), wherein the layer L1 has a predetermined average thickness (average thickness T1); at least one 2D-material layer; and optionally at least one polymer layer (layer 12), (b) reducing the average thickness T1 to an average thickness T2, (c) applying at least one adhesive layer onto at least part of the multilayer assembly, (d) etching away the layer L1 having the average thickness T2 of the multilayer assembly as obtained in step (c), and (e) transferring at least part of the 2D-material layer onto at least part of a surface of an object.

Description

[0001]Manufacturing of 2D-material coated objects Field of the invention The present invention relates to an improved method for the manufacturing of 2D-material coated objects, in particular graphene coated objects. Background of the invention Graphene is an allotropic form of carbon that consists of a two- dimensional hexagonal arrangement of sp2-bonded carbon atoms. Each layer of graphene is essentially a one-atom-thick planar layer of carbon atoms that are bonded in a honeycomb crystal lattice. Graphene can be in forms having one, two, hundreds or thousands of graphene layers. Graphene has attracted much attention due to its properties, such as high electronic mobility, thermal conductivity, great strength, flexibility and transparency. These properties make graphene an ideal candidate in many applications, such as electronics, touch screen applications and sensors. Among the different ways of manufacturing graphene, a Chemical Vapor Deposition (CVD) process on metallic layers has become the method of choice for the low-cost manufacturing of large areas of graphene layers. In this process, a metallic foil such as nickel, copper, iridium, and platinum foils, acts as a catalyst for the growth of a graphene film on its surface. The method mainly involves the adsorption, decomposition and segregation of a carbon-containing precursor on a metal surface at an elevated temperature either at low or atmospheric pressure. For many applications, graphene layers manufactured by CVD must be transferred to a target object such as for example silicon wafers, glass plates, polymeric films, and lenses. Since graphene is a very thin material, handling and transferring without damaging is extremely challenging. Different approaches have been developed for transferring CVD graphene. In wet transfer methods, such as disclosed in ACS Nano 2011, 5, 9, 6916-6924 (DOI: 10.1021 / nn201207c), an aqueous etchant solution is used to dissolve the metal foil on which CVD graphene has been grown. This results in a graphene layer floating onto the surface of the etching solution. The graphene layer is successively fished out of the solution by the target object. This approach has the disadvantage that graphene layers obtained after transferring are contaminated by residues from the etching solution. Furthermore, this method does not enable a precise positioning of the graphene coating on the target object. In recent years, dry transfer methods have been developed. Compared to wet transfer, dry transfer methods have different advantages such as lower cost, improved positioning of the graphene coating on the target object and less contamination. CN107230615 discloses a method for preparing and transferring a patterned graphene electrode for the manufacturing of a transistor. First, a graphene layer is grown on a copper foil by CVD. The grown graphene layer is transferred to a flat substrate after which it is treated with ultraviolet and ozone, doped and patterned. Transferring is performed by spin-coating a PMMA layer on the graphene-grown copper foil, cut the foil into small pieces and stick the foil to an adhesive tape. The tape is successively immersed into an FeCl3 / HCl solution to corrode the copper foil after which it is washed several times with water and a diluted H2O2solution. The tape is then attached to the flat substrate after which the substrate is heated and dried. The tape is removed and the substrate is soaked in acetone and acetic acid successively to remove the PMMA layer. Finally, the substrate is annealed at 350°C for 30 minutes under an H2 / Ar atmosphere. Nano Lett.2015, 15, 3236-3240 (DOI: 10.1021 / acs.nanolett.5b0 0440) discloses a cost-effective, and easily scalable method of transferring and patterning large-area graphene using pressure sensitive adhesive films (PSAFs) at room temperature. First, a large-area graphene film is synthesized by CVD on a high purity copper foil. After laminating PSAF on the as-grown graphene on the copper foil, the graphene on the other side of the foil is removed by spray etching with 0.1 M ammonium persulfate (APS) solution. After completely removing Cu by further etching, the graphene on the PSAF is rinsed with water and transferred onto target substrates. Finally, the supporting PSAF is pealed-off. One of the major drawbacks of the known prior art dry transfer methods is that after transferring, the graphene layers have a high level of structural and morphological defects such as cracks and ripples and that the graphene layers do not uniformly adhere to the target substrate. In view of the above, there is thus a need for an improved method for the manufacturing of graphene coated objects, in particular a method enabling the manufacturing of objects coated with a uniformly adhered graphene layer in which the graphene layer has a low level of structural and morphological defects. Summary of the invention The inventors have now surprisingly found that it is possible to provide an improved method fulfilling the above mentioned needs and does not have the drawbacks as discussed above. It is thus an object of the present invention to provide a method for manufacturing an object comprising at least one surface wherein at least part of said surface is adhered to at least one 2D-material layer, wherein the 2D-material is graphene or hexagonal boron nitride, said method comprising the successive steps of: (a) providing a multilayer assembly having a front face and a back face comprising, from back to front: o at least one metallic layer (layer L1, herein after) wherein the layer L1 has a predetermined average thickness (average thickness T1, herein after), o at least one 2D-material layer, and o optionally at least one polymer layer (layer L2, herein after), (b) reducing the average thickness T1 to an average thickness T2 by subjecting the layer L1 to an etching step, wherein the average thickness T2 is ranging from 5.0 % to 95.0 % of the average thickness of T1, (c) applying at least one adhesive layer onto at least part of the front face of the multilayer assembly, (d) etching away the layer L1 having the average thickness T2 of the multilayer assembly as obtained in step (c), and (e) transferring at least part of the 2D-material layer onto at least part of a surface of an object. It is a further object of the present invention to provide an object comprising at least one surface wherein at least part of said surface is adhered to at least one 2D-material layer as obtained by the method of the invention. Detailed description of the invention The term “comprising”, as used in the claims, should not be interpreted as being limited to the means mentioned thereafter; such a term does not exclude other elements or steps. The term should be read as specifying the presence of the stated features, integers, steps, or components, without, however, precluding the presence or addition of one or more other features, integers, steps or components, or groups thereof. Thus, the scope of the expression “a method comprising steps A and B” should not be limited to the method consisting only of steps A and B. This means that, with respect to the present invention, the only relevant steps of the method are A and B. Accordingly, the terms “comprising” and “including” encompass the more limiting terms “consisting mainly of” and “consisting of “. Within the scope of the present invention, the term “optional(ly)” means that an event or circumstance as described may or may not occur, and that the description comprises cases in which that event or circumstance occurs and cases in which it does not. It was surprisingly found that the method of the present invention enables to obtain 2D-material coated objects having a 2D-material layer which has a high crystallinity, a low level of structural and morphological defects such as cracks and ripples, and has a low level of impurities and residues. Furthermore, it was surprisingly found that the 2D-material coated objects obtained by this method have a 2D-material layer which adheres uniformly to the surface of the object. Within the context of the present invention, the expression “at least one metallic layer (layer L1, herein after)” is intended to denote one or more than one layer (L1). It is understood that the same applies for the expressions “at least one polymer layer (layer L2, herein after)” and “at least one 2D-material layer”. In the rest of the text, the terms “metallic layer (layer L1, herein after)”, “polymer layer (layer L2, herein after)”, “2D-material layer” are understood, for the purposes of the present invention, both in the plural and the singular form. As said, in step (a) of the method according to the present invention a multilayer assembly having a front face and a back face is provided in which the layer L1 has a predetermined average thickness T1. Within the context of the present invention, the term “average thickness” of a layer is determined by dividing the volume of said layer by the surface area of the front face of the layer. According to a preferred embodiment in step (a) of the method of the present invention, the average thickness T1 of the layer L1 is of at most 110.0 µm, preferably at most 90.0 µm, preferably at most 60.0 µm, preferably at most 40.0 µm and more preferably at most 30.0 µm. Advantageously, the average thickness T1 of the layer L1 is at least 4.0 µm, preferably at least 8.0 µm, preferably at least 10.0 µm, preferably at least 15.0 µm and more preferably at least 20.0 µm. According to a preferred embodiment in step (a) of the method according to the present invention, the average thickness T1 of the layer L1 is ranging from 4.0 µm to 110.0 µm, preferably from 8.0 µm to 90.0 µm, preferably from 10.0 µm to 60.0 µm, preferably from 15.0 µm to 40.0 µm, and more preferably from 20.0 to 30.0 µm. The layer (L1) of the multilayer assembly can be made from one or more than one metal. Preferably, the metal is selected from the group of transition metals, and more preferably from the group 7 to 12. Non-limiting examples of such transition metals from the group 7 to 12 are Copper (Cu), Nickel (Ni), Ruthenium (Ru), Iridium (Ir), Platinum (Pt), Cobalt (Co), Palladium (Pd), Rhenium (Re), Gold (Au), and Silver (Ag). Preferably, the metal is Cu or Ni, more preferably, the metal is Cu. In general, the layer (L1) can be in the form of a single crystal layer or in the form of a polycrystalline layer. Within the scope of the present invention, the expression “2D- material” as used herein, may have the broadest meaning generally understood in the art and may refer to a crystalline material consisting of one single layer of homo-atoms or hetero-atoms and wherein the crystalline unit cells are repeated in two spatial dimensions but not in the third dimension, the 2D-material being graphene or hexagonal boron nitride, even more preferably the 2D-material is graphene. As said, in step (a) of the method according to the present invention, the multilayer assembly having a front face and a back face can optionally comprise at least one polymer layer (layer L2, herein after). When present, the layer L2 of the multilayer assembly can be made from one or more than one polymer. The main purpose of layer L2 is notably to act as a protective support layer for the 2D-material during the different method steps. Therefore, the choice of the polymer is in general determined by its film-formation properties, wetting and adhesion on the 2D-material, mechanical strength and flexibility. In general, the polymer may be selected from organic and inorganic polymers having a typical average molecular weight between 1000 and 500000 g / mol. Non limiting examples of polymers suitable to use in the multilayer assembly, as detailed above, are poly(meth)acrylates, polycyanoacrylate, cellulose and cellulose derivatives, polycarbonates, polyesters, polyurethanes, epoxy resins, silicones, polyvinyl butyrals and poly(meth)acrylamides. Preferably, the polymer of the layer L2 of the multilayer assembly is selected from the group consisting of poly (methyl methacrylate) (PMMA), polydimethylsiloxane (PDMS) and polycyanoacrylate, more preferably, the polymer is poly (methyl methacrylate) (PMMA). The multilayer assembly, as provided in step (a) of the method according to the present invention, can be prepared by a variety of methods known in the art. According to one embodiment of the present invention, the multilayer assembly, as detailed above, can be prepared by a method comprising the steps of: 1. providing the layer (L1), as detailed above, having the average thickness T1, as detailed above, 2. applying the at least one 2D-material layer, as detailed above, to at least one side of said layer (L1), and 3. optionally, applying the layer (L2), as detailed above, to the at least one 2D-material layer, as detailed above. The layer (L1), as detailed above, having the average thickness T1, as detailed above, may be commercially available such as polycrystalline metal foils and single crystal metal substrates, or may be prepared by using methods known to the skilled in the art. Non limiting examples of commercially available polycrystalline metal foils are polycrystalline Cu and polycrystalline Ni foils, in particular commercially available polycrystalline Cu and Ni foils with a purity of more than 99% are used, or a purity of more than 99.5%, or more than 99.9%, and most preferably more than 99.99%. Non limiting examples of commercially available single crystal metal substrates are single crystal substrates such as Cu(111), Cu(100), Cu (001) and the like. Preferably, single crystal metal substrates are polished single crystal plates and single crystal metal foils. Recently, novel methods such as disclosed in Science, vol 362, pp. 1021-1025 have been developed for the manufacturing of high purity single crystal metal foils such as single crystal Cu and Ni foils by the transformation of the economical polycrystalline metal foils into single crystal foils. Commercially available polycrystalline metal foils, single crystal metal plates and foils may come with a thin native oxide layer. Such layers are preferably removed prior to use by conventional methods known to the skilled in the art. For example for Cu and Ni substrates, immersion in acetic acid is well known in the art. The at least one 2D-material layer, as detailed above, can be applied to at least one side of said layer (L1), as detailed above, by using known techniques such as notably chemical vapor deposition (CVD), molecular beam epitaxy (MBE), Magnetron Sputtering or Laser Irradiation, preferably by chemical vapor deposition (CVD). It is further understood that the skilled person in the art will carry out said chemical vapor deposition (CVD) according to general practice such as notably applying a gas precursor to a growth substrate (which may act as a catalyst) in the presence of an activation or power source. In the CVD process, different parameters can be optimized, such as pressure, temperature, precursor nature, gas flow state, wall / substrate temperature, depositing time, and activation manner. Methods for the manufacturing of 2D-materials by CVD of 2D-materials are for example disclosed in iScience, 2022, 25, pp. 103832- 103863 and Chem. Rev 2018, 118, pp.6091-6133 and the references therein, the whole content of said references being herein incorporated by reference. Methods for the CVD of graphene are notably disclosed in Molecules, 2020, 25, pp. 3856-3917 and Acc. Chem. Res., 2013, 46, pp. 2329-2339 and the references therein. Methods for the CVD of h-BN are notably disclosed in Acc. Mater. Res.2022, 3, pp.748-760 and references therein, the whole content of said references being herein incorporated by reference. Optionally, in step 3. of the method for manufacturing the multilayer assembly, the layer (L2), as detailed above, can be applied to the at least one 2D-material layer, as detailed above, by using known processing techniques in the art, those including notably conventional coating and printing techniques such as dip coating, knife coating, extrusion coating, spin coating, spray coating, slide hopper coating, curtain coating, valve jetting, offset printing, flexo printing, pad printing and inkjet printing. Preferably, the layer (L2) in the multilayer assembly, as provided in step (a) of the method according to the present invention, is prepared by using the spin coating technique thereby using a polymer solution or dispersion in which the polymer, as detailed above, in particular PMMA, is dissolved or dispersed in at least one solvent such as acetone, ethyl acetate, ethyl methyl ketone and the like. For example; PMMA solutions in acetone with a concentration ranging between 1.0 wt% and 10.0 wt%, preferably between 2.0 wt% and 5.0 wt% can notably be used for the manufacturing of a PMMA layer which is applied to the at least one 2D-material layer, as detailed above. It is further understood that the skilled person in the art will carry out said spin coating technique according to general practice such as notably applying optimal solution or dispersion concentration, solution viscosity, solution surface tension, dispense volume, turning speed and turning time. For example, spin-coating can be performed at a turning speed ranging between 1000 and 5000 rounds per minute (rpm) and for a duration ranging between 1 and 3 minutes. As mentioned, according to step (b) of the method according to the present invention, the average layer thickness T1 of the metallic layer L1 is reduced to an average layer thickness T2 by subjecting layer L1 to an etching step, wherein the average thickness T2 is ranging from 5.0 % to 95.0 % of the average thickness of T1. As exemplified here under, it was surprisingly found by the inventors that only when the average thickness T1 was reduced to average thickness T2 in step (b) ranging from 5.0 % to 95.0 % of the average thickness of T1, the method of present invention results in the manufacturing of 2D- materials uniformly adhered to said object, without many major cracks, without many residues and without folds. Advantageously, in step (b) of the method according to the present invention, the average thickness T1 of the layer L1 is reduced to an average layer thickness T2 of at least 10.0 % of the average thickness of T1, preferably at least 20.0 % of the average thickness of T1, more preferably at least 30.0 % of the average thickness of T1, more preferably at least 40.0 % of the average thickness of T1, most preferably at least 50.0 % of the average thickness of T1. It is further understood that in step (b) of the method according to present invention, the average layer thickness T1 of the layer L1 is advantageously reduced to an average layer thickness T2 of at most 90.0 % of the average thickness of T1, preferably at most 80.0 % of the average thickness of T1, more preferably at most 70.0 % of the average thickness of T1, most preferably at most 65.0% of the average thickness of T1. In a preferred embodiment of step (b) of the method according to the present invention, the average thickness T1 of the layer L1 is reduced to an average thickness T2 which is from 10.0 % to 90.0 % of the average thickness of T1, more preferably from 20.0 % to 80.0 % of the average thickness of T1, more preferably from 40.0 % to 70.0 % of the average thickness of T1, most preferably from 50.0 % to 65.0 % of the average thickness of T1. According to certain embodiments of step (b) of the method according to the present invention, with the proviso that the average thickness T2 is smaller than average thickness T1, the average thickness T2 of the layer L2 is ranging from 1.0 µm to 24.0 µm, preferably from 4.0 µm to 20.0 µm, more preferably from 7.0 µm to 15.0 µm, most preferably from 8.0 µm to 12.0 µm. According to certain embodiments of step (b) of the method according to the present invention, with the proviso that the average thickness T2 is smaller than average thickness T1, the average thickness T2 of the layer L1 is at least 1.0 µm, preferably at least 4.0 µm, more preferably at least 7.0 µm, most preferably at least 8.0 µm. According to certain embodiments of step (b) of the method according to the present invention, with the proviso that the average thickness T2 is smaller than average thickness T1, the average thickness T2 of the layer L1 is at most 24.0 µm, preferably at most 20.0 µm, more preferably at most 15.0 µm, most preferably at most 12.0 µm. As mentioned, in step (b) of the method according to the present invention, the layer L1 is subjected to an etching step (etching step (b)). This etching step (b) can be carried out by using standard etching techniques such as listed in CRC Handbook of Metal Etchants 1st Edition, P. Walker and W. H. Tarn, 1991, pp.9 - 69, the whole content of said reference being herein incorporated by reference.These standard etching techniques include wet chemical etching techniques, electro etching, plasma etching, and vapor etching. Vapor etching can for example be performed with volatile acids such as hydrofluoric acid (HF) and hydrochloric acid (HCl). Wet chemical etching techniques are particularly preferred thereby bringing the layer L1, as detailed above, of the multilayer assembly in contact with at least one etching solution. This can for example be performed by dipping said multilayer assembly into at least one etching solution, by exposing said layer L1 to a continuous flow, stream or spray of at least one etching solution, or by placing said multilayer assembly onto at least one etching solution. In general, in the latter technique, the surface tension of the etching solution allows the multilayer assembly to float onto the etching solution. This technique advantageously enables to contact said etching solution selectively to said layer L1. It is understood that the skilled person in the art will carry out said wet etching step according to general practice such as notably using optimal etching solution composition, temperature and time. Within the context of the present invention, the expression at least one etching solution is intended to denote one or more than one etching solution. In the rest of the text, the term “etching solution” is understood, for the purposes of the present invention, both in the plural and the singular form. Within the context of the present invention, the term “etching solution” is intended to refer to a solution capable of selectively etching and removing metal layers. As used herein, the etching solution can be aqueous or non- aqueous. Non-limiting examples of non-aqueous etching solutions are Lewis acids in non-aqueous electrolytes. Standard aqueous etching solutions can be alkaline, neutral or acidic. Etching solutions might comprise strong acids, strong bases, strong oxidizing agents, organic solvents and buffering agents. Etching solutions might further comprise one or more additives such as complexing agents, surfactants, salts, electrolytes, defoaming agents, viscosity control agents such as glycerin, and wetting agents. Gases may be bubbled through a solution such as chlorine as etching agent or nitrogen for a stirring action. Non-limiting examples of optimal aqueous etching solutions notably include solutions containing ammonium persulfate ((NH4)2S2O8), hydrofluoric acid (HF), Iron(III) nitrate Fe(NO3)3, iron(III) chloride (FeCl3), Copper(II) chloride (CuCl2), hydrogen peroxide (H2O2), copper(II) sulfate (CuSO4), hydrochloric acid (HCl), hydrobromic acid (HBr), nitric acid (HNO3), sulfuric acid (H2SO4), sodium hydroxide (NaOH), phosphoric acid (H3PO4) and combinations thereof. Preferably, the etching solution, as used in step (b) of the method according to the present invention, is an aqueous ammonium persulfate solution with a concentration between 0.01 M and 1.00 M, preferably between 0.05 M and 0.50 M, more preferably between 0.075 M and 0.200 M. Generally the wet chemical etching, as detailed above, may be carried out while stirring the etching solution, as detailed above. Stirring can be performed by rotational stirring, magnetic stirring and bubble stirring. Furthermore, wet chemical etching may be carried out in the presence of an energy source to accelerate etching process. Examples of energy sources are heat, ultrasound and microwave. The wet chemical etching, as detailed above, is preferably carried out in the presence of ultrasound. Ultrasound may accelerate surface treatment processes. The wet chemical etching, as detailed above, can be carried out using sonication baths, such as traditional ultrasonic cleaners. In the context of the present invention, it is understood that the etching step (b) needs to be carried out in such a time period that the average thickness T1 of the layer L1, as detailed above, can be reduced to the average thickness T2, as detailed above. Advantageously, the time period of the etching step (b) may range between 2 and 50 minutes, preferably between 10 and 45 minutes, more preferably between 20 and 40 minutes, most preferably between 25 and 35 minutes. According to one embodiment of the present invention, the multilayer assembly as obtained in step (b) is further dried in order to remove the excess of said etching solution prior to step (c). It is understood that the skilled person in the art will carry out said drying according to general practice such as notably using dry blowing, air knife drying and the use of absorbing substrates. As mentioned, according to step (c) of the method according to the present invention, at least one adhesive layer is applied onto at least part of the front face of the multilayer assembly as obtained in step (b). It is understood that the skilled person in the art will carry out said application of said adhesive layer according to conventional application techniques. Non-limiting examples of suitable application techniques are manual gentle pressure, pressure sensitive labeling, stamping, hot stamping, lamination, coating and printing techniques, and the like. Non-limiting examples of suitable pressure sensitive labeling technique mention may be made of pressure labeling techniques performed in a discreet sheet process, a manual process or a continuous roll-to-roll process. Non-limiting examples of suitable coating and printing techniques mention may be made of dip coating, knife coating, extrusion coating, spin coating, spray coating, slide hopper coating, curtain coating, valve jetting, offset printing, flexo printing, pad printing and inkjet printing. Preferably, the at least one adhesive layer is applied onto at least part of the front face of the multilayer assembly as obtained in step (b), as detailed above, by applying manual gentle pressure on the front face of the at least one adhesive layer. Within the context of the present invention, the expression “manual gentle pressure” is intended to denote the act of applying a pressure of 100 to 500g, which corresponds to applying a pressure of 1 to 5 Pa. It is understood that the skilled person in the art will carry out said manual gentle pressure technique according to general practice, that is to say notably, under optimal environment and temperature conditions. Preferably, the at least one adhesive layer is applied onto at least part of the front face of the multilayer assembly as obtained in step (b), as detailed above, by applying manual gentle pressure on the front face of the at least one adhesive layer, as detailed above, at room temperature. According to one embodiment in step (c) of the method of the present invention, the adhesive layer comprises one or more adhesive materials. It is further understood that the adhesive material can be any organic or inorganic adhesive material that can suitably adhere to the front face of the multilayer assembly as obtained in step (b). Non-limiting examples of suitable adhesive materials mention may be made of acrylic based adhesives, silicon based adhesives, rubber- based adhesives such as butadiene-styrene, butyl, polyisobutylene or nitrile compounds, latex-based adhesives, epoxy adhesives, polyurethane adhesives, polyimide adhesives, and cyanoacrylates. Preferably, the adhesive layer comprises one or more adhesive materials selected from the group consisting of acrylic based adhesives, silicon based adhesives, epoxy adhesives, polyurethane adhesives, polyimide adhesives, and cyanoacrylates, more preferably the adhesive layer comprises an acrylic based adhesive. According to one embodiment of the method of the present invention, the adhesive layer is an adhesive tape, wherein said adhesive tape comprises one or more adhesive material, as detailed above, said adhesive material being applied onto at least one substrate carrier. Non-limiting examples of suitable substrate carriers may be made of polyvinylchloride (PVC) foils, polyethylene terephthalate (PET) foils such as Mylar®(also known as Biaxially-oriented polyethylene terephthalate - BoPET), polyethylene naphthalate (PEN) foils, polycarbonate (PC) foils, polyimide foils such as Kapton®, polyethylene foils, polypropylene foils, polyamides foils such as nylon, Polytetrafluoroethylene (PTFE) foils such as Teflon, woven cloth, paper, aluminum and copper foils. Preferably, the adhesive layer is an adhesive tape comprising one or more adhesive materials, as detailed above, preferably the adhesive material is an acrylic based adhesive, wherein said adhesive materials are applied onto at least one substrate carrier selected from polyvinylchloride (PVC) foils or polyethylene terephthalate (PET) foils such as Mylar® (also known as Biaxially-oriented polyethylene terephthalate - BoPET). More preferably, the adhesive layer is an adhesive tape comprising one or more adhesive materials, as detailed above, wherein said adhesive materials are applied onto at least one substrate carrier being a polyvinylchloride (PVC) foils. When the adhesive layer, as detailed above, is applied, said adhesive layer may be applied onto the whole front face of the multilayer assembly, as obtained in step (b) and may even be larger than the multilayer assembly as obtained in step (b), thereby allowing an easier handling during all successive steps by holding the multilayer assembly via said adhesive layer. The adhesive layer, as detailed above, may be synthetically prepared by a variety of methods known in the art, or may be commercially available. Non limiting examples of commercially available adhesive layer suitable for use in the method of the present invention include Blue transparent PVC surface protection tape from Micro to Nano, which consists of an acrylic based adhesive as adhesive material, said adhesive material is applied onto a PVC film substrate carrier. Optionally, if desired, the back face of the multilayer assembly as obtained in step (c), as detailed above, may be subjected to at least one cleaning step prior to step (d) of the present invention, as detailed above, such as a rinsing or a wiping step. Said cleaning step, as detailed above, has the advantage to remove the at least one 2D-material layer, as detailed above, from the back face of the multilayer assembly, which may be present after step (a) of providing a multilayer assembly, as detailed above. Thus, said cleaning step, enables to reduce the level of residues. As mentioned, according to step (d) of the method according to the present invention, the layer L1 having the average thickness T2 of the multilayer assembly as obtained in step (c), as detailed above, is etched away (etching away step (d)). The etching away step (d) can be carried out by using standard etching techniques such as listed in CRC Handbook of Metal Etchants 1st Edition, P. Walker and W. H. Tarn, 1991, pp.9 - 69, the whole content of this reference being incorporated by reference.These standard etching techniques include wet chemical etching techniques, electro etching, plasma etching, and vapor etching. Vapor etching can for example be performed with volatile acids such as notably hydrofluoric acid (HF), or hydrochloric acid (HCl). Wet chemical etching techniques are particularly preferred thereby bringing the layer L1 having the average thickness T2, as detailed above, of the multilayer assembly in contact with at least one etching solution. This can for example be performed by dipping said multilayer assembly into at least one etching solution, by exposing said layer L1 having an average thickness T2 to a continuous flow, stream or spray of at least one etching solution, or by placing said multilayer assembly onto at least one etching solution. In general, in the latter technique, the surface tension of the etching solution allows the multilayer assembly to float onto the etching solution. This technique advantageously enables to contact said etching solution selectively to said layer L1 having the average thickness T2. It is understood that the skilled person in the art will carry out said wet etching step according to general practice such as notably using optimal etching solution composition, temperature and time. All features detailed above for the etching solution and the wet chemical etching, as detailed above in etching step (b) of the method of the present invention, can be provided for the etching away of the layer L1 having the average thickness T2 of the multilayer assembly, as detailed above in step (d) of the method of the present invention. In the context of the present invention, it is understood that the etching away step (d) need to be carried out in such a time period that the layer L1 having the average thickness T2 is substantially removed from the multilayer assembly obtained in step (d). Within the context of the present invention, the expression “substantially removed”, is intended to denote that the metal of the layer (L1), as detailed above, is present in trace amounts on the 2D-material layer after step (d), being understood that these trace amounts of said metal do not substantially modify the properties, in particular the properties of the 2D- material layer, after step (d). In particular, within the context of the present invention, the term “trace amounts” is intended to denote that the metal of the layer (L1), as detailed above, could not be seen visually anymore. Advantageously, the time period of the etching away step (d) may range between 1 and 24 hours, or between 4 and 20 hours, or between 8 and 16 hours, or between 10 and 12 hours. Optionally, if desired, the etching away step (d) of the method of the present invention, as detailed above, may be followed by at least one cleaning step prior to step (e) of the present invention, as detailed above, such as a spraying step with deionized water. Optionally, if desired, the etching away step (d) of the method of the present invention, as detailed above, may be followed by at least one drying step prior to step (e) of the present invention, such as by dry blowing or by an air knife. According to certain embodiments of the method of the present invention, the etching away step (d) of the method of the present invention, as detailed above, may be followed by at least one cleaning step, preferably a spraying step with deionized water, subsequently followed by a drying step, preferably a dry blowing step, prior to step (e). Said at least one drying step and / or cleaning step, as detailed above is advantageous in that the impurities and residues which may be present on the back face of the 2D-material layer may be removed, thereby enabling an improved step (e), as detailed above. As said, according to step (e) of the method according to the present invention, at least part of the 2D-material, as detailed above, is transferred onto at least part of a surface of an object (transfer step (e)). Within the context of the present invention, the expressions “at least part of the 2D-material” is intended to denote that a predetermined part of the 2D-material, or the whole 2D-material may be transferred. Within the context of the present invention, the expression “at least part of a surface of an object”, is intended to denote that a predetermined part of the surface of an object, or the whole surface of an object may be used. One advantage of the method of the present invention is that the transfer step (e), as detailed above, can be carried out on a variety of objects, without deteriorating, structurally or morphologically, the 2D-material layer, as detailed above. More in particular, the transfer step (e) allows to transfer the 2D-material layer, without the formation of cracks or ripples on said 2D- material layer when transferred onto at least part of a surface or an object. Thus, the method according to the present invention enables the transfer of the 2D-material layer, as detailed above, on the surface of a variety of objects, said objects may consequently have complex shapes and geometries. It is understood that the choice of the object may be dependent on the end-use of said object, preferably the object is a shaped article. It is understood that the shaped article may be of any shape, such as for example, round shapes, flat-shapes, wire-shapes, or complex 3D shapes with or without cavities, or a combination thereof. Preferably, the shaped article has a flat-shape, such as a wafer. Within the context of the present invention, the object, as detailed above, may be made from any material suitable for the desired use. Non-limiting examples of suitable object material may be made of polymers, such as polyimide (such as Kapton®), poly(ethylene terephthalate) (PET), polyether ether ketone (PEEK) or polyurethane (PUR); metals; aluminium oxide; ceramics; or non-metals such as silicon or glass (SiO2). Preferably, the object is selected from the group consisting of silicon wafers, polyimide (such as Kapton®), polyethylene terephthalate (PET), or glass, more preferably, the object is a silicon wafer. Optionally, if desired, the object, as detailed above, may be subjected to at least one pre-treatment step prior to the transfer of the at least part of the 2D-material layer as detailed above, such as a cleaning step, an etching step and the like. According to the present invention, the transfer step (e), as detailed above, may be carried out by any known transfer techniques, such as by dry transfer, mechanical exfoliation, or combination thereof. Preferably, the transfer step (e), as detailed above, is carried out by dry transfer. In general, said dry transfer method is carried out by applying the back face of a 2D-material layer onto the surface of an object, such as for example by applying manual gentle pressure, pressure sensitive labeling, stamping, hot stamping, lamination, coating and printing techniques, and the like. Preferably, the transfer step (e), as detailed above, is carried out by dry transfer by applying manual gentle pressure on the front side of the adhesive layer, as detailed above. It is understood that the definition of “manual gentle pressure”, as detailed above, equally applies for this embodiment. It is understood that the skilled person in the art will carry out said manual gentle pressure according to general practice, that is to say notably, under optimal environment and temperature conditions. Preferably, the transfer step (e), as detailed above, is carried out by dry transfer by applying manual gentle pressure on the front side of the adhesive layer at room temperature. In general, the resulting object obtained after the transfer step (e), as detailed above, is then subsequently immersed in a solvent. In general, said solvent is chosen in such a way that any layers which may have been applied on the front face of the 2D-material layer are detached (i.e. delaminated) from said front face, and / or at least partially dissolved, without altering the at least one 2D-material layer, or the object, as detailed above. Preferably, the transfer step (e) is carried out by applying the back face of the at least one 2D-material layer, as obtained in step (d), onto at least part of a surface of an object, as detailed above, subsequently followed by a step of immersion said object in a solvent. More preferably, the transfer step (e) is carried out by applying the back face of the at least one 2D-material layer, as obtained in step (d), onto at least part of a surface of an object by dry transfer, preferably by applying manual gentle pressure on the front side of the adhesive layer, as detailed above, more preferably, at room temperature, subsequently followed by a step of immersion of said object in a solvent. In particular, the immersion of said resulting object obtained after the transfer step (e), as detailed above, advantageously allows the delamination of the adhesive layer from said resulting object, without deteriorating the later or the 2D-material layer, as detailed above. Further, when the front face of the at least one 2D-material layer, as obtained in step (d), is adhered to the at least one polymer layer L2, as detailed above, the immersion step of said object advantageously enables the polymer layer L2, as detailed above, to dissolve and / or to delaminate from the front of the 2D-material layer, as detailed above. Non-limiting examples of such solvents suitable for use in a step of immersion as detailed above, mention may be made of organic solvents, such as ethyl acetate, methyl ethyl ketone, acetone or combination thereof. Preferably, the solvent is selected from the group consisting of ethyl acetate, methyl ethyl ketone and acetone, more preferably, the solvent is acetone. Advantageously, the time period of said step of immersion of transfer step (e) of the method of the present invention, as detailed above, may range between 1 and 24 hours, or between 2 and 12 hours, or between 3 and 8 hours, or between 4 and 6 hours. Optionally, if desired, the transfer step (e), as detailed above, is followed by at least one cleaning step, such as a rinsing step with a solvent. Optionally, if desired, the transfer step (e), as detailed above, is followed by at least one drying step, such as by dry blowing or by an air knife. According to certain embodiments of the method of the present invention, the transfer step (e), as detailed above, is followed by at least one rinsing step with a solvent, subsequently followed by at least one drying step, such as by dry blowing or by an air knife. Another aspect of the present invention is an object comprising at least one surface wherein at least part of said surface is adhered to at least one 2D-material layer as obtained by the method of the invention. It is understood that all definitions and preferences, as described above, equally apply for all further embodiments, as described below. Examples The invention will now be described in more details with reference to the following examples, whose purpose is merely illustrative and not intended to limit the scope of the invention. Raw materials ^ Polycrystalline copper foils (99.99% purity, 25 ^m thickness) were purchased from MTI corporation (USA). ^ Adhesive tape: Blue transparent PVC surface protection tape with an acrylic adhesive layer was purchased from Micro to Nano (Netherlands)). ^ Ammonium Persulfate purchased from VWR chemicals. ^ PMMA purchased from Micro Chem. ^ Silicon on insulator (SOI) wafer such as SiO2-based SOI wafers purchased from Si-Mat. General procedures Preparation of the multilayer assembly (as provided in step (a) of the method according to the present invention): Before use, Cu foils were cleaned with acetone in an ultrasonic bath for 15 min, then in isopropanol for 15 min, and finally blown dry with nitrogen. The native copper oxide layer was removed by etching in acetic acid (99.5% purity) at room temperature for 10 min, followed by rinsing in deionized water, isopropanol (IPA) and acetone and dried with a nitrogen flow. Graphene was subsequently grown on the copper foil in a quartz reactor according to the following procedure. The copper foil was heated slowly at a temperature up to 1000 °C under a H2 (200 sccm, 99.999% purity) environment. When the substrate temperature reached 1000 °C, the temperature was maintained for 15 min. Mono- or double-layer graphene was then grown by admitting 0.5 sccm of CH4 (99.99% purity) for 3 h following the procedure as disclosed in Pham et al., Materials Chemistry and Physics 224, 286-292 (2019), incorporated herein by reference, at a pressure of around 10 Pa. The sample was then cooled rapidly (100 °C / min) between 1000 °C and 700 °C, then slowly (50 °C / min) between 700 °C and room temperature (RT). The whole process of growing graphene was carried out under constant flow of 200 sccm H2. In this process of growing graphene, said graphene was deposited onto both sides of the Cu foil, however, the graphene coating grown on the front face of the copper foil has a higher crystallinity than the graphene coating grown on the back face of the foil. In all experiments, only the graphene coating grown on the front face of the copper foil was transferred to an object. For the examples in which the multilayer assembly contained a polymer layer, a PMMA layer was spin coated on the front face of the Cu foil. Spin-coating was performed at 3000 round per minute (rpm) during 2 minutes using a 3 wt% PMMA solution. Partial etching (according to step (b) of the method according to the present invention): The multilayer assembly comprising the Cu foil, the CVD-grown graphene layer and optionally the PMMA layer was placed onto an aqueous 0.1 M Ammonium Persulfate (APS) solution, backside down, to partially etch the backside of the Cu foil, for a period of 30 min, at room temperature. The etching time was varied (see examples hereunder for details). The partially etched sample was picked up from the solution and deposited on an absorbing sheet of paper to remove the excess liquid. Applying an adhesive layer (according to step (c) of the method according to the present invention): The adhesive tape was applied manually to the front face of the multilayer assembly as obtained in step (b) using manual gentle pressure. The manual gentle pressure was performed by applying a pressure of 100 to 500g on the front face of the adhesive tape, which corresponds to a pressure of 1 to 5 Pa when said adhesive layer was applied onto the front face of the multilayer assembly. While attached to the tape, the backside of the Cu foil was swiped with a brush using a 0.1 M APS solution in order to mechanically and chemically remove residues, e.g. residues from the lower quality graphene grown on the back face of the Cu foil during the CVD-process. Etching away the Cu foil (according to step (d) of the method according to the present invention): The Cu foil was completely etched away by placing the multilayer assembly as obtained in step (c) onto a freshly prepared 0.1 M APS solution, backside down. Etching was performed at room temperature during 12h. No Cu was visually seen after the completion of the etching away. The sample was successively picked up from the solution, sprayed with deionized water and dried with a nitrogen spray. Transferring onto a silicon wafer (according to step (e) of the method according to the present invention): The back face of the multilayer assembly as obtained in step (d) was pressed manually under gentle pressure to a silicon wafer such as SiO2- based SOI, or Si(111) so that the graphene could adhere uniformly to the wafer. The manual gentle pressure was performed by applying a pressure of 100 to 500g on the front face of the adhesive tape, which corresponds to a pressure of 1 to 5 Pa when said adhesive layer was applied onto the front face of the multilayer assembly. The silicon wafer was successively immersed in acetone at room temperature during 6h. The tape was gradually removed and the graphene coated silicon wafer rinsed with acetone to remove residues. Sample evaluation The graphene coating, adhered on SiO2-based SOI wafers was investigated by optical microscopy and scanning electron microscopy. The morphology of the graphene coating, the presence of structural defects as well as the presence of residues were analysed over an area of 3x4 mm2. Within this area, a combination of micrographs with different magnifications was taken. Unless specified otherwise, the examples were performed according to the steps as described into detail here above in the order, as outlined in Table 1. Table 1: Step (a) CVD-graphene + optional PMMA coating Step (b) Partial etching Step (c) Applying an adhesive layer Step (d) Etching away Step (e) Transferring Examples 1-4 (E1-E4) and comparative examples 1 and 2 (CE1-CE2) Examples 1-4 (E1-E4) were performed according to Table 1 and for each experiment, a PMMA coating was applied. The etching time of the partial etching step was varied between 5 and 45 minutes. The thickness of the copper foil after etching (T2) was determined by gravimetry. In each example, the thickness of the copper foil before etching (T1) was 25 µm. In comparative examples 1 and 2 (CE1-CE2), the steps as listed in Table 1 and described into detail here above were performed, however, in CE1, the partial etching according to step (b) was not performed. In CE2, the etching time in step (b) was 60 minutes, which results in the complete etching away of the Cu layer.skcar2 cEC0Sro y6 0 0EjO n Y a N a m M y na M gsni kcha crc1 telro yEOCijO n atrN a N a m M )abp y(o n N a p M etsinsnkcioa4 tcrcEud54 461OroSe m NE oeirnYmSssw e nenoiFkc tia ht luaev3geEar030104elO OSE O ev pN NYN a m danSa e mit sgkca nr2 ih cEct517186OroSE O e NinYN la m itrw aePFskc satrcc1refE 52288O oeO NdinrN m o wineM F)e)2mµ)s2,%tcimt )T( (gT( gniin efeytinso e gin ssni ss hcdte)1 sdlmrisunihcmeh(nkcte n eskr sTlefdooFaruofiedhise tE iceetr tcnda hr ichf puUR Tetf Taxe ra(tS The results in Table 2 show that all the examples E1-E4 in which the metallic layer was partially etched during step (b), did result in a graphene layer, uniformly adhered to SiO2-based SOI wafers, without many major cracks, without many residues and without folds. The examples in which the metallic layer was not partially etched (CE1) or completely etched away in step (b) (CE2) did result in a non-uniformly adhered graphene layer exhibiting structural defects, folds and residues. Example 5 (E5) and comparative example 3 (CE3) Example 5 (E5) was performed as E3 (detailed here above), except that the optional PMMA layer in step (a) was not applied. Comparative example 3 (CE3), was performed as E5, however the partial etching step according to step (b) was not performed. Table 3 E3 E5 CE3 Partial etching time and average thickness reduction in step (b) Etching time (min)30 30Thickness (T2) after etching (µm)10 10No partial etching Thickness (T2) after etching (% 40 40 of T1) Sample evaluation Folds NO NO YES Structural defects NO NOMany majorcracks Uniformity adhesionYES YES NOResidues NO NO Many The results in Table 3 show that the example E5, in which the metallic layer was partially etched during step (b), did result in a graphene layer, uniformly adhered to SiO2-based SOI wafers, without many major cracks, without many residues and without folds. The example in which the metallic layer was not partially etched (CE3) did result in a non-uniformly adhered graphene layer exhibiting structural defects, folds and residues. In example 6 (E6), an embodiment of the present invention is exemplified for the manufacturing of object coated with a Hexagonal Boron Nitride (h-BN) coating. E6 was performed as E3 (detailed here above) except that the 2D-material in step (a) was a CVD-grown h-BN instead of graphene and that the transfer according to step (e) was performed on a silicon wafer of Si(111) from which the native oxide layer had been removed by outgassing and annealing in ultra-high vacuum. The h-BN coating, adhered on the silicon wafer was investigated by scanning electron microscopy. The morphology of the h-BN coating, the presence of structural defects as well as the presence of residues were analysed over an area of 3x4 mm2. Within this area, a combination of micrographs with different magnifications was taken. It was found that the h-BN films are uniformly adhered to the silicon wafer and no cracks or residues were observed. In addition, scanning tunnelling microscopy (STM) measurements were taken with atomic resolution as well as low-energy electron diffraction (LEED) measurements of the clean h-BN films on the silicon wafer. Both STM and LEED measurements did confirm the hexagonal structure of the h-BN coating. The graphene coating adhered on SiO2-based SOI wafers, which was obtained from example 3 (E3), was investigated by different analytical techniques which are well known in the art to evaluate the quality of 2D-materials and graphene layers more particularly. The sheet electrical resistance, electrical resistivity and electrical conductivity of the graphene coating adhered to SiO2-based SOI wafers manufactured in example 4 were measured using the four-probe method: Table 4 Sheet electrical resistance (^ / ^) 450 Electrical resistivity (^m) 1.5 x 10-7Electrical conductivity (1 / ^m) 6.7 x 106The results in table 4 show that the adhered graphene coating has excellent electrical properties. STM measurements were taken with atomic resolution as well as LEED measurements. Both STM and LEED measurements did confirm the hexagonal structure of the graphene coating adhered to the silicon wafer. Fast Fourier Transform (FFT) analysis of the STM images confirmed the high crystallinity of the graphene coating. X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES) and Raman spectroscopy of the graphene coating adhered to the silicon wafer did confirm its high crystalline quality and low level of defects. Example 8 (E8) The hexagonal boron nitride (h-BN) coating adhered on SiO2- based SOI wafers, which was obtained from example 6 (E6), was investigated by different analytical techniques which are well known in the art to evaluate the quality of 2D-materials and hexagonal boron nitride (h-BN) layers more particularly. SEM measurements and STM measurements were taken with atomic resolution as well as LEED measurements. SEM, STM and LEED measurements did confirm the cleanliness and the high crystalline quality of the hexagonal boron nitride (h-BN) coating adhered to the silicon wafer. Fast Fourier Transform (FFT) analysis of the STM images confirmed the hexagonal structure of the hexagonal boron nitride (h-BN) coating. X-ray photoelectron spectroscopy (XPS) of the hexagonal boron nitride (h-BN) coating adhered to the silicon wafer confirmed the stoichiometry B:N of 1:1 of the hexagonal boron nitride (h-BN) structure.

Claims

CLAIMS 1. A method for manufacturing an object comprising at least one surface wherein at least part of said surface is adhered to at least one 2D-material layer, wherein the 2D-material is graphene or hexagonal boron nitride, said method comprising the successive steps of: (a) providing a multilayer assembly having a front face and a back face comprising, from back to front: o at least one metallic layer (layer L1, herein after) wherein the layer L1 has a predetermined average thickness (average thickness T1, herein after), o at least one 2D-material layer, and o optionally at least one polymer layer (layer L2, herein after), (b) reducing the average thickness T1 to an average thickness T2 by subjecting layer L1 to an etching step, wherein the average thickness T2 is ranging from 5% to 95% of the average thickness of T1, (c) applying at least one adhesive layer onto at least part of the front face of the multilayer assembly, (d) etching away the layer L1 having the average thickness T2 of the multilayer assembly as obtained in step (c), and (e) transferring at least part of the 2D-material layer onto at least part of a surface of an object.

2. The method according to claim 1, wherein the average thickness T1 of the layer L1 is ranging from 4.0 µm to 110.0 µm, preferably from 8.0 µm to 90.0 µm, preferably from 10.0 µm to 60.0 µm, preferably from 15.0 µm to 40.0 µm, and more preferably from 20.0 to 30.0 µm.

3. The method according to claim 1 or claim 2, wherein the layer L1 of the multilayer assembly is made from one or more than one metal selected from the group consisting of Copper (Cu), Nickel (Ni), Ruthenium (Ru), Iridium (Ir), Platinum (Pt), Cobalt (Co), Palladium (Pd), Rhenium (Re), Gold (Au), andSilver (Ag), preferably the metal is Copper (Cu) or Nickel (Ni), more preferably the metal is Copper (Cu).

4. The method according to any one of claims 1 to 3, wherein the multilayer assembly of step (a) is prepared by the method comprising the steps of:

1. providing the layer (L1), having an average thickness T1; 2. applying the at least one 2D-material layer, to at least one side of the layer (L1); and 3. optionally, applying the layer (L2), to the at least one 2D- material layer.

5. The method according to any one of claims 1 to 4, wherein the average thickness T1 of the layer L1 is reduced to an average thickness T2, said average thickness T2 is from 10.0 % to 90.0 % of the average thickness of T1, more preferably from 20.0 % to 80.0 % of the average thickness of T1, more preferably from 40.0 % to 70.0 % of the average thickness of T1, most preferably from 50.0 % to 65.0 % of the average thickness of T1.

6. The method according to any one of claims 1 to 5, wherein step (b) is carried out by wet chemical etching.

7. The method according to any one of claims 1 to 6, wherein step (b) is carried out by dipping the multilayer assembly in contact with at least one etching solution, said etching solution being an aqueous etching solution selected from the group consisting of ammonium persulfate ((NH4)2S2O8), hydrofluoric acid (HF), Iron(III) nitrate (Fe(NO3)3), iron(III) chloride (FeCl3), Copper(II) chloride (CuCl2), hydrogen peroxide (H2O2), copper(II) sulfate (CuSO4), hydrochloric acid (HCl), hydrobromic acid (HBr), nitric acid (HNO3), sulfuric acid (H2SO4), sodium hydroxide (NaOH), phosphoric acid (H3PO4) and combinations thereof.

8. The method according to claim 7, wherein the etching solution is anaqueous ammonium persulfate solution with a concentration between 0.01 M and 1.00 M, preferably between 0.05 M and 0.50 M, more preferably between 0.075 M and 0.200 M.

9. The method according to any one of claims 1 to 8, wherein the adhesive layer of step (c), comprises one or more adhesive material selected from the group consisting of acrylic based adhesives, silicon based adhesives, epoxy adhesives, polyurethane adhesives, polyimide adhesives, and cyanoacrylates, preferably the adhesive material is acrylic based adhesive, wherein the adhesive material is preferably applied on onto one substrate carrier selected from polyvinylchloride (PVC) foils or polyethylene terephthalate (PET) foils, preferably the substrate carrier is a polyvinylchloride foil.

10. The method according to any one of claims 1 to 9, wherein step (d) is carried out by wet chemical etching.

11. The method according to any one of claims 1 to 10, wherein step (d) is carried out by dipping the multilayer assembly in contact with at least one etching solution, said etching solution being an aqueous etching solution selected from the group consisting of ammonium persulfate ((NH4)2S2O8), hydrofluoric acid (HF), Iron(III) nitrate (Fe(NO3)3), iron(III) chloride (FeCl3), Copper(II) chloride (CuCl2), hydrogen peroxide (H2O2), copper (II) sulfate (CuSO4), hydrochloric acid (HCl), hydrobromic acid (HBr), nitric acid (HNO3), sulfuric acid (H2SO4), sodium hydroxide (NaOH), phosphoric acid (H3PO4) and combinations thereof.

12. The method according to claim 11, wherein the etching solution is an aqueous ammonium persulfate solution with a concentration between 0.01 M and 1.00 M, preferably between 0.05 M and 0.50 M, more preferably between 0.075 M and 0.200 M.

13. The method according to any one of claims 1 to 12, wherein step (e) is carried out by dry transfer by applying manual gentle pressure on the front sideof the adhesive layer.

14. The method according to any one of claims 1 to 13, wherein step (e) is subsequently followed by a step of immersion of said object in a solvent, wherein the solvent is preferably selected from the group consisting of ethyl acetate, methyl ethyl ketone, and acetone, more preferably the solvent is acetone.

15. The method according to any one of claims 1 to 14, wherein the 2D- material is graphene.

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