阅读说明：本技术 一种二维过渡金属硫属化合物薄膜大面积转移的方法及其应用 (Large-area transfer method of two-dimensional transition metal chalcogenide thin film and application thereof ) 是由 王欣然 李卫胜 施毅 于 2019-09-10 设计创作，主要内容包括：本发明公开一种二维过渡金属硫属化合物薄膜大面积转移的方法及其应用,该方法为：制备大面积二维过渡金属硫属化合物薄膜；采用范德瓦尔斯外延生长技术和原子层沉积技术在过渡金属硫属化合物薄膜表面依次沉积单层有机染料分子薄膜和介电质薄膜,再涂覆一层聚合物薄膜；利用水渗透分离的原理,分离得到过渡金属硫属化合物/单层有机染料分子/介电质/聚合物复合薄膜,与目标衬底结合,去除聚合物薄膜,即完成转移。转移的二维过渡金属硫属化合物薄膜具有大面积的完整性及无污染的界面。转移的二维过渡金属硫属化合物/单层有机染料分子薄膜-介电质薄膜可用作电子器件的沟道层和介电层,具有极低的漏电和界面态,可有效降低电子器件工作电压。(The invention discloses a method for large-area transfer of a two-dimensional transition metal chalcogenide film and application thereof, wherein the method comprises the following steps: preparing a large-area two-dimensional transition metal chalcogenide thin film; sequentially depositing a single-layer organic dye molecular film and a dielectric film on the surface of the transition metal chalcogenide film by adopting a Van der Waals epitaxial growth technology and an atomic layer deposition technology, and then coating a layer of polymer film; by using the principle of water permeation separation, the transition metal chalcogenide/single-layer organic dye molecule/dielectric substance/polymer composite film is obtained by separation, and is combined with a target substrate to remove the polymer film, thus completing the transfer. The transferred two-dimensional transition metal chalcogenide thin film has large area integrity and a contamination-free interface. The transferred two-dimensional transition metal chalcogenide/single-layer organic dye molecule thin film-dielectric thin film can be used as a channel layer and a dielectric layer of an electronic device, has extremely low leakage and interface states, and can effectively reduce the working voltage of the electronic device.)

1. A method for large area transfer of a two-dimensional transition metal chalcogenide thin film, comprising the steps of:

(1) preparing a large-area two-dimensional transition metal chalcogenide thin film;

(2) sequentially forming a single-layer organic dye molecule film, a dielectric film and a polymer film on the surface of the two-dimensional transition metal chalcogenide film by adopting a Van der Waals epitaxial growth technology, an atomic layer deposition technology and a surface coating technology;

(3) immersing the stacked structure obtained in the step (2) in water to separate the two-dimensional transition metal chalcogenide/single-layer organic dye molecule/dielectric substance/polymer composite film from the growth substrate;

(4) and combining the separated composite film with a target substrate, and removing the polymer film to finish the transfer of the large-area two-dimensional transition metal chalcogenide/single-layer organic dye molecule/dielectric composite film.

2. The method of claim 1, wherein the two-dimensional transition metal chalcogenide thin film is large-area transferredThe film is a binary compound MX formed by transition metal M and chalcogen X₂Wherein the binary compound MX₂An alloy compound selected from one or more of molybdenum disulfide, molybdenum diselenide, tungsten disulfide, tungsten diselenide, hafnium disulfide, zirconium disulfide, rhenium diselenide, platinum disulfide, platinum diselenide, molybdenum ditelluride and tungsten ditelluride.

3. The method for large area transfer of a two-dimensional transition metal chalcogenide thin film according to claim 1, wherein in step (1), the method for preparing a large area two-dimensional transition metal chalcogenide thin film is a chemical vapor deposition method, a physical vapor deposition method, an atomic layer deposition method or a metal organic chemical vapor deposition method.

4. The method for large area transfer of a two-dimensional transition metal chalcogenide thin film according to claim 1, wherein in the step (2), the method for growing the organic dye molecular thin film by using van der waals epitaxial growth technology comprises: the two-dimensional transition metal chalcogenide thin film is used as a substrate, organic dye molecules are used as a growth source, the two-dimensional transition metal chalcogenide thin film is placed in vacuum evaporation equipment, after the equipment is vacuumized, the heating is carried out, the organic dye molecules are evaporated, and a single-layer organic dye molecule thin film is formed on the surface of the two-dimensional transition metal chalcogenide thin film in a deposition mode.

5. The method for large-area transfer of a two-dimensional transition metal chalcogenide film according to claim 1 or 4, wherein in the step (2), the organic dye molecular film is any one of 3,4,9, 10-perylenetetracarboxylic dianhydride and its derivatives, 3,4,9, 10-perylenetetracarboxylic diimide and its derivatives, rubrene and its derivatives, and N, N-ditolylberyleneimide and its derivatives.

6. The method for large area transfer of a two-dimensional transition metal chalcogenide thin film according to claim 1, wherein in the step (2), the dielectric thin film is an insulating thin film that can be prepared by an atomic layer deposition technique; the polymer film is a molecular film of any one of polymethyl methacrylate, polyethylene, polypropylene, polycarbonate, polyvinyl alcohol, polystyrene and polyimide.

7. The method for large area transfer of a two-dimensional transition metal chalcogenide thin film according to claim 1, wherein the surface coating technique in step (2) is spin coating, drop coating, printing, blade coating, spray coating, physical deposition or chemical growth method.

8. The method for large-area transfer of a two-dimensional transition metal chalcogenide thin film as claimed in claim 1, wherein in the step (4), the two-dimensional transition metal chalcogenide/monolayer organic dye molecule/dielectric/polymer composite thin film after separation is bonded, pressed or adhered to the target substrate; the method for removing the polymer film is stripping, dissolving, heating or chemical reaction.

9. Use of a two-dimensional transition metal chalcogenide thin film transferred by the method of claim 1 for electronic or optoelectronic devices.

10. Use according to claim 9, characterized in that the two-dimensional transition metal chalcogenide/monolayer organic dye molecule/dielectric composite film transferred onto a target substrate by the method of claim 1 is used as channel and dielectric layer for electronic or optoelectronic devices.

Technical Field

The invention relates to a method for large-area transfer of a two-dimensional transition metal chalcogenide film and application thereof in preparing electronic or optoelectronic devices, belonging to the technical field of two-dimensional material electronic devices.

Background

Since the mole law was proposed by gorden-mole, the number of devices integrated on an integrated circuit chip doubled every 18 months, and the performance of a microprocessor doubled every 18 months; at the same time, the size of transistors is also shrinking. Currently, commercial chips have been developed to 10 nm nodes. However, as the scale approaches the quantum limit, the continuous scaling process of the transistor is restricted by the problems of electric leakage and power consumption caused by the short channel effect. The study of new two-dimensional materials is one of the important approaches to continue moore's law. Transition metal chalcogenides are a class of two-dimensional semiconductor materials that have a bandgap of 1-2eV, good air stability and process compatibility, and can be synthesized by chemical vapor deposition over large areas, and are therefore best suited for logic device integration. Due to the thickness of the material at the atomic level, the material can still maintain excellent performance in a short-channel device, and particularly, the preparation of a 1-nanometer gate length device shows the advantages which cannot be achieved by the traditional electronic device.

Currently, one of the significant challenges limiting the development of two-dimensional transition metal chalcogenide electronic and optoelectronic devices is the integration of large-area, low interface state dielectric layers and lossless transfer. The two-dimensional transition metal chalcogenide has the thickness of only a few atoms, and has the problems of easy breakage, easy curling, difficult control, dirty interface and the like when being directly transferred, so that the development and the application of the two-dimensional transition metal chalcogenide in the field of electronic devices are inhibited. At present, the mainstream transfer method needs to spin-coat or attach a layer of polymer film on the surface of the two-dimensional transition metal chalcogenide, and the polymer film is used as a supporting layer to protect the two-dimensional transition metal chalcogenide film from deformation and damage during transfer; then, etching the growth substrate by using the etching liquid to realize the separation of the two-dimensional transition metal chalcogenide film and the growth substrate, wherein the two-dimensional transition metal chalcogenide film can be doped and damaged to a certain extent in the process; after the two-dimensional transition metal chalcogenide thin film is transferred onto a target substrate, the polymer thin film needs to be removed by an organic solvent such as acetone or a thermal annealing method. However, the polymer film is very difficult to remove, and the transferred two-dimensional transition metal chalcogenide thin film still has a large amount of polymer residues, which greatly reduces the interface quality.

The methods disclosed and reported at present are difficult to realize large-area, low-interface state and damage-free transition metal chalcogenide thin films. Based on this, the inventors have developed a method for realizing the transfer of a large-area two-dimensional transition metal chalcogenide thin film using a single-layer organic dye molecule thin film-dielectric thin film as a support layer.

Disclosure of Invention

The purpose of the invention is as follows: aiming at the problems of easy damage, interface residue and the like existing in the transition metal chalcogenide thin film transferred in the prior art, the invention provides a method for transferring a two-dimensional transition metal chalcogenide thin film in a large area and provides application of the two-dimensional transition metal chalcogenide thin film transferred by the method in electronic or photoelectronic devices.

The technical scheme is as follows: the invention relates to a method for large-area transfer of a two-dimensional transition metal chalcogenide film, which comprises the following steps:

(1) preparing a large-area two-dimensional transition metal chalcogenide thin film;

(2) sequentially forming a single-layer organic dye molecule film, a dielectric film and a polymer film on the surface of the two-dimensional transition metal chalcogenide film by adopting a Van der Waals epitaxial growth technology, an atomic layer deposition technology and a surface coating technology;

(3) immersing the stacked structure obtained in the step (2) in water to separate the composite film of the two-dimensional transition metal chalcogenide film/single-layer organic dye molecule film/dielectric film/polymer film from the growth substrate;

(4) and combining the separated two-dimensional transition metal chalcogenide/single-layer organic dye molecule/dielectric substance/polymer composite film with a target substrate, and removing the polymer film to finish the transfer of the large-area two-dimensional transition metal chalcogenide/single-layer organic dye molecule/dielectric substance composite film.

Wherein the two-dimensional transition metal chalcogenide is transition metal M and chalcogen element X as MX₂The two-dimensional transition metal chalcogenide thin films prepared in the step (1) are compounds MX formed by chemical composition₂A film of (a); binary compound MX₂Including but not limited to molybdenum disulfide, molybdenum diselenide, tungsten disulfide, tungsten diselenide, hafnium disulfide, zirconium disulfide, rhenium diselenide, platinum disulfide, platinum diselenide, molybdenum ditelluride, tungsten ditelluride, or a mixture of two or more thereof. Specifically, the method for preparing the two-dimensional transition metal chalcogenide thin film includes, but is not limited to, chemical vapor deposition, physical vapor deposition, atomic layer deposition or metal organic chemical vapor deposition, and the growth substrate used in the preparation process includes, but is not limited to, silicon oxide, sapphire, glass, gallium nitride, silicon carbide, diamond, and the like. Taking the growth of the molybdenum disulfide film as an example, taking molybdenum oxide powder and sulfur powder as precursor reactants, taking sapphire as a substrate, and placing the reactants in a tube furnace at intervalsAnd vacuumizing the tube furnace to be thick, introducing argon as a carrier gas, adding the furnace body to the temperature of 600-1000 ℃, evaporating and reacting the precursor reactant, and growing for a certain time to form a large-area transition metal chalcogenide film on the surface of the sapphire.

In the step (2), the organic dye molecular film includes, but is not limited to, a molecular film of any one of 3,4,9, 10-perylene tetracarboxylic dianhydride and its derivatives, 3,4,9, 10-perylene tetracarboxylic diimide and its derivatives, rubrene and its derivatives, and N, N-xylyl perylene imide and its derivatives. The dielectric film is an insulating film that can be produced by an atomic layer deposition technique, and is preferably an oxide film including an aluminum oxide film, a hafnium oxide film, a zirconium oxide film, a titanium oxide film, a lanthanum oxide film, or the like. The polymer film may be a molecular film of any of organic polymers, and is preferably polymethyl methacrylate, polyethylene, polypropylene, polycarbonate, polyvinyl alcohol, polystyrene, polyimide, or the like.

Preferably, the method for growing the organic dye molecular film in the step (2) comprises the following steps: the two-dimensional transition metal chalcogenide thin film is used as a substrate, organic dye molecules are used as a growth source, the two-dimensional transition metal chalcogenide thin film is placed in vacuum evaporation equipment, after the equipment is vacuumized, the heating is carried out, the organic dye molecules are evaporated, and a single-layer organic dye molecule thin film is formed on the surface of the two-dimensional transition metal chalcogenide thin film in a deposition mode. Preferably, the temperature of the vacuum evaporation equipment is heated to the position of the growth source to be 150-300 ℃, the temperature is kept for 0.1-3 h, organic dye molecules are evaporated, and a single-layer organic dye molecule film is formed on the surface of the two-dimensional transition metal chalcogenide film through deposition.

The growth method of the dielectric film is preferably: transferring the two-dimensional transition metal chalcogenide with the single-layer organic dye molecular film to an atomic layer deposition cavity, vacuumizing, raising the temperature of the cavity to 80-200 ℃, introducing a precursor reactant, and depositing in situ on the surface of a seed layer of the two-dimensional transition metal chalcogenide to obtain the ultrathin and uniform dielectric film.

When the polymer film is grown by using the surface coating technique, the specific growth method includes, but is not limited to, spin coating, drop coating, printing, knife coating, spray coating, physical deposition or chemical growth method.

In the step (3), the product obtained in the step (2) is immersed in water, and water molecules can penetrate into the space between the two-dimensional transition metal chalcogenide film and the growth substrate by utilizing the principle of water permeation separation, so that the composite film of the two-dimensional transition metal chalcogenide film/single-layer organic dye molecule film/dielectric film/polymer film is separated from the growth substrate.

In the step (4), the two-dimensional transition metal chalcogenide/single-layer organic dye molecule/dielectric substance/polymer composite film after separation can be combined with the target substrate in a bonding, pressing or adhering mode; the method of removing the polymer film may be peeling, dissolving, heating or chemical reaction.

Since the two-dimensional transition metal chalcogenide does not directly contact the polymer thin film, the transferred two-dimensional transition metal chalcogenide thin film has a large area of integrity and a contamination-free interface. The two-dimensional transition metal chalcogenide/single-layer organic dye molecule/dielectric composite film transferred onto a target substrate can be used in electronic or optoelectronic devices, such as field effect transistors, phototransistors, tunneling transistors, memory devices, and the like; in particular, it can be used as channel and dielectric layers of electronic or optoelectronic devices.

Taking a field effect transistor as an example, the field effect transistor using the two-dimensional transition metal chalcogenide/monolayer organic dye molecule/dielectric composite thin film transferred onto a target substrate as a channel layer and a dielectric layer can be prepared by the following method:

(1) preparing a source electrode and a drain electrode on a target substrate in advance;

(2) preparing a large-area two-dimensional transition metal chalcogenide thin film on a growth substrate;

(3) sequentially forming a single-layer organic dye molecule film, a dielectric film and a polymer film on the surface of the two-dimensional transition metal chalcogenide film by adopting a Van der Waals epitaxial growth technology, an atomic layer deposition technology and a surface coating technology;

(4) immersing the stacked structure obtained in the step (3) in water to separate the two-dimensional transition metal chalcogenide/single-layer organic dye molecule/dielectric substance/polymer composite film from the growth substrate; combining the separated composite film with a target substrate, removing the polymer film, and obtaining a two-dimensional transition metal chalcogenide/single-layer organic dye molecule/dielectric composite film on the target substrate;

(5) and preparing a top gate electrode to obtain the required field effect transistor.

In the case of producing a field effect transistor device, the raw material selection ranges of the two-dimensional transition metal chalcogenide thin film, the organic dye molecule thin film and the dielectric thin film and the process control procedures of the steps (2) to (4) are the same as those in the above-described method for large-area transfer of a two-dimensional transition metal chalcogenide thin film.

The invention principle is as follows: a monolayer organic dye molecule film-dielectric film is introduced between the polymer film and the two-dimensional material, so that the combination among the polymer film, the two-dimensional material and a target substrate is improved, and the structural integrity of the large-area two-dimensional transition metal chalcogenide film is improved; in addition, due to the blocking and protecting effects of the single-layer organic dye molecule film and the dielectric film, the transfer medium is easier to remove, the residue of the polymer film is obviously reduced, the interface of the two-dimensional transition metal chalcogenide film is cleaner, and the interface state is greatly reduced.

Has the advantages that: compared with the prior art, the invention has the advantages that: (1) compared with the traditional transfer method using a polymer as a supporting layer, the invention integrates a single-layer organic dye molecule film-dielectric film on the surface of the two-dimensional transition metal chalcogenide film by the Van der Waals epitaxial growth technology and the atomic layer deposition technology, which can ensure that the two-dimensional transition metal chalcogenide film has a complete and clean interface; meanwhile, the operation method of the invention has low cost and simple processing realization; (2) compared with the traditional wet transfer method, the method avoids doping and damage to the two-dimensional transition metal chalcogenide film by using a water permeation separation method; (3) the monolayer organic dye molecule film-dielectric film on the two-dimensional transition metal chalcogenide film transferred by the method can be used as a dielectric layer of a two-dimensional transition metal chalcogenide film electronic device, has an extremely low interface state, can obviously reduce the subthreshold swing and working voltage of the device, is suitable for electronic and photoelectronic device applications in various forms, including a field effect transistor, a photoelectric transistor, a tunneling transistor, a storage device and the like, and can effectively reduce the leakage amount and relieve the short channel effect if the field effect transistor device prepared by the method is adopted; and may be used in large scale integrated circuit applications.

Drawings

FIG. 1 is a flow chart of a method for large area transfer of a two-dimensional transition metal chalcogenide thin film of the present invention;

FIG. 2 is a composite structure of PVA film/alumina film/ single layer 3,4,9, 10-perylene tetracarboxylic diimide molecular film/molybdenum disulfide film/glass prepared in example 1;

FIG. 3 is a schematic view showing the complete separation of the composite film of PVA film/alumina film/single layer of 3,4,9, 10-perylene tetracarboxylic diimide molecule film/molybdenum disulfide film from the glass in example 1;

FIG. 4 is a composite film of a molybdenum disulfide film/a single layer of a 3,4,9, 10-perylene tetracarboxylic diimide molecular film/an aluminum oxide film/a polyvinyl alcohol film transferred onto a target substrate in example 1;

FIG. 5 is an atomic force microscope photomicrograph of the molybdenum disulfide film/ monolayer 3,4,9, 10-perylene tetracarboxylic diimide molecular film/alumina film composite film transferred onto the target substrate in example 1, at a scale bar of 6 μm;

FIG. 6 is a molybdenum diselenide thin film/ single layer 3,4,9, 10-perylenetetracarboxylic dianhydride molecular thin film/alumina thin film/polymethyl methacrylate thin film composite thin film transferred onto a target substrate in example 2;

FIG. 7 is an atomic force microscope image of the molybdenum diselenide film/ single layer 3,4,9, 10-perylenetetracarboxylic dianhydride molecular film/aluminum oxide film composite film transferred onto the target substrate in example 2, at a scale bar of 4 μm;

FIG. 8 is an optical microscope photograph of the molybdenum disulfide film/ monolayer 3,4,9, 10-perylene tetracarboxylic diimide molecular film/hafnium oxide film composite film transferred onto the target substrate in example 3, with a scale bar of 200 μm;

fig. 9 is a photomicrograph of source and drain electrodes formed on a silicon oxide substrate in example 4;

fig. 10 is a physical diagram of a molybdenum disulfide top-gate transistor prepared on a silicon oxide substrate in example 4, which is respectively composed of a source-drain electrode, a top-gate electrode, a transferred molybdenum disulfide film (as a channel layer) and a single-layer organic 3,4,9, 10-perylene tetracarboxylic dianhydride molecular film-hafnium oxide film (as a dielectric layer);

FIG. 11 is a transfer characteristic curve for a typical molybdenum disulfide transistor prepared in example 4, with source-drain voltage at 0.5 volts;

figure 12 is an output characteristic curve for a typical molybdenum disulfide transistor prepared in example 4.

Detailed Description

The technical scheme of the invention is further explained by combining the attached drawings.

Referring to fig. 1, the method for large-area transfer of a two-dimensional transition metal chalcogenide thin film according to the present invention comprises the steps of:

(1) preparing a large-area two-dimensional transition metal chalcogenide thin film;

(2) sequentially forming a single-layer organic dye molecule film, a dielectric film and a polymer film on the surface of the two-dimensional transition metal chalcogenide film by adopting a Van der Waals epitaxial growth technology, an atomic layer deposition technology and a surface coating technology; wherein, the monolayer organic dye molecular film-dielectric film is used as a supporting layer, and the polymer film is used as a protective layer;

(3) immersing the stacked structure obtained in the step (2) in water to separate the two-dimensional transition metal chalcogenide film/single-layer organic dye molecule film-dielectric film/polymer film composite film from the growth substrate;

(4) and combining the separated composite film with a target substrate, and removing the polymer film to finish the transfer of the large-area two-dimensional transition metal chalcogenide/single-layer organic dye molecule/dielectric composite film.

The two-dimensional transition metal chalcogenide thin film/single-layer organic dye molecule thin film/dielectric thin film transferred to the target substrate can be used for preparing electronic and photoelectric devices such as field effect transistors, photoelectric transistors, tunneling transistors, memory devices and the like. Compared with the dielectric layer in the traditional process, the single-layer organic dye molecular film-dielectric film used as the dielectric layer of the electronic device has the following two advantages: firstly, a monolayer organic dye molecule film-dielectric film is formed on an initially synthesized two-dimensional transition metal chalcogenide film, and the initially synthesized two-dimensional transition metal chalcogenide film has the flatness of atomic level and provides an excellent template for forming a high-quality dielectric layer; secondly, a very clean and pollution-free contact interface is formed between the monolayer organic dye molecule film-dielectric film formed in situ and the two-dimensional transition metal chalcogenide film, so that the interface state density is greatly reduced, and the performance and the stability of an electronic device can be remarkably improved.