CN115807215A - A MOCVD device and method for preparing two-dimensional crystal materials based on ultrasonic atomization - Google Patents

Abstract

The invention discloses an MOCVD device and method for preparing two-dimensional crystal materials based on ultrasonic atomization, which belongs to the field of preparation of two-dimensional crystal materials. The atomization device is used to place the liquid first raw material, and is used to directly atomize the first raw material to generate the vapor of the first raw material; the second atomization device is used to place the solid second raw material, and is used to heat the second raw material To generate the vapor of the second raw material; the technical solution of the present invention can effectively solve the problem that the source is liquefied into large droplets during transportation and the static gas mixing effect is poor during the preparation process of the two-dimensional crystal material, so that the material preparation accuracy is high and the product uniformity And the advantages of good repeatability and wide application range of chemical vapor deposition equipment.

Description

A MOCVD device and method for preparing two-dimensional crystal materials based on ultrasonic atomization

technical field

The invention belongs to the field of preparation of two-dimensional crystal materials, and in particular relates to an MOCVD device and method for preparing two-dimensional crystal materials based on ultrasonic atomization.

Background technique

MOCVD (Metal-Organic Chemical Vapor Deposition, metal-organic chemical vapor deposition) is a chemical vapor phase epitaxy growth technology developed on the basis of vapor phase epitaxy (VPE) technology. In 1968, it was proposed by H. M. Manasevit of Rockwell Corporation of the United States. It has developed rapidly since the 1980s, and has shown great advantages in the preparation of two-dimensional semiconductor heterojunction materials. Compounds and hydrides of group V and group VI elements are used as source materials, which are carried by the carrier gas and transported into the reaction chamber, where corresponding chemical reactions occur on the surface of the heated substrate to generate various group III-V and group II-VI compounds The two-dimensional atomic crystal material is deposited on the substrate to obtain the corresponding epitaxial two-dimensional crystal film material.

At present, the transmission of solid or liquid sources by MOCVD is mostly heated and evaporated by a water bath, and then transported to the reaction chamber with a carrier gas. This process limits the types of non-gaseous sources, and it is easy to cause the sources to condense into small liquids during transportation. Dropping or source adsorption tube wall phenomenon, resulting in low utilization of source material. In addition, most of the gas mixers used in the field of two-dimensional crystal material growth are static mixers. The working principle is that several gases simply collide through a closed space and then mix. Problems with poor mixing. Therefore, it is necessary to design advanced organic source delivery devices and dynamic gas mixing devices to meet the needs of MOCVD for large-area production of two-dimensional atomic crystal semiconductor processes.

Contents of the invention

The invention provides a MOCVD device and method for preparing two-dimensional crystal materials based on ultrasonic atomization, which has an advanced organic source transmission device and a dynamic gas mixing device, which solves the problem of poor gas mixing effect and low utilization rate of source materials in the prior art The problem.

In order to achieve the above object, the present invention adopts the following technical solutions:

A MOCVD device for preparing two-dimensional crystal materials based on ultrasonic atomization, comprising: a gas source channel, a non-gaseous source atomization channel, an ultrasonic atomization nozzle, and a reaction chamber; the outlet of the gas source channel and the non-gaseous source atomization channel The inlets of the ultrasonic atomizing nozzles are respectively connected, the outlet of the ultrasonic atomizing nozzles is located at the top of the reaction chamber, and the bottom of the reaction chamber is located directly below the ultrasonic atomizing nozzles to install a sample stage;

The non-gaseous source atomization channel is composed of a plurality of liquid source atomization channels, solid source atomization channels or two channels;

A liquid source atomization device is set in the liquid source atomization channel, and the liquid source atomization device includes a container, an ultrasonic microporous atomization sheet, a liquid-absorbing cotton, and a cover; the cover is stepped, and the bottom end is stuck in the container On the outside of the top end, an ultrasonic microporous atomizing sheet is arranged above the cover in contact with the container, a shock-absorbing rubber is arranged between the ultrasonic microporous atomizing sheet and the cover, and a carrier is arranged on the side of the cover above the ultrasonic microporous atomizing sheet. Gas inlet; the top of the cover is provided with an outlet; the liquid-absorbing cotton is located in the container, the bottom is placed in the liquid source, and the top is connected to the metal sheet of the through-hole array on the ultrasonic microporous atomization sheet; the liquid source is passed through the liquid-absorbing cotton The metal sheet transmitted to the through-hole array in the ultrasonic microporous atomizing sheet is atomized to smaller particles or even vaporized by piezoelectric ceramics driving the metal sheet to vibrate at high frequency;

A solid-state source atomization device is set in the solid-state source atomization channel, and the solid-state source atomization device includes a container, a high-temperature-resistant driver, and a cover; the cover is stepped, and the bottom end is stuck on the outside of the top of the container. A high temperature resistant ultrasonic microporous atomizing sheet is arranged above the container contact, a high temperature resistant shock absorbing block is arranged between the high temperature resistant ultrasonic microporous atomizing sheet and the cover, and the side of the cover is set above the high temperature resistant ultrasonic microporous atomizing sheet Carrier gas inlet; the top of the cover is provided with an outlet; the bottom of the container is provided with a heating base, and the solid source is placed on the heating base, and the solid source is evaporated to the through-hole array in the high-temperature-resistant ultrasonic microporous atomizing sheet by heating. The metal sheet is driven by piezoelectric ceramics to vibrate at high frequency to further atomize to smaller particles or even vaporize;

The ultrasonic atomizing nozzle includes a gas mixing chamber, a high temperature resistant ultrasonic microporous atomizing sheet, and a frustum-shaped shield; multiple air inlets are arranged on the top of the gas mixing chamber for connecting gaseous source channels and non-gaseous source mist At the outlet of the chemical channel, the bottom end protrudes to both sides to install a high temperature resistant ultrasonic microporous atomizing sheet, and a high temperature resistant shock absorber is installed between the high temperature resistant ultrasonic microporous atomizing sheet and the inner wall of the gas mixing chamber. The end is located under the high-temperature-resistant ultrasonic microporous atomizing sheet, and a frustum-shaped shield is set;

The ultrasonic microporous atomizing sheet is composed of a high-temperature-resistant annular piezoelectric ceramic and a metal sheet with a tapered hole. One end of the large hole of the tapered hole is a liquid inlet hole, and one end of a small hole is an air outlet hole. The electroceramic is attached to the side of the large hole of the metal sheet, the diameter of the large hole is 5-20 μm, and the diameter of the small hole is 1-5 μm;

The vertical distance between the small hole of the ultrasonic microporous atomizing sheet in the ultrasonic atomizing nozzle and the sample stage is 5-100 mm. The flow rate of the droplets slows down, and the droplets gather slowly in the large holes. After the ultrasonic vibration is added, the cavitation phenomenon or the micro-shock wave will cause the liquid to be atomized; that is, when the liquid source reaches the large holes or solids on the metal sheet through the absorbent cotton When the source reaches the large hole on the metal sheet through evaporation, because the piezoelectric ceramic drives the metal sheet to vibrate up and down at a frequency of MHz level, the liquid droplet and the metal sheet produce rapid relative motion, and the liquid source or the solid source of large-particle smoke enters the large hole from the small hole Rapidly ejected into fine particle smoke, the finer droplets are carried to the base of the reaction chamber by the carrier gas, and the thicker droplets are usually further gasified by the cavitation field generated on the upper surface of the vibrating metal sheet, or refluxed and accumulated on the metal sheet The large hole on the back of the sheet, the liquid droplets reaching a certain size continue to be ejected from the small hole by ultrasonic cavitation; the sample stage can be rotated and adjusted up and down, and the speed is 100-300 rpm.

The method for preparing a two-dimensional crystal material using the above-mentioned device comprises the following steps:

First, the reaction gas from a solid or liquid source is initially ultrasonically refined and sent to the top of the ultrasonic atomization nozzle through the carrier gas in the intake pipe, and is quickly sprayed into the MOCVD reaction chamber through the cone through-hole array of the atomizer. base surface. After entering the MOCVD reaction chamber, since the substrate rotates with the substrate tray, the top of the substrate can be repeatedly exposed to different reaction gases within a short accumulation range, so that the surface of the epitaxial layer maintains a uniform mixing state , which greatly improves the migration of the source on the surface of the epitaxial layer, and is especially beneficial to the growth of single-component or multi-component two-dimensional crystal materials.

The two-dimensional crystal materials include: single-element two-dimensional crystal materials boronene and graphene, transition metal chalcogen two-dimensional crystal materials MX ₂ , III-VI group two-dimensional crystal materials VX, wherein M is a transition metal element, and X is Chalcogen elements, V is the third main group element.

The solid raw materials include: sodium borohydride, lithium borohydride, potassium borohydride, sodium borodeuteride, sodium cyanoborohydride, tetramethylammonium borohydride, tetramethyltriacetoxyammonium borohydride, tri-sec-butyl Lithium borohydride, bis(triphenylphosphine) cuprous borohydride, tetrabutylammonium borohydride, triethyllithium borohydride, tri-sec-butyl lithium borohydride, tripentyl lithium borohydride, tris(3,5 -One or more mixtures of dimethyl-1-pyrazolyl)potassium borohydride, tetra-n-butylammonium borohydride, potassium triisobutylborohydride, and benzyltriphenylphosphine borohydride;

The first raw material includes: dimethyl disulfide, diethyl sulfide, diethyl diselenide, hydrogen sulfide, hydrogen selenide, sulfur, selenium, and the second raw material includes: molybdenum dimethyl dithiocarbamate , bis(tert-butylamine)bis(dimethylamine)tungsten, hexahydroxymolybdenum, hexahydroxytungsten, hexachloride tungsten, trimethylindium, trichloride indium;

The substrate is gold, silver, copper, aluminum, iridium, rubidium and other metals, or mica, quartz wafer, silicon wafer, glass, silicon carbide, silicon boride, sapphire, gallium nitride, gallium arsenide, gallium oxide, Graphene, boron nitride, molybdenum sulfide, tungsten sulfide, molybdenum selenide, tungsten selenide, antimony selenide, bismuth selenide, bismuth sulfide, bismuth telluride, antimony telluride, magnesium oxide, magnesium boride, titanium boride , calcium boride or aluminum boride and other non-metals.

The carrier gas is hydrogen, hydrogen-argon, hydrogen-nitrogen mixed gas, high-purity nitrogen, argon or hydride gas, and the flow rate of the carrier gas is less than or equal to 100 sccm.

The growth temperature of the two-dimensional crystal material is 500-1000° C., and the thickness of the two-dimensional crystal material is precisely controlled from a single atomic layer to 20 atomic layers.

Beneficial effects: the present invention provides a MOCVD device and method for preparing two-dimensional crystal materials based on ultrasonic atomization. The flow rate of the carrier gas and the flow rate of hydrogen make the source material content of the ultrasonic microporous atomization sheet per unit time be effectively controlled, thereby adjusting the amount of source material adsorbed and deposited on the substrate per unit time, so that the two-dimensional material on the substrate The nucleation and growth rate of the crystalline material can be controlled, so that the nucleation density, grain size and the time to form a continuous single-layer 2D thin film can be adjusted. The preparation method can obtain a discontinuous two-dimensional single crystal in a short time deposition, a continuous single-layer two-dimensional polycrystalline film can be obtained in a longer time growth, and a multi-layer two-dimensional crystal film can be obtained in a longer time. The method of the invention is simple and easy, solves the problems of poor gas mixing effect and low utilization rate of source materials in the prior art, and is suitable for large-scale production and high-quality preparation of two-dimensional crystal materials with uniform texture, good repeatability and precise thickness control. .

Description of drawings

Fig. 1 is a schematic structural view of the first atomization device used in the embodiment of the present invention;

Fig. 2 is a schematic structural view of a second atomization device used in an embodiment of the present invention;

Fig. 3 is a schematic structural view of an ultrasonic atomizing nozzle device used in an embodiment of the present invention;

Fig. 4 is a three-view view of the structure of the ultrasonic microporous atomizing sheet in the atomizing device used in the embodiment of the present invention;

Fig. 5 is a schematic diagram of the atomization principle of the ultrasonic microporous atomization sheet in the atomization device used in the embodiment of the present invention;

Fig. 6 is the overall structure schematic diagram of the MOCVD device used in the embodiment of the present invention;

Fig. 7 is the reaction flow diagram that the embodiment of the present invention adopts;

Among them, 1—first atomization device, 2—second atomization device, 3—ultrasonic atomization nozzle, 4—reaction chamber, 11—carrier gas inlet of the first atomization device, 12—first atomization device Cover, 13—shock-absorbing rubber, 14—ultrasonic microporous atomizing sheet, 15—container of the first atomizing device, 16—liquid absorbent cotton, 17—liquid source, 21—carrier gas inlet of the second atomizing device, 22—the cover of the second atomizing device, 23—high temperature resistant shock absorbing block, 24—high temperature resistant ultrasonic microporous atomizing sheet, 25—container of the second atomizing device, 26—solid source, 27—heating base, 31—gas state Source air inlet, 32—liquid source steam inlet, 33—solid source steam inlet, 34—air mixing chamber, 35—air mixing chamber cover, 36—high temperature resistant ultrasonic microporous atomizing sheet, 37—resistant High-temperature damping block, 38—cone-shaped shield, 41—piezoelectric ceramic sheet, 42—bottom of tapered hole, 43—metal sheet with tapered hole, 44—top of tapered hole.

Detailed ways

The present invention will be described in detail below in conjunction with accompanying drawing and specific embodiment:

As shown in Figure 6, a MOCVD device for preparing two-dimensional crystal materials based on ultrasonic atomization includes:

A gas line for the gaseous source for direct transfer of the gaseous source;

As shown in Figure 1, a first atomizing device for ultrasonic atomization of a liquid source is used to place the liquid source material in the first raw material; the first atomizing device includes a container, an ultrasonic microporous atomizing sheet, Liquid-absorbing cotton and a cover; the cover is stepped, and the bottom end is stuck on the outside of the top of the container. An ultrasonic microporous atomizing sheet is arranged above the cover in contact with the container, and an ultrasonic microporous atomizing sheet is arranged between the ultrasonic microporous atomizing sheet and the cover. Shock-absorbing rubber, the side of the cover is located above the ultrasonic microporous atomization sheet to set the carrier gas inlet; the top of the cover is provided with an outlet; the liquid-absorbing cotton is located in the container, the bottom is placed in the liquid source, and the top is connected The metal sheet of the through-hole array on the porous atomizing sheet; the liquid source is transmitted to the metal sheet of the through-hole array in the ultrasonic microporous atomizing sheet through the liquid absorbent cotton, and is driven by piezoelectric ceramics to atomize to smaller particles or even vaporize;

As shown in Figure 2, a second atomization device for thermal evaporation ultrasonic atomization of solid-state sources is used to place the second raw material, and the second atomization device includes a container, a high temperature resistant ultrasonic microporous atomization sheet, a cover The cover is stepped, the bottom end is stuck on the outside of the top of the container, a high temperature resistant ultrasonic microporous atomizing sheet is arranged above the cover in contact with the container, and a high temperature resistant ultrasonic microporous atomizing sheet is arranged between the high temperature resistant ultrasonic microporous atomizing sheet and the cover High-temperature shock-absorbing block, the side of the cover is located above the high-temperature-resistant ultrasonic microporous atomization sheet, and a carrier gas inlet is provided; one end of the carrier gas inlet is connected to the second atomization device, and the other end is directly connected to the ultrasonic atomization nozzle. The top of the cover is provided with an outlet; the bottom of the container is provided with a heating base, and the solid source is placed on the heating base, and is heated by the resistance wire at the bottom, so that the solid source evaporates to the metal sheet of the through-hole array of the ultrasonic atomization cone. Piezoelectric ceramic drives further atomization to smaller particles and even vaporization;

Both the first atomizing device and the second atomizing device are modular equipment, which can be combined freely, such as using two first atomizing devices, which can be used when both sources are liquids, such as using two A second atomizing device, which can be used in cases where both sources are solid;

As shown in Figure 3, a reaction chamber device with an ultrasonic atomization nozzle and a sample stage, the ultrasonic atomization nozzle includes a gas mixing chamber, a high temperature resistant ultrasonic microporous atomization sheet, a truncated cone shield; the gas mixing chamber A plurality of air inlets are provided at the top of the nozzle to connect the gaseous source channel and the outlet of the non-gaseous source atomization channel, and the bottom end protrudes to both sides to install a high-temperature-resistant ultrasonic microporous atomizing sheet, and the high-temperature-resistant ultrasonic microporous atomizing sheet A high-temperature-resistant shock absorber is installed between the gas-mixing inner wall and the bottom of the gas-mixing chamber is located below the high-temperature-resistant ultrasonic microporous atomizing sheet, and a frustum-shaped shield is set;

As shown in Figure 4, the ultrasonic microporous atomizing sheet is composed of a high-temperature-resistant annular piezoelectric ceramic and a metal sheet with a tapered hole. Pores, the annular piezoelectric ceramics are pasted on the side of the coarse holes of the metal sheet, the diameter of the large holes is 5-20 μm, and the diameter of the small holes is 1-5 μm; the driving method of the ultrasonic microporous atomizing sheet is electric field drive, As shown in Figure 4, the piezoelectric ceramics and the metal sheet are respectively connected to the positive and negative poles of the AC power supply. Due to the change of the current direction, the high-frequency deformation of the piezoelectric ceramics in the vertical direction will drive the metal sheet to vibrate up and down at high frequencies. The vertical distance between the small hole of the ultrasonic microporous atomizing sheet in the atomizing nozzle and the sample stage is 5-100 mm, as shown in Figure 5, the working principle of the ultrasonic microporous atomizing sheet is: when the droplet passes through the large hole Flowing to the small hole, the flow velocity of the droplet will become faster, and the flow velocity of the droplet will slow down when flowing from the small hole to the large hole, and slowly gather in the large hole, plus ultrasonic vibration, it will produce cavitation phenomenon or micro-shock wave to atomize the liquid; That is, when the liquid source reaches the large hole on the metal sheet through the absorbent cotton or the solid source reaches the large hole on the metal sheet through evaporation, since the piezoelectric ceramic drives the metal sheet to vibrate up and down at a frequency of MHz level, the liquid drop and the metal sheet produce a rapid relative Motion, liquid source or large particle smoke solid source enters large holes and quickly sprays out into fine particle smoke from small holes. The finer droplets are carried to the substrate of the reaction chamber by the carrier gas, and the thicker droplets are usually vibrated by the metal The cavitation field generated on the upper surface of the sheet continues to gasify, or reflux accumulates in the large hole on the back of the metal sheet, and the liquid droplets reaching a certain size continue to be ejected from the small hole by ultrasonic cavitation; the sample stage can be rotated and adjusted up and down, and the rotation speed 100-300 rpm.

The following examples include cases of a single solid source, a single liquid source, a single gas source, a combination of a solid source and a liquid source, and a combination of two solid sources, detailing the method for preparing a two-dimensional crystal material of the present invention:

Example 1

The boronene is prepared on a mica substrate by chemical vapor deposition, including the following preparation steps:

(1) Place a 0.2 mm thick mica substrate on the heating base of the reaction chamber;

(2) 1 g boron source _NaBH Powder is placed in the container of the second atomization device;

(3) Pump the air pressure of the MOCVD system to the ultimate vacuum state of 0.1 Pa, and keep it for 20 min;

(4) Set the flow rate of the carrier gas hydrogen connected to the second atomization device to 10 sccm, open the ultrasonic atomization driver in the second atomization device, and inject hydrogen into the reaction chamber;

(5) Raise the temperature of the reaction chamber to 650°C and anneal the mica for 30 min;

(6) Raise the temperature of the second atomization device to 490°C to decompose the NaBH ₄ powder to generate boron source steam, which is carried by hydrogen and refined twice by ultrasonic waves, and then reaches the reaction chamber to start the two-dimensional atomic crystal of boronene growth, keep the temperature for 60min.

Example 2

Graphene is prepared on a quartz substrate by chemical vapor deposition, including the following preparation steps:

(1) Place a 4-inch quartz substrate on the heating base of the reaction chamber;

(2) Place 100 mL of ethanol in the container of the first atomization device;

(3) Pump the air pressure of the MOCVD system to the ultimate vacuum state of 0.1 Pa, and keep it for 20 min;

(4) Feed 20 sccm of hydrogen into the reaction chamber through the gas path of the gas source to further remove the air in the system;

(5) Raise the temperature of the reaction chamber to 1000°C, and anneal the quartz substrate for 30 minutes;

(6) Set the flow rate of the carrier gas hydrogen connected to the first atomization device to 10 sccm, open the ultrasonic atomization driver in the first atomization device, inject hydrogen into the first atomization device, and be carried by hydrogen After two times of ultrasonic refinement, it reaches the reaction chamber, where the growth of graphene two-dimensional atomic crystals begins, and the temperature is maintained for 30 min.

Example 3

The boronene is prepared on a nickel substrate by chemical vapor deposition, comprising the following preparation steps:

(1) Place a 3 x 3 cm nickel foil substrate on the heating base of the reaction chamber;

(2) Pump the air pressure of the MOCVD system to the ultimate vacuum state of 0.1 Pa, and keep it for 20 min;

(3) Feed 10 sccm of hydrogen into the reaction chamber from the carrier gas inlet on the side of the second ultrasonic atomizer to further remove the air in the system;

(4) Raise the temperature of the reaction chamber to 650 °C and anneal the nickel foil substrate for 30 min;

(5) Feed 10 sccm of diborane into the reaction chamber through the gas path through the gas source, reach the reaction chamber, start the growth of the two-dimensional atomic crystal of borene, and maintain the temperature for 60 min.

Example 4

Molybdenum disulfide was prepared on a _SiO2 substrate by chemical vapor deposition, including the following preparation steps:

(1) Place the _SiO2 substrate on the heating base of the reaction chamber;

(2) Diethyl sulfide is put into the container of the first atomization device;

(3) Transition metal source Mo(CO) ₆ is put into the second atomizing device container;

(4) Pump the air pressure of the MOCVD system to the ultimate vacuum state of 0.1 Pa, and keep it for 20 min;

(5) Heat the second atomizing device at 120°C to generate steam, and mix 10 sccm of argon into the reaction chamber; simultaneously turn on the ultrasonic atomization drivers of the first and second atomizing devices, and send air to the first atomizing device 48 sccm of argon gas is passed into the middle, and the carrier gas carrier source is passed into the reaction chamber;

(6) Pass hydrogen into the reaction chamber with 10 sccm through the gas source gas path;

(7) The sample stage is heated to the growth temperature required for the crystal at 620° C. to obtain a molybdenum disulfide two-dimensional crystal material.

Example 5

Prepare indium diselenide on the _SiO2 substrate by chemical vapor deposition. In this embodiment, the first and second atomization devices are all atomization devices for solid sources as described above, including the following preparation steps:

(1) Place the _SiO2 substrate on the heating base of the reaction chamber;

(2) Pump the air pressure of the MOCVD system to the ultimate vacuum state of 0.1 Pa, and keep it for 20 min;

(3) Put the selenium powder into the first atomization device, heat to 250° C. to generate steam, mix 20 sccm of argon gas through ultrasonic refinement, and pass it into the vacuum chamber;

(4) At the same time, put indium nitrate into the second atomization device, heat to 250°C to generate steam, mix 20 sccm of argon gas and refine it by ultrasonic, and pass it into the vacuum chamber;

(5) Adjust the pressure in the vacuum chamber to 50 Pa;

(6) The sample stage is heated to start the growth of the indium diselenide two-dimensional crystal material.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still understand the foregoing embodiments The recorded technical solutions are modified, or some of the technical features are equivalently replaced. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (10)

1. An MOCVD device for preparing a two-dimensional crystal material based on ultrasonic atomization is characterized by comprising: the device comprises a gas source channel, a non-gaseous source atomization channel, an ultrasonic atomization nozzle and a reaction chamber; the outlet of the gas source channel and the outlet of the non-gaseous source atomizing channel are respectively connected with the inlet of the ultrasonic atomizing nozzle, the outlet of the ultrasonic atomizing nozzle is positioned at the top end of the inner part of the reaction chamber, and the sample stage is arranged at the position under the ultrasonic atomizing nozzle at the bottom end of the inner part of the reaction chamber.

2. The MOCVD device for preparing two-dimensional crystal materials based on ultrasonic atomization, according to claim 1, wherein the non-gaseous source atomization channel is composed of a plurality of liquid source atomization channels, solid source atomization channels or two channels.

3. The MOCVD device for preparing the two-dimensional crystal material based on the ultrasonic atomization, according to claim 2, wherein a liquid source atomization device is arranged in the liquid source atomization channel, and the liquid source atomization device comprises a container, an ultrasonic micropore atomization sheet, liquid absorption cotton and a cover; the cover is in a step shape, the bottom end of the cover is clamped at the outer side of the top end of the container, an ultrasonic micropore atomization sheet is arranged above the contact part of the cover and the container, damping rubber is arranged between the ultrasonic micropore atomization sheet and the cover, and a carrier gas inlet is arranged on the side surface of the cover above the ultrasonic micropore atomization sheet; an outlet is arranged at the top of the cover; the liquid absorption cotton is positioned in the container, the bottom of the liquid absorption cotton is positioned in the liquid source, and the top of the liquid absorption cotton is connected with the metal sheet of the through hole array on the ultrasonic micropore atomization sheet; and a liquid source is transmitted to the metal sheet of the through hole array in the ultrasonic micropore atomization sheet through the liquid absorption cotton, and is atomized to smaller particles and even vaporized under the drive of piezoelectric ceramics.

4. The MOCVD apparatus for preparing two-dimensional crystal material based on ultrasonic atomization as claimed in claim 2, wherein a solid source atomization device is arranged in the solid source atomization channel, and the solid source atomization device comprises a container, a high-ultrasonic-resistance micropore atomization sheet and a cover; the cover is in a step shape, the bottom end of the cover is clamped at the outer side of the top end of the container, a high-temperature-resistant ultrasonic micropore atomization sheet is arranged above the contact part of the cover and the container, a high-temperature-resistant damping block is arranged between the high-temperature-resistant ultrasonic micropore atomization sheet and the cover, and a carrier gas inlet is arranged on the side surface of the cover above the high-temperature-resistant ultrasonic micropore atomization sheet; an outlet is arranged at the top of the cover; the bottom of the container is provided with a heating base, the solid source is placed on the heating base, the solid source is evaporated to a metal sheet of a through hole array in the high-temperature-resistant driver through heating, and the solid source is further atomized to smaller particles and even vaporized under the driving of piezoelectric ceramics.

5. The MOCVD device for preparing the two-dimensional crystal material based on the ultrasonic atomization, according to claim 1, wherein the ultrasonic atomization nozzle comprises a gas mixing chamber, a high-temperature resistant ultrasonic micropore atomization sheet and a frustum-shaped shield; the top of gas mixing chamber sets up a plurality of air inlets for connect gaseous state source passageway and non-gaseous state source atomizing passageway export, the bottom is to the both sides outstanding high temperature resistant supersound micropore atomizing piece of installation, high temperature resistant supersound micropore atomizing piece and mix install high temperature resistant snubber block between the gas mixing chamber inner wall, the gas mixing chamber bottom is located high temperature resistant supersound micropore atomizing piece below and sets up frustum shape guard shield.

6. The MOCVD device for preparing the two-dimensional crystal material based on the ultrasonic atomization as recited in claim 3, 4 or 5, wherein the ultrasonic micropore atomization sheet is composed of high temperature resistant annular piezoelectric ceramics and a metal sheet with a conical hole, a liquid inlet is formed at one end of a large hole of the conical hole, a gas outlet is formed at one end of a small hole of the conical hole, and the annular piezoelectric ceramics is attached to one surface of a large hole of the metal sheet.

7. The MOCVD apparatus for preparing two-dimensional crystal material based on ultrasonic atomization, according to claim 6, wherein the aperture of the big hole at one end is 5-20 μm, and the aperture of the small hole at one end is 1-5 μm.

8. The MOCVD apparatus for preparing two-dimensional crystal material based on ultrasonic atomization as recited in claim 6, wherein a vertical distance between one end of the small hole of the ultrasonic micropore atomization sheet in the ultrasonic atomization nozzle and the sample stage is 5-100 mm.

9. The MOCVD apparatus for preparing two-dimensional crystal material based on ultrasonic atomization, according to claim 1 or 8, wherein the sample stage is rotatable and adjustable up and down.

10. A method for producing a two-dimensional crystalline material using the apparatus of any one of claims 1 to 9, comprising the steps of:

(1) Placing the substrate on a reaction chamber sample stage;

(2) Pumping the gas pressure of the MOCVD device to a limit vacuum state and keeping the gas pressure for 20 min;

(3) Introducing carrier gas into the reaction chamber to further remove air in the system;

(4) Adjusting the temperature and the pressure of the reaction chamber to the temperature and the pressure required by the reaction, and annealing the substrate;

(5) And opening a carrier gas inlet, opening an atomizing device, injecting the refined source material gas into the reaction chamber through the carrier gas, and starting the growth of the two-dimensional crystal material.

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