CN107287653B - Cadmium iodide two-dimensional material and preparation method thereof - Google Patents

Cadmium iodide two-dimensional material and preparation method thereof Download PDF

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CN107287653B
CN107287653B CN201710456549.5A CN201710456549A CN107287653B CN 107287653 B CN107287653 B CN 107287653B CN 201710456549 A CN201710456549 A CN 201710456549A CN 107287653 B CN107287653 B CN 107287653B
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cadmium iodide
substrate
heterojunction
nanosheet
cadmium
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CN107287653A (en
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段曦东
段镶锋
艾若奇
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Hunan University
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    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B23/00—Single-crystal growth by condensing evaporated or sublimed materials
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y40/00—Manufacture or treatment of nanostructures
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    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
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    • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
    • C23C14/06—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the coating material
    • C23C14/0694—Halides
    • C—CHEMISTRY; METALLURGY
    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B29/00—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
    • C30B29/10—Inorganic compounds or compositions
    • C30B29/12—Halides
    • C—CHEMISTRY; METALLURGY
    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B29/00—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
    • C30B29/60—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape characterised by shape
    • C30B29/64—Flat crystals, e.g. plates, strips or discs

Abstract

The invention discloses a cadmium iodide two-dimensional material which is a cadmium iodide nanosheet; or a cadmium iodide nanosheet-based vertical heterojunction; or a cadmium iodide heterojunction array. In addition, the invention also discloses a preparation method of the cadmium iodide two-dimensional material, namely, the cadmium iodide powder is physically deposited on the surface of the substrate in a gas phase manner at the temperature of 320-350 ℃ and the carrier gas flow of 120-150sccm to prepare cadmium iodide nano-sheets; or physical vapor deposition is carried out on the surface of the substrate on which the two-dimensional material A grows, so as to prepare the vertical heterojunction cadmium iodide-two-dimensional material A. The cadmium iodide nanosheet and the heterojunction thereof expand a new two-dimensional material and a two-dimensional heterojunction thereof, and the arrayed growth thereof provides new possibility for finding new excellent electronic devices and equipment. The preparation process of the invention has no complex operation steps and other raw materials, and the equipment is simple.

Description

Cadmium iodide two-dimensional material and preparation method thereof
Technical Field
The invention belongs to the field of nano materials, and relates to a two-dimensional cadmium iodide nanosheet, a vertical heterojunction based on the cadmium iodide nanosheet and a preparation method of a vertical heterojunction array thereof
Technical Field
Cadmium iodide is a layered material.
The discovery of graphene has triggered the research heat of science to two-dimensional materials, however, graphene has been greatly limited in the fields of electronics and optoelectronics because of its band structure presenting zero band gap. In a single layer of MoS2The two-dimensional transition metal dichalcogenides (2D-TMDs) as representative have attracted considerable interest due to the non-zero band gap. In recent years, many reports on the preparation, property research and application of 2D-TMDs have appeared. Recently, such different new two-dimensional materials, such as group IIIA-VIA two-dimensional materials and group IVA-VIIA two-dimensional materials, have been actively explored. Cadmium iodide as a layered material expands a two-dimensional material family, and a vertical heterojunction connection array thereof provide new possibilities for new excellent electronic devices and equipment.
Based on the unique two-dimensional structure, the two-dimensional cadmium iodide and the two-dimensional structure based on the two-dimensional cadmium iodide have huge potential. Although the cadmium iodide nanosheet has such great potential, currently, the preparation of the cadmium iodide nanosheet with different thicknesses, good crystallinity and good appearance is still to be researched.
Existing methods of preparation such as thermal vapor deposition,[1][2]the prepared cadmium iodide film has the technical problems of nonuniform film thickness, nonuniform appearance, poor crystallinity, poor appearance and the like in the existing preparation method. The preparation method of the heterojunction is complicated,[3][4]especially the preparation of arrayed heterojunctions is still worth studying.
Reference to the literature
[1]Kariper，I.A.Structural，optical and porosity properties of CdI2thin film.J.Mater.Res.Technol.2016，5，77-83.
[2]Tyagi，P.；Vedeshwar，A.；Mehra，N.Thickness dependent optical properties of CdI2 films.Physica B 2001，304，166-174.
[3]Yu，W.J.；Liu，Y.；Zhou，H.；Yin，A.；Li，Z.；Huang，Y.；Duan，X.Highly efficient gate-tunable photocurrent generation in vertical heterostructuresof layered materials.Nat.Nanotech.2013，8，952-958.
[4]Yu，J.H.；Lee，H.R.；Hong，S.S.；Kong，D.；Lee，H.-W.；Wang，H.；Xiong，F.；Wang，S.；Cui，Y.Vertical heterostructure of two-dimensional MoS2 and WSe2 with vertically aligned layers.Nano Lett.2015，15，1031-1035.
Disclosure of Invention
The invention provides a preparation method of a cadmium iodide two-dimensional material, which aims to solve the technical problems of thick prepared cadmium iodide, nonuniform appearance, poor crystallinity, poor appearance and the like in the conventional preparation method.
The second purpose of the invention is to provide a cadmium iodide two-dimensional material prepared by the preparation method, which specifically comprises the prepared cadmium iodide nanosheet and the prepared cadmium iodide heterojunction.
A cadmium iodide two-dimensional material is a cadmium iodide nanosheet; or a cadmium iodide nanosheet-based vertical heterojunction; or a cadmium iodide heterojunction array.
A cadmium iodide two-dimensional material is a cadmium iodide nanosheet or is based on a cadmium iodide nanosheet vertical heterojunction (the two-dimensional material A-cadmium iodide heterojunction is also called as a cadmium iodide heterojunction for short in the invention), and the cadmium iodide nanosheet vertical heterojunction is obtained by depositing cadmium iodide on the surface of the two-dimensional material A. The cadmium iodide heterojunction array belongs to the category of a cadmium iodide nanosheet-based vertical heterojunction, and is a cadmium iodide nanosheet-based vertical heterojunction with an array structure formed by depositing cadmium iodide on the surface of a two-dimensional material with a certain array pattern.
The cadmium iodide nanosheet is a flaky nano-sized material.
The optimized cadmium iodide nanosheet is of a single-crystal structure.
Preferably, the thickness of the cadmium iodide nanosheet is 5-22 nm.
The two-dimensional material A-cadmium iodide heterojunction is a vertical heterojunction formed by vertically depositing cadmium iodide on the surface of a two-dimensional material A nanosheet. The two-dimensional material A is MoS2、WSe2Or WS2。
The preferred heterojunction of the invention is a vertical heterojunction CdI2/MoS2、CdI2/WSe2Or CdI2/WS2。
The cadmium iodide heterojunction array can etch an array pattern on the surface of a two-dimensional material A, and then deposit cadmium iodide to obtain a two-dimensional material A-cadmium iodide heterojunction with a special array appearance (also called as a vertical heterojunction array).
The preparation method of the cadmium iodide two-dimensional material comprises the steps of carrying out physical vapor deposition on cadmium iodide powder on the surface of a substrate at the temperature of 320-350 ℃ and the carrier gas flow of 120-150sccm to prepare cadmium iodide nanosheets; or physical vapor deposition is carried out on the surface of the substrate on which the two-dimensional material A grows, so as to prepare the vertical heterojunction cadmium iodide-two-dimensional material A.
In the invention, cadmium iodide is evaporated in a physical gas phase, and is deposited on the surface of a substrate in a low-temperature region under the action of carrier gas, and cadmium iodide nanosheets with different thicknesses, good crystallinity and uniform appearance are obtained by regulating and controlling the temperature and the carrier gas flow, wherein the minimum thickness can reach 5 nm.
In the invention, through the selection of the substrate in vapor deposition, the preparation method can be adopted to prepare the nano sheet material or the heterojunction material.
The inventor finds that when the cadmium iodide nanosheet is prepared, under the appropriate growth temperature and carrier gas flow, the morphology of the prepared cadmium iodide nanosheet is improved, the thickness of the prepared nanosheet is controlled, the crystallization performance of the material is improved, and the like.
The preparation method of the cadmium iodide nanosheet provided by the invention is characterized in that cadmium iodide powder is deposited on the surface of a substrate in a gas phase manner at the temperature of 320-350 ℃ and the carrier gas flow rate of 120-150sccm, so that the cadmium iodide nanosheet is formed on the surface of the substrate.
Preferably, in the preparation process of the cadmium iodide nanosheet, the growth temperature of cadmium iodide is controlled to be 320-335 ℃ and 120-135 sccm.
The method can prepare cadmium iodide nanosheets with different thicknesses, and the prepared cadmium iodide nanosheets are 5-22nm thick, are single crystals, and are good in crystallinity and morphology. The method can also be used for simply preparing the cadmium iodide vertical heterojunction and the vertical heterojunction array. The method has simple operation process and good repeatability.
Preferably, in the preparation process of the cadmium iodide nanosheet, the substrate is Si/SiO2Substrates, sapphire substrates, mica substrates, and the like.
Further preferably, in the preparation process of the cadmium iodide nanosheet, the substrate is Si/300nmSiO2A substrate.
Preferably, the vapor deposition is carried out in a tubular vapor deposition furnace, wherein the substrate is placed downstream of the cadmium iodide powder.
At the temperature, the cadmium iodide powder is gasified and then carried and deposited on the surface of the substrate positioned at the downstream of the carrier gas flow under the cooperation of the carrier gas flow, and the cadmium iodide nanosheet is formed on the surface of the substrate.
Preferably, in the preparation process of the cadmium iodide nanosheet, the carrier gas is argon and/or nitrogen; further preferred is argon gas.
Preferably, the vapor deposition time of the preparation process of the cadmium iodide nanosheet is 20-30 min.
According to the method, the substrate deposited with the two-dimensional material A is replaced, and the cadmium iodide is deposited on the surface of the two-dimensional material A under the same conditions (mainly including growth temperature and carrier gas flow) as the cadmium iodide nanosheets, so that the cadmium iodide vertical heterojunction is obtained.
The invention prepares the vertical heterojunction (cadmium iodide heterojunction) by compounding MoS on the substrate2、WS2、WSe2Vapor deposition of cadmium iodide on the surface of at least one two-dimensional material to form said matrixIn the vertical heterojunction of cadmium iodide.
Preferably, the heterojunction has MoS on the substrate2、WS2、WSe2And (3) carrying out vapor deposition on the surface of at least one nano sheet to form the cadmium iodide heterojunction.
The cadmium iodide and the following MoS2The nanosheets interact with van der waals forces to form a vertical heterojunction.
In the invention, MoS is firstly deposited on the surface of a substrate2、WS2、WSe2And at least one nano sheet, and then vapor-depositing the cadmium iodide on the surface of the composite nano sheet to obtain the cadmium iodide heterojunction.
Preferably, the cadmium iodide heterojunction is formed by compounding MoS on a substrate2、WS2、WSe2And (3) carrying out vapor deposition on the surface of at least one nano sheet to form the cadmium iodide heterojunction.
The invention provides a preparation method based on a cadmium iodide nanosheet vertical heterojunction, wherein MoS is formed by vapor deposition of cadmium iodide powder on a substrate2、WS2、WSe2Preparing the cadmium iodide heterojunction on the surface of at least one nanosheet; the temperature of vapor deposition is 320-350 ℃, and the flow rate of carrier gas is 120-150 sccm.
Preferably, in the preparation process of the cadmium iodide nanosheet-based vertical heterojunction, the substrate is Si/SiO2Substrates, sapphire substrates, mica substrates, and the like; further preferably Si/300nmSiO2A substrate.
In the preparation process of the cadmium iodide nanosheet-based vertical heterojunction, MoS is compounded on the surface of a substrate2、WS2、WSe2At least one nanoplatelet; the composite method can be selected from commonly available physical (chemical) vapor deposition methods.
In the preparation process of the cadmium iodide heterojunction, vapor deposition is carried out in a tubular vapor deposition furnace, wherein the substrate is arranged at the downstream of carrier gas flow of cadmium iodide powder.
In the preparation process of the cadmium iodide heterojunction, the carrier gas is argon and/or nitrogen; argon is preferred.
In the preparation process of the cadmium iodide heterojunction, the vapor deposition time is 20-30 min.
In the invention, cadmium iodide is deposited on the pattern surface of the two-dimensional material A by replacing the substrate with the two-dimensional material A with an array pattern under the growth temperature and the carrier gas flow of the invention, and the cadmium iodide heterojunction array is prepared. Preferably, the cadmium iodide is grown and deposited on the substrate with MoS2、WS2、WSe2At least one nanosheet array pattern, cadmium iodide selectively growing on the nanosheet array pattern to form said cadmium iodide vertical heterojunction array (cadmium iodide heterojunction array).
The preparation method of the cadmium iodide heterojunction array provided by the invention comprises the step of arranging MoS on the substrate2、WS2、WSe2Etching the surface of at least one nano sheet to obtain a pattern surface with an array, and then depositing cadmium iodide powder on the pattern in a gas phase manner at the temperature of 320-350 ℃ and the carrier gas flow of 120-150sccm to obtain the cadmium iodide heterojunction array.
In the preparation method of the cadmium iodide heterojunction array, MoS is compounded on the substrate2、WS2、WSe2And etching the surface of at least one nano sheet by oxygen plasma to obtain the pattern surface.
In the preparation method of the cadmium iodide heterojunction array, MoS is arranged on the substrate2、WS2、WSe2And coating a poly electron beam exposure resist on the surface of at least one nano sheet, then carrying out annealing treatment and electron beam exposure preparation, cleaning, and then carrying out oxygen plasma treatment to obtain the pattern surface.
The poly electron beam exposure resist is at least one of methyl methacrylate (PMMA), HSQ, SU8 and UV 3.
Further preferably, the poly electron beam exposure resist is methyl methacrylate (PMMA).
The cadmium iodide heterojunction arrayThe substrate is Si/SiO2Substrates, sapphire substrates, mica substrates, and the like; further preferably Si/300nmSiO2A substrate.
In the preparation process of the cadmium iodide heterojunction array, the preferable nano material A is WS2。
Patterned WS for use in preparation of cadmium iodide nanosheet vertical heterojunction arrays2The array preparation method of (1) is as follows: in the long existence of WS2Nanosheet Si/300nmSiO2Spin coating PMMA, annealing, exposing with electron beam according to certain pattern, performing oxygen plasma etching, cleaning with acetone and ethanol, and finally obtaining patterned WS2The nanosheet array of (a).
In the preparation process of the cadmium iodide heterojunction array, vapor deposition is carried out in a tubular vapor deposition furnace, wherein the substrate is placed at the downstream of cadmium iodide powder.
In the preparation process of the cadmium iodide heterojunction array, the carrier gas is argon and/or nitrogen; argon is preferred.
In the preparation process of the cadmium iodide heterojunction array, the vapor deposition time is 20-30 min.
The technical scheme of the invention has the same invention point, namely: and depositing cadmium iodide powder serving as a raw material on a substrate or the surface compounded with the nano material by adopting a physical vapor deposition method to form a corresponding nano sheet, a heterojunction and a heterojunction array.
Other two-dimensional materials (such as transition metal disulfide compound nanosheets) or two-dimensional material arrays are used as growth substrates in the preparation of the vertical heterojunction and the vertical heterojunction array based on the cadmium iodide nanosheets.
The invention adopts a physical vapor deposition method, uses cadmium iodide powder as a raw material, and adopts Si/300nmSiO2As a substrate, preparing cadmium iodide nanosheets, heterojunction and heterojunction arrays in an argon atmosphere at a constant temperature for a certain time in a tubular atmosphere furnace; the temperature of the cadmium iodide nano-sheet in the growth process (vapor deposition) is 320-350 ℃, and the temperature is constantThe time is 20-30min, and the flow of argon carrier gas is 120-150 sccm.
One preferred scheme is to use a grown MoS2、WS2、WSe2Nanosheet Si/300nmSiO2Then, under the growth temperature of cadmium iodide and the carrier gas flow (320-350 ℃; 120-2、WS2、WSe2Nucleation and growth on the nanoplatelets to form CdI2/MoS2(WS2、WSe2) A vertical heterojunction.
In a preferred embodiment, a method for forming a cadmium iodide vertical heterojunction uses patterned WS2Of nanosheet array of Si/300nmSiO2Then, under the growth temperature of cadmium iodide and the carrier gas flow (320-350 ℃; 120-2Nucleation and growth on the nanoplatelets to form CdI2/WS2A vertical heterojunction array. The method comprises the following specific steps: placing cadmium iodide powder in a tubular atmosphere furnace, placing the furnace in a constant temperature region (320 ℃) of the furnace, and using Si/300nmSiO2The silicon oxide wafer is used as a growth substrate of the nano-sheet and is placed in a temperature change zone at the downstream of a furnace to obtain a proper crystal growth temperature. Argon is used as carrier gas, the flow of the argon is regulated, and the cadmium iodide nanosheet with the thickness of 5-220nm can be obtained after constant temperature for a certain time. The growth of the heterojunction adopts the growth of MoS2、WS2、WSe2Nanosheet Si/300nmSiO2As a substrate, CdI is prepared under appropriate conditions2/MoS2(WS2、WSe2) A vertical heterojunction. To WS2The substrate is subjected to graphic array treatment to be used as a growth substrate, and the vertical heterojunction array can be prepared.
The cadmium iodide nanosheet and the heterojunction thereof expand a new two-dimensional material and a two-dimensional heterojunction thereof, and the arrayed growth thereof provides new possibility for finding new excellent electronic devices and equipment.
Advantageous effects
The preparation process of the invention has no complex operation steps and other raw materials, and the equipment is simple.
The method can prepare cadmium iodide nanosheets with different thicknesses, and the prepared cadmium iodide nanosheets are 5-22nm thick, are single crystals, and are good in crystallinity and morphology. The method can also be used for simply preparing the cadmium iodide vertical heterojunction and the vertical heterojunction array.
Drawings
FIG. 1 is a schematic view of an apparatus for preparing a cadmium iodide two-dimensional material;
FIG. 2 is an optical photograph of cadmium iodide prepared in example 1;
FIG. 3 is an optical photograph of cadmium iodide prepared in example 2;
FIG. 4 is an optical photograph of cadmium iodide prepared in example 3;
FIG. 5 preparation of CdI in example 42/MoS2Vertical heterojunction optical photographs;
FIG. 6 preparation of CdI in example 52/WS2Vertical heterojunction optical photographs;
FIG. 7 is a schematic representation of the preparation of CdI in example 62/WSe2Vertical heterojunction optical photographs;
FIG. 8 preparation of CdI in example 72/WS2Vertical heterojunction array optical photographs and raman imaging thereof;
FIG. 9 is an optical photograph of cadmium iodide prepared in example 8;
fig. 10 is an optical photograph of cadmium iodide prepared in comparative example 1;
fig. 11 is an optical photograph of cadmium iodide prepared in comparative example 2.
The specific implementation method comprises the following steps:
in order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be further clearly and completely described below with reference to the embodiments of the present invention. It should be noted that the present invention is not limited to the following.
Example 1
The specific preparation process of the embodiment comprises the following steps: preparing cadmium iodide nanosheets: 0.1g of cadmium iodide powder was weighed into a porcelain boat, which was placed in the thermostatic zone of the furnace, and a small piece of Si/300nmSiO2The silicon oxide wafer is used as a growth substrate of the nano-sheet and is placed in anotherA porcelain boat is placed in the temperature-varying zone downstream of the furnace to obtain the proper crystal growth temperature. The furnace was first purged with argon to remove oxygen and water vapor. And then raising the temperature to 320 ℃, adjusting the argon flow to 120sccm, keeping the temperature for 20min, and generating the single crystal cadmium iodide nanosheets at certain positions of the silicon wafer. The prepared cadmium iodide nanosheet optical photo is shown in fig. 2.
FIG. 2 is an optical schematic diagram of a prepared cadmium iodide nanosheet, Si/SiO2The color of the substrate is purple, and the color of the cadmium iodide nanosheet is mostly blue and the minority is yellow. As can be clearly seen from the figure, most of the obtained cadmium iodide nanosheets present regular hexagonal and triangular morphologies. The blue nano-sheet is thin, the thickness of the blue nano-sheet is 5nm, the thickness of other nano-sheets is 8-30nm, and the size of the other nano-sheets is 2-10 mu m. The scale in FIG. 2 is 10 μm.
Example 2
The specific preparation process of the embodiment comprises the following steps: preparing cadmium iodide nanosheets: 0.1g of cadmium iodide powder was weighed into a porcelain boat, which was placed in the thermostatic zone of the furnace, and a small piece of Si/300nmSiO2The silicon oxide wafer is used as a growth substrate of the nano-sheet, is placed in another porcelain boat, and is placed in a temperature changing zone at the downstream of a furnace to obtain a proper crystal growth temperature. The furnace was first purged with argon to remove oxygen and water vapor. And then raising the temperature to 335 ℃, adjusting the argon flow to be 135sccm, keeping the temperature for 20min, and generating the single crystal cadmium iodide nanosheets at certain positions of the silicon wafer. The photo of the prepared cadmium iodide nanosheet is shown in fig. 3.
FIG. 3 is an optical schematic of a cadmium iodide nanosheet prepared, Si/SiO2The color of the substrate is blue purple, and the color of the cadmium iodide nanosheet is mostly yellow and is rarely blue, orange, red and green. As can be clearly seen from the figure, most of the obtained cadmium iodide nanosheets present regular hexagonal and triangular morphologies. The blue nano-sheet is thin, the thickness of the blue nano-sheet is 20nm, the thickness of other nano-sheets is 40-220nm, and the size of the blue nano-sheet is 2-10 μm. The scale in FIG. 3 is 10 μm.
Example 3
The specific preparation process of the embodiment comprises the following steps: preparing cadmium iodide nanosheets: 0.1g of cadmium iodide powder was weighed into a porcelain boat, which was placed in the thermostatic zone of the furnace, and a small piece of Si/300nmSiO2The silicon oxide wafer is used as a growth substrate of the nano-sheet, is placed in another porcelain boat, and is placed in a temperature changing zone at the downstream of a furnace to obtain a proper crystal growth temperature. The furnace was first purged with argon to remove oxygen and water vapor. And then raising the temperature to 350 ℃, adjusting the argon flow to be 150sccm, keeping the temperature for 20min, and generating the single crystal cadmium iodide nanosheets at certain positions of the silicon wafer. The photo of the prepared cadmium iodide nanosheet is shown in fig. 4.
FIG. 4 is an optical schematic of a cadmium iodide nanosheet prepared, Si/SiO2The color of the substrate is purple, the color of the cadmium iodide nanosheet is mostly red, and the color of the cadmium iodide nanosheet is a few of yellow, orange and green. As can be clearly seen from the figure, most of the obtained cadmium iodide nanosheets present regular hexagonal and triangular morphologies. The yellow nano-sheet is thinner, the thickness of the yellow nano-sheet is about 70nm, the thickness of other nano-sheets is 120-220mm, and the size is uniform and is 2-10 μm. The scale in FIG. 4 is 10 μm.
Example 4
CdI2/MoS2Preparing a vertical heterojunction: 0.1g of cadmium iodide powder was weighed into a porcelain boat, which was placed in a constant temperature area of a furnace, and a small piece of powder having MoS thereon was put2Nanosheet Si/300nmSiO2The silicon oxide wafer is used as a growth substrate of the nano-sheet, is placed in another porcelain boat, and is placed in a temperature changing zone at the downstream of a furnace to obtain a proper crystal growth temperature. The furnace was first purged with argon to remove oxygen and water vapor. Then raising the temperature to 325 ℃, adjusting the argon flow to 128sccm, keeping the temperature for 25min, and selectively setting the cadmium iodide nanosheet to be MoS2Growth on nanoplates to form CdI2/MoS2A heterojunction is generated.
FIG. 5 is a process for preparing CdI2/MoS2Vertical heterojunction optical photo, Si/SiO2The base color is purple, the lower triangle MoS2The color is dark purple, and the triangular cadmium iodide on the upper side is yellow. From the figureClearly visible is the MoS in which cadmium iodide nanosheets can be selectively grown2The cadmium iodide is completely covered on the MoS of the bottom layer2Surface, CdI obtained2/MoS2The vertical heterojunction has better appearance.
Example 5
CdI2/WS2Preparing a vertical heterojunction: 0.1g of cadmium iodide powder was weighed into a porcelain boat, which was placed in a constant temperature area of a furnace, and a small piece of material having a length of WS2Nanosheet Si/300nmSiO2The silicon oxide wafer is used as a growth substrate of the nano-sheet, is placed in another porcelain boat, and is placed in a temperature changing zone at the downstream of a furnace to obtain a proper crystal growth temperature. The furnace was first purged with argon to remove oxygen and water vapor. Then raising the temperature to 350 ℃, adjusting the argon flow to 125SCCM, keeping the temperature for 20min, and selectively placing the cadmium iodide nanosheet in WS2Growth on nanoplates to form CdI2/WS2A heterojunction is generated.
FIG. 6 is a process for preparing CdI2/WS2Vertical heterojunction optical photo, Si/SiO2The color of the substrate is purple, the lower WS2Blue, the hexagonal cadmium iodide above is yellow. From the figure, it can be clearly seen that cadmium iodide nanosheets can selectively grow on WS2The cadmium iodide is completely grown on the WS at the bottom layer2Surface, CdI obtained2/WS2The vertical heterojunction has better appearance.
Example 6
CdI2/WSe2Preparing a vertical heterojunction: 0.1g of cadmium iodide powder was weighed into a porcelain boat, which was placed in a constant temperature area of a furnace, and a small piece having WSe grown thereon was placed2Nanosheet Si/300nmSiO2The silicon oxide wafer is used as a growth substrate of the nano-sheet, is placed in another porcelain boat, and is placed in a temperature changing zone at the downstream of a furnace to obtain a proper crystal growth temperature. The furnace was first purged with argon to remove oxygen and water vapor. Then raising the temperature to 330 ℃, adjusting the argon flow to 140SCCM, keeping the temperature for 20min, and selectively placing the cadmium iodide nanosheet in the WSe2On the nano-chipGrow to form CdI2/WSe2A heterojunction is generated.
FIG. 7 is a process for preparing CdI2/WSe2Vertical heterojunction optical photo, Si/SiO2The substrate was purple in color, WSe below2Blue, the hexagonal cadmium iodide above is green. As can be clearly seen from the figure, the WSe in which cadmium iodide nanosheets can be selectively grown2The WSe growing on the bottom layer is completely covered by the cadmium iodide2Surface, CdI obtained2/WSe2The vertical heterojunction has better appearance.
Example 7
CdI2/WS2And (3) preparing a vertical heterojunction array.
WS2Preparation of the nanosheet array: WS2Nanosheet Si/300nmSiO2Spin coating PMMA, annealing, exposing with electron beam according to certain pattern, performing oxygen plasma etching, cleaning with acetone and ethanol, and finally or obtaining patterned WS2An array of (1).
0.1g of cadmium iodide powder was weighed into a porcelain boat, which was placed in a constant temperature area of a furnace, and a small piece of patterned WS was grown2Arrays of nanosheets WS2Si/300nmSiO2The silicon oxide wafer is used as a growth substrate of the nano-sheet, is placed in another porcelain boat, and is placed in a temperature changing zone at the downstream of a furnace to obtain a proper crystal growth temperature. The furnace was first purged with argon to remove oxygen and water vapor. Then raising the temperature to 330 ℃, adjusting the argon flow to 140SCCM, keeping the temperature for 20min, and selectively placing the cadmium iodide nanosheet in WS2Growth on nanoplates to form CdI2/WS2A heterojunction array.
FIG. 8 is a process for preparing CdI2/WS2Vertical heterojunction array optical photographs and raman imaging thereof.
In FIG. 8, a) arrayed WS2Photo of nanosheets, Si/SiO2The color of the substrate is light purple, WS2The nanosheet array is purple; b) is CdI2-WS2Optical pictures of heterojunction arrays, Si/SiO2The color of the substrate is light purple, CdI2The nano-sheet is green and red, CdI2The nano-sheet presents regular hexagonal morphology, CdI2The nanosheet completely covers WS2Growing on the nanosheet array; c, d) are each 110cm-1And 348cm-1CdI of (C)2-WS2Raman signal imaging of the heterojunction array, all scales in fig. 8 are 5 μm.
Example 8
The specific preparation process of the embodiment comprises the following steps: preparing cadmium iodide nanosheets: 0.1g of cadmium iodide powder was weighed into a porcelain boat, which was placed in the thermostatic zone of the furnace, and a small piece of Si/300nmSiO2The silicon oxide wafer is used as a growth substrate of the nano-sheet, is placed in another porcelain boat, and is placed in a temperature changing zone at the downstream of a furnace to obtain a proper crystal growth temperature. The furnace was first purged with argon to remove oxygen and water vapor. And then raising the temperature to 350 ℃, adjusting the flow of argon to 125SCCM, keeping the temperature for 20min, and generating the single crystal cadmium iodide nanosheet at a certain silicon wafer position. The prepared cadmium iodide nanosheet optical photo is shown in fig. 9.
The optical schematic diagram of the prepared cadmium iodide nanosheet shows that the cadmium iodide nanosheet has two shapes of a triangular hexagon, different colors and different thicknesses, and the scale is 10 microns.
Comparative example 1
The specific preparation process of comparative example 1 of this embodiment comprises the following steps: preparing cadmium iodide nanosheets: 0.1g of cadmium iodide powder was weighed into a porcelain boat, which was placed in the thermostatic zone of the furnace, and a small piece of Si/300nmSiO2The silicon oxide wafer is used as a growth substrate of the nano-sheet, is placed in another porcelain boat, and is placed in a temperature changing zone at the downstream of a furnace to obtain a proper crystal growth temperature. The furnace was first purged with argon to remove oxygen and water vapor. Then the temperature is raised to 300 ℃, the argon flow is regulated to be 100sccm, the temperature is kept for 20min, and cadmium iodide on the silicon wafer is not formed. The prepared cadmium iodide nanosheet optical photo is shown in fig. 10.
FIG. 10 is an optical schematic of cadmium iodide nanosheets prepared, Si/SiO2The color of the substrate is purple, and cadmium iodide is nanoThe color of the tablet is mostly yellow, and the few are orange, red and blue. As can be seen from the figure, most of the obtained products are not formed. The scale in FIG. 9 is 10 μm.
Comparative example 2
The specific preparation process of comparative example 2 of this embodiment comprises the following steps: preparing cadmium iodide nanosheets: 0.1g of cadmium iodide powder was weighed into a porcelain boat, which was placed in the thermostatic zone of the furnace, and a small piece of Si/300nmSiO2The silicon oxide wafer is used as a growth substrate of the nano-sheet, is placed in another porcelain boat, and is placed in a temperature changing zone at the downstream of a furnace to obtain a proper crystal growth temperature. The furnace was first purged with argon to remove oxygen and water vapor. Then the temperature is raised to 400 ℃, the argon flow is regulated to be 200sccm, the temperature is kept for 20min, and cadmium iodide on the silicon wafer is not formed. The photo of the prepared cadmium iodide nanosheet is shown in fig. 11.
FIG. 11 is an optical schematic of cadmium iodide nanosheets prepared, Si/SiO2The color of the substrate is purple, and the color of the cadmium iodide nanosheet is mostly uneven yellow and green. As can be seen from the figure, the cadmium iodide nanosheet is irregular in shape and quite thick. The scale in FIG. 11 is 10 μm.
The research results of the embodiments 1 to 3 and 8 and the comparative examples 1 to 2 show that the cadmium iodide nanosheets with excellent performance are difficult to prepare under the parameters of the growth temperature and the like of the invention.

Claims (5)

1. A preparation method of cadmium iodide nanosheets is characterized in that cadmium iodide powder is deposited on the surface of a substrate in a gas phase manner at the temperature of 320-350 ℃ and the carrier gas flow rate of 120-150sccm, and cadmium iodide nanosheets are formed on the surface of the substrate;
the cadmium iodide nanosheet is of a single-crystal structure; the thickness of the cadmium iodide nanosheet is 5-22 nm;
the shape of the cadmium iodide nanosheet is triangular or hexagonal.
2. A process for preparing cadmium iodide nanoplates as in claim 1 wherein the substrate is Si/SiO2A substrate, a sapphire substrate or a mica substrate,
the vapor deposition is carried out in a tubular vapor deposition furnace, wherein the substrate is placed downstream of the cadmium iodide powder;
the carrier gas is argon and/or nitrogen;
the vapor deposition time is 20-30 min.
3. A preparation method of a vertical heterojunction based on cadmium iodide nanosheets is characterized in that the vertical heterojunction based on cadmium iodide nanosheets is: composite with MoS on the substrate2、WS2、WSe2Carrying out vapor deposition on the surface of at least one two-dimensional material to form the cadmium iodide nanosheet-based vertical heterojunction;
the preparation process comprises the following steps: vapor deposition of cadmium iodide powder on a substrate with MoS2、WS2、WSe2At least one nano-sheet surface to prepare the cadmium iodide nano-sheet-based vertical heterojunction; the temperature of vapor deposition is 320-350 ℃, and the flow rate of carrier gas is 120-150 sccm.
4. Method for the preparation of vertical heterojunctions based on cadmium iodide nanoplates as claimed in claim 3, characterized in that the time of vapour deposition is 20-30 min.
5. A preparation method of a cadmium iodide heterojunction array is characterized in that the cadmium iodide heterojunction array is as follows: the cadmium iodide is grown and deposited on the substrate and provided with MoS2、WS2、WSe2At least one nanosheet array pattern, cadmium iodide selectively growing on the nanosheet array pattern to form said cadmium iodide heterojunction array:
the preparation process comprises the following steps: having MoS on the substrate2、WS2、WSe2Etching the surface of at least one nano sheet to obtain a pattern surface with an array, and depositing cadmium iodide powder on the pattern in a gas phase manner at the temperature of 320-350 ℃ and the carrier gas flow of 120-150sccm to obtain the cadmium iodide heterojunction array;
wherein, atThe substrate has MoS2、WS2、WSe2Coating a poly electron beam exposure resist on the surface of at least one nano sheet, then carrying out annealing treatment and electron beam exposure to prepare a pattern, cleaning, and then carrying out oxygen plasma treatment to prepare the pattern surface;
the poly electron beam exposure resist is at least one of methyl methacrylate, HSQ, SU8 and UV 3;
the vapor deposition time is 20-30 min.
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Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
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Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103579419A (en) * 2013-11-13 2014-02-12 苏州科技学院 Grapheme/MoS2/Si heterojunction thin-film solar cell and manufacturing method thereof

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
Band gap engineering of a soft inorganic compound PbI2 by incommensurate van der Waals epitaxy;Yiping Wang等;《APPLIED PHYSICS LETTERS》;20160105;第108卷;013105 *
Long-term evolution of luminescent properties in CdI2 crystals;I.Karbovnyk等;《I.Karbovnyk等》;20160731;第42卷(第7期);594-596 *
Thickness dependent optical properties of CdI2 films;Pankaj Tyagi等;《Physica B》;20011231;第304卷;166-174 *

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