Apparatus for positioning and method for preparing inas nanowire array

Abstract

The application relates to a device and a preparation method for positioning InAs nanowire arrays, which combines controllable two-dimensional moving devices with limited direct current discharge, and can realize the deposition of noble metal nanocatalyst arrays with different arrangement gaps and sizes on a substrate by controlling the moving speed of the device, the precursor flow rate and the gas velocity; and the fine control of InAs nanowire spacing is realized. Compared with the conventional solution preparation catalyst method, the steps are more simplified, the catalyst is directly printed on the substrate through the current, the reaction speed is accelerated, and the use of a chemical reducing agent is avoided; the catalyst particle size can be controlled by controlling the parameters, and then the reaction rate and the fineness of the nanowire product can be controlled; the catalyst particles prepared by the application carry charges, the aggregation of the catalyst is prevented under the electrostatic repulsion, the uniformity of the catalyst is ensured, and then the purity and the arrangement shape of the nanowire product are ensured.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of semiconductor material preparation, and in particular to a device for positioning preparation of an InAs nanowire array and a preparation method. BACKGROUND

[0002] Semiconductor nanowires are one-dimensional nanomaterials with a diameter less than 100 nm, which have unique physical and chemical properties beyond traditional bulk semiconductor materials and are considered to be the cornerstone of future electronic and photonic devices. Among them, III-V semiconductor nanowires are applied to high-mobility transistors, light-emitting diodes, lasers and solar cells due to their excellent electronic and optical properties. As a representative III-V semiconductor material, InAs nanowires have the advantages of high electron mobility, low effective mass, narrow band gap and good ohmic contact, and are key materials for high-speed electronic and near-infrared, mid-infrared light emission and detection applications.

[0003] At present, the mainstream growth method for obtaining size-controllable InAs nanowires is epitaxial growth under the V-L-S (vapor-liquid-solid) mechanism with Au, Ag, Pt nanoparticles as catalysts. In the growth process of the nanowires, the noble metal nanoparticles form a liquid eutectic alloy with In single element in the precursor vapor, and then the growth and deposition of InAs nanowires are carried out in the alloy droplet. The traditional method is to first reduce noble metal ions to obtain noble metal nanoparticles by using a chemical reducing agent, then transfer the noble metal nanoparticles to the substrate to form a noble metal catalyst, and finally combine chemical vapor deposition to grow nanowires. This method not only has complicated steps, harsh conditions and cannot precisely arrange the position of the catalyst, but also has poor controllability in the reaction process, and the obtained noble metal catalyst is easy to agglomerate, has wide size distribution and poor uniformity. In addition, the toxicity and residue of the chemical reducing agent will also affect the activity, purity and application range of the catalyst. Since the thickness of the nanowires under the V-L-S synthesis mechanism depends on the size of the catalyst, it is particularly crucial to find a suitable method to prepare noble metal catalysts with narrow size distribution and controllable gap. SUMMARY

[0004] The application aims at the above-mentioned shortcomings in the prior production technology, and provides a device for positioning preparation of an InAs nanowire array and a preparation method, which combines limited direct current discharge with an electrode device that can freely move on a two-dimensional plane, can arrange noble metal catalyst arrays of different patterns on the surface of a substrate by chemical vapor deposition, combines limited alternating current discharge with a columnar reaction furnace, reduces the reaction temperature while stimulating the reaction activity, promotes the growth of nanowires using the catalyst in a tubular furnace, and achieves the purposes of saving energy and improving the reaction speed.

[0005] The technical scheme adopted by the application is as follows:

[0006] A device for positioning preparation of InAs nanowire array, comprising a reaction furnace, a substrate, a metal plate and a reaction powder are placed in the reaction furnace;

[0007] The reaction furnace is connected with:

[0008] A gas supply assembly, comprising a hydrogen cylinder and an argon cylinder, the hydrogen cylinder and the argon cylinder are connected to the reaction furnace;

[0009] A syringe pump, the output end of which is connected to the reaction furnace;

[0010] A moving device, comprising a support on both sides of the reaction furnace, a center sliding beam is connected between the two supports; a stepping motor and a limit switch are installed on each support and the center sliding beam, the stepping motor and the limit switch are connected to the control mainboard; an electrode is provided on the center sliding beam, the electrode points to the substrate in the reaction furnace; the electrode is in communication with the pipeline of the syringe pump and the gas supply assembly;

[0011] A power supply assembly, comprising a direct current power supply and an alternating current power supply, the direct current is connected to the discharge electrode for printing noble metal nanocatalyst; the alternating current is connected to the metal plate for initiating and promoting the growth of InAs nanowire.

[0012] As a further improvement of the above technical solution:

[0013] The center sliding beam is perpendicular to the axis of the reaction furnace, the center sliding beam moves along the axis direction of the reaction furnace, and the movement path of the electrode is within the plane area of the substrate.

[0014] The output pipeline of the hydrogen cylinder and the argon cylinder is provided with a mass flow controller.

[0015] An electric arc is generated between the substrate and the electrode.

[0016] The metal plate is arranged on the two side quartz outer walls of the reaction furnace.

[0017] The positive electrode of the direct current power supply is connected to the electrode, the negative electrode is connected to the substrate and grounded; and a voltage stabilizing impedance is connected in the direct current power supply circuit.

[0018] The cathode of the alternating current power supply is connected to one of the metal plates, the grounded anode is connected to the other metal plate and grounded, and a voltage stabilizing impedance is connected in the alternating current power supply circuit.

[0019] A method for positioning preparation of nanowire array, using the device for positioning preparation of InAs nanowire array, comprising the following steps:

[0020] A noble metal solution A with a concentration of 0.1-0.5 mM is prepared with deionized water as the solvent, filled into a syringe and placed on the syringe pump;

[0021] Connecting reaction device: the substrate is put into the reaction furnace in advance, argon is input into the pipeline to remove air through the mass flow controller, and the movement path of the electrode is controlled by the mainboard control moving device;

[0022] A direct current is applied to the electrode, and the discharge power is controlled to be kept at 20-30 W to break through the argon to generate a discharge arc;

[0023] After the arc is generated, the noble metal solution A is delivered to the electrode through the injection pump, the flow rate of the noble metal solution A is between 0.02-0.05 mL / min, and the argon flow rate is kept between 40-50 sccm through the control mass flow controller; the noble metal nanocatalyst is uniformly deposited on the substrate under the condition that the electrode moves;

[0024] After 10-15 min of deposition, the injection pump is turned off, the reaction furnace is closed, and the heating switch is turned on, the argon is kept open, and the air in the reaction furnace is removed; the hydrogen bottle is opened to introduce hydrogen into the reaction furnace; the ratio of hydrogen to argon in the reaction furnace is 1:20;

[0025] After the reaction furnace is heated to 500-600 DEG C, the metal plate is connected to alternating current, the discharge power of the alternating current is controlled to be kept at 20-30 W, the dielectric barrier discharge arc is generated in the reaction furnace, and the constant temperature reaction is kept for 20-30 min;

[0026] After the reaction is completed, the heating switch and the alternating current are turned off, the hydrogen bottle and the argon bottle are closed after the temperature in the reaction furnace cools to room temperature, the reaction furnace is opened, and the substrate is taken out.

[0027] As a further improvement of the above technical solution:

[0028] The noble metal solution A is one of chloroauric acid, chloroplatinic acid and silver nitrate.

[0029] The reaction powder is InAs powder, which is placed at a distance of 1 / 4-1 / 3 from the tail end of the reaction furnace; and the substrate is placed at a distance of 1 / 4-1 / 3 from the head end of the reaction furnace.

[0030] The beneficial effects of the present application are as follows:

[0031] The present application is mainly distinguished from the conventional solution method for preparing catalyst. In the conventional operation, the catalyst prepared in the solution needs to be transferred to the substrate, and the transfer step is omitted in the present application, and the catalyst is directly printed on the substrate by using electric current. In the present application, electrons are used as reducing agents to replace the conventional solution reducing agents, and the advantages are that the solution reducing agent is easy to cause other impurities to mix into the catalyst product, affecting the purity and activity of the catalyst; and the electrons do not affect the purity and catalytic activity of the catalyst. At the same time, the reaction process can be started or interrupted at any time by connecting or cutting off the power supply, which has high controllability and cannot be realized by the conventional solution method.

[0032] In the present application, the reaction speed can be accelerated by the current printing mode, and the arrangement shape can be controlled by the two-dimensional moving device. By controlling various parameters, the size of the catalyst particles can be controlled, and since the catalyst particle size is related to the reaction intensity, the catalyst activity and reaction speed can be controlled, and finally the thickness of the nanowire growth is controlled.

[0033] The specific advantages of the control parameters of the present application are as follows:

[0034] In the present application, the controllable two-dimensional moving device is combined with the limited direct current discharge, and by controlling the device moving speed, the precursor flow rate and the gas speed, the noble metal nanocatalyst array with different arrangement gaps and sizes can be deposited on the substrate. In the test process of the present application, the arrangement, size and density of the noble metal catalyst are adjusted by controlling the precursor flow rate, gas speed, electrode moving speed and moving track, etc. through single factor experiment, and the spacing and size of the InAs nanowire are finely controlled, which is suitable for various process production requirements.

[0035] In the present application, the limited alternating current discharge is used to excite the reaction activity, so that the argon ionization generates active substances such as electrons, ions, free radicals, metastable atoms and radiation photons, and interacts with the InAs vapor, promotes the decomposition of InAs into In and As elemental gas, accelerates the speed of the formation of eutectic alloy of indium element and noble metal catalyst, and improves the growth speed of InAs nanowire under the VLS mechanism.

[0036] In the present application, direct current is used when printing the catalyst, and alternating current is used when growing the nanowire. In the alternating electric field, the growth direction of the nanowire is the same as the direction of the electric field, which has a guiding effect on the growth direction of the nanowire, and avoids the problem of chaotic growth of the nanowire in the conventional electric field.

[0037] In the present application, the electrons act as reducing agents, which can carry electrons on the catalyst particles. Under the action of electrostatic repulsion, the catalyst will not gather, so that the overall catalyst uniformity is better, and it is more in line with the expected raw material requirements. In the process of catalytic growth of nanowires, the size of each nanowire is very small, and the length, size and trend are consistent, so that the finally presented array shape is better.

[0038] The present application has the advantages of small equipment area and no need for expensive vacuum equipment, integrates the preparation of catalyst and the growth of nanowire, and does not move the substrate during the preparation process, avoiding the damage of the sample during the moving process. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 It is the overall structure schematic diagram of the present application.

[0040] Figure 2SEM morphology of Au noble metal nanocatalyst prepared for the embodiment 1 of the present application.

[0041] Figure 3 SEM morphology of Au noble metal nanocatalyst prepared for the embodiment 2 of the present application.

[0042] Figure 4 TEM morphology of Au noble metal nanocatalyst prepared for the embodiment 1 of the present application.

[0043] Figure 5-a EDX image of single InAs nanowire prepared for the embodiment 1 of the present application.

[0044] Figure 5-b SEM morphology of single InAs nanowire prepared for the embodiment 1 of the present application.

[0045] Figure 6 TEM morphology of InAs nanowire prepared for the embodiment 1 of the present application.

[0046] Figure 7 SEM morphology of InAs nanowire prepared for the embodiment 3 of the present application.

[0047] Figure 8 SEM morphology of InAs nanowire prepared for the embodiment 4 of the present application.

[0048] Figure 9 Super-depth-of-field three-dimensional microscope morphology of InAs nanowire prepared for the embodiment 1 of the present application.

[0049] Wherein: 1, a syringe pump; 2, a direct current power supply; 3, an alternating current power supply; 4, a control mainboard; 5, a three-way valve; 6, a moving device; 7, a voltage stabilizing impedance; 8, a columnar reaction furnace; 9, a substrate; 10, an electrode; 11, a metal plate; 12, a mass flow controller; 13, a hydrogen cylinder; 14, an argon cylinder. DETAILED DESCRIPTION

[0050] The specific embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0051] As shown in the figure, the device for positioning and preparing InAs nanowire array of the present embodiment comprises a reaction furnace, and the reaction furnace is placed with a substrate 9, a metal plate 11 and a reaction powder; Figure 1 The reaction furnace is connected with:

[0052] A gas supply assembly, comprising a hydrogen cylinder 13 and an argon cylinder 14, the hydrogen cylinder 13 and the argon cylinder 14 being connected to the reaction furnace,

[0053] A syringe pump 1, the output end of which is connected to the reaction furnace,

[0054]

[0055] ​The mobile device 6 comprises a support on both sides of the reaction furnace, and a center sliding beam is connected between the two supports; a stepping motor and a limit switch are installed on each support and the center sliding beam, and the stepping motor and the limit switch are connected to the control mainboard 4; an electrode 10 is arranged on the center sliding beam, and the electrode 10 points to the substrate 9 in the reaction furnace; the electrode 10 is in communication with the pipeline of the injection pump 1 and the gas supply assembly,

[0056] The power supply assembly comprises a direct current power supply 2 and an alternating current power supply 3, the direct current power supply 2 is connected to the electrode 10 for printing noble metal nanocatalyst, and the alternating current power supply 3 is connected to the metal plate 11 for initiating and promoting the growth of InAs nanowires.

[0057] The center sliding beam is arranged perpendicular to the axis of the reaction furnace, and the center sliding beam slides along the axis direction of the reaction furnace, and the movement path of the electrode 10 is within the planar area of the substrate 9.

[0058] The output pipeline of the hydrogen cylinder 13 and the argon cylinder 14 is respectively provided with a mass flow controller 12.

[0059] An electric arc is generated between the substrate 9 and the electrode 10.

[0060] The metal plate 11 is arranged on the quartz outer wall on both sides of the reaction furnace.

[0061] The positive electrode of the direct current power supply 2 is connected to the electrode 10, the negative electrode of the direct current power supply 2 is connected to the substrate 9 and grounded, and a voltage stabilizing impedance 7 is connected in the circuit of the direct current power supply 2.

[0062] The cathode of the alternating current power supply 3 is connected to one of the metal plates 11, the anode is connected to the other metal plate 11 and grounded, and a voltage stabilizing impedance 7 is connected in the circuit of the alternating current power supply 3.

[0063] The positioning method for preparing the nanowire array in the embodiment applies the device for positioning and preparing the InAs nanowire array, and comprises the following steps:

[0064] A noble metal solution A with a concentration of 0.1-0.5 mM is prepared by using deionized water as a solvent, and is filled into a syringe and placed on the injection pump 1;

[0065] The reaction device is connected: the substrate 9 is placed in the reaction furnace in advance, argon is input into the pipeline through the mass flow controller 12 to remove air, and the movement path of the electrode 10 is controlled through the control mainboard 4;

[0066] A direct current is applied to the electrode 10, and the discharge power is controlled to be kept at 20-30 W to break through the argon and generate a discharge arc;

[0067] After the arc is generated, the noble metal solution A is delivered to the electrode 10 by the injection pump 1, the flow rate of the noble metal solution A is between 0.02-0.05 mL / min, the flow rate of argon is kept between 40-50 sccm by controlling the mass flow meter; the noble metal catalyst is uniformly deposited on the substrate 9 in the state of moving the electrode 10;

[0068] After 10-15 min of deposition, the injection pump 1 is closed, the reaction furnace is closed, the heating switch is opened, the argon is kept open, the air in the reaction furnace is exhausted; the hydrogen bottle 13 is opened to introduce hydrogen into the reaction furnace; the ratio of hydrogen to argon in the reaction furnace is 1:20;

[0069] After the temperature in the reaction furnace is heated to 500-600 DEG C, the metal plate 11 is passed through alternating current, the discharge power of the alternating current is controlled to keep 20-30 W, the dielectric barrier discharge arc is generated in the reaction furnace, and the constant temperature reaction is kept for 20-30 min;

[0070] After the reaction is completed, the heating switch and the alternating current are closed, the hydrogen bottle 13 and the argon bottle 14 are closed, the reaction furnace is opened, and the substrate 9 is taken out.

[0071] The noble metal solution A is a soluble noble metal salt solution, such as silver nitrate, chloroplatinic acid, potassium chloroplatinate, ammonium chloroplatinate, chloroauric acid, potassium chloroaurate, sodium chloroaurate, ammonium tetrachloroaurate, etc.

[0072] The reaction powder is InAs powder, which is placed at 1 / 4-1 / 3 of the tail end of the reaction furnace; the substrate 9 is placed at 1 / 4-1 / 3 of the head end of the reaction furnace.

[0073] The specific structure and working principle of the application are as follows:

[0074] The main principle of the application is that the movable electrode 10 freely moving in the two-dimensional plane is combined with the limited direct current discharge technology, the problem that the bottom platform of the bearing material needs to be frequently moved when the conventional direct current discharge technology processes a large area is overcome, the complicated manual operation steps are avoided, and the full-automatic reaction process is realized.

[0075] Meanwhile, the application is different from the motor-controlled planar discharge moving device 6, and the combination mode can select the residence time of different areas according to actual needs, and realize the preparation of the noble metal nano-catalyst array with different sparse degrees in the same plane.

[0076] The furnace constant temperature heating technology and the limited alternating current discharge technology are combined, the slow heating and long time consumption of the tubular reaction furnace can be overcome, the alternating current discharge can realize the purpose of fast heating to the expected temperature and keeping constant temperature, the alternating current can accelerate the gasification of the InAs powder and activate the noble metal nano catalyst, the two can be combined to form the eutectic alloy, and the purpose of in-situ preparation of the nanowire is realized.

[0077] The preparation method does not need chemical reducing agent or oxidant, the nanowire array is uniformly arranged and the gap is controllable, the equipment has small floor area, safe and flexible operation process, strong controllability and wide applicability.

[0078] The equipment used in the application is as shown in the drawing. Figure 1 The three-way valve 5 is connected to the injection pump 1, the first interface of the injection pump 1 is connected to the three-way valve 5, the second interface of the three-way valve 5 is connected to the argon bottle 14, and the third interface of the three-way valve 5 is connected to the electrode 10 made of stainless steel.

[0079] The moving device 6 is two hollow rectangular moving supports located on both sides of the reaction furnace, and a center sliding beam is connected between the two moving supports. The electrode 10 is fixed on the center sliding beam, the control mainboard 4 is connected to the moving device 6, the moving mode of the moving device 6 is controlled, the center sliding beam is pushed to move along the axial direction of the reaction furnace, and the movement path of the electrode 10 in the plane area of the rectangular substrate 9 is further controlled during the whole reaction process. A stepping motor as a power source and a limit switch for controlling the sliding limit position along the axial direction of the reaction furnace are installed on the two side supports of the moving device 6, and a stepping motor and a limit switch for controlling the sliding limit position along the radial direction of the reaction furnace are installed on the center sliding beam. The stepping motors and the limit switches are controlled by the control mainboard 4, and in the embodiment, the control mainboard 4 is driven by the USB flash drive to run the program code set in advance.

[0080] Metal plates 11 are attached to both sides of the axial direction of the reaction furnace, and in the embodiment, copper plates are used, which are attached to the outer quartz wall of the reaction furnace, and the substrate 9 is placed in the reaction furnace and kept a certain distance from the electrode 10. The end of the reaction furnace is connected to the hydrogen bottle 13 and the argon bottle 14, and the output pipelines of the hydrogen bottle 13 and the argon bottle 14 are both provided with mass flow controllers 12.

[0081] The positive electrode of the direct current power supply 2 is connected to the electrode 10, the negative electrode of the direct current power supply 2 is connected to the substrate 9 and grounded, and a voltage stabilizing impedance 7 is arranged on the direct current circuit; the cathode of the alternating current power supply 3 is connected to a piece of copper plate, the anode is connected to another piece of copper plate and grounded, and a voltage stabilizing impedance 7 is arranged on the alternating current circuit.

[0082] The parameters of the above-mentioned equipment are as follows:

[0083] Electrode 10 tube length 5-10 cm, tube diameter in the range of 0.7-1 mm, tube outer diameter in the range of 1.2-2.4 mm;

[0084] Three-way valve 5 inner diameter in the range of 2-3 mm;

[0085] Substrate 9 size 5-8 mm; substrate 9 material is silicon or silicon dioxide, pipe connection material is polytetrafluoroethylene;

[0086] Stabilizing resistance 7 resistance is 20 kΩ;

[0087] Cylindrical reaction furnace 8 diameter is 5 cm, length is 20 cm;

[0088] Electrode 10 lower end and substrate 9 keep 1-2 mm spacing.

[0089] The preparation method comprises the following steps:

[0090] (1) Deionized water as solvent, configuration concentration is 0.1~0.5 mM noble metal solution A is filled into the syringe and placed on the injection pump 1;

[0091] (2) Connect the reaction device: open the quartz cover of the cylindrical reaction furnace 8, place the substrate 9 in the reaction furnace chamber in advance. The argon gas is transported into the pipeline by the mass flow controller 12 to exclude air, and the movement device 6 is controlled by the control mainboard 4 to further control the movement of the stainless steel electrode 10;

[0092] (3) Apply direct current to the stainless steel electrode 10, control the power of discharge to keep at 20-30 W to break through the argon gas to generate discharge arc; the arc is generated between the substrate 9 and the electrode 10;

[0093] (4) After the arc is generated, the flow rate of the noble metal solution A is kept between 0.02~0.05 mL / min by controlling the injection pump 1, and the argon gas flow rate is kept between 40-50 sccm by controlling the mass flow controller. The noble metal solution A is reduced to generate noble metal nanoparticles in the electrode 10, which are uniformly deposited on the substrate 9 carried by the arc;

[0094] (5) After 10-15 min, close the injection pump 1, close the two quartz covers of the cylindrical reaction furnace 8 and open the heating switch to make the space in the furnace airtight, keep the argon flux to exclude air in the furnace, and open the hydrogen bottle 13 to introduce a certain amount of hydrogen into the reaction furnace;

[0095] (6) After heating to a temperature of 500 ℃-600 ℃ in the furnace, apply alternating current to the copper plate, control the power of discharge to keep at 20-30 W, generate DBD (dielectric barrier discharge) arc in the reaction furnace, and constant temperature reaction for 20-30 min.

[0096] (7) After the reaction is completed, turn off the heating switch and the AC power, and after the temperature cools to room temperature, turn off the hydrogen cylinder 13 and the argon cylinder 14, open the reaction furnace, and take out the substrate 9.

[0097] Example 1:

[0098] In this example, a 0.1 mM chloroauric acid solution was prepared using deionized water as the solvent and was loaded into a 5 mL syringe, and the syringe was placed on the syringe pump 1. The argon cylinder 14 and the MFC software were turned on, and the argon flow rate was set to 30 sccm for 10 min to remove the air in the tube. The two-dimensional moving device 6 switch was turned on, and the stainless steel electrode 10 with a length of 5 cm, an inner tube diameter of 0.7 mm, and an outer tube diameter of 1.2 mm was moved on the silicon substrate 9 according to the planned path, and the DC power supply 2 and the syringe pump 1 were turned on. The power of the DC power supply 2 was set to 20 W, and the flow rate of the syringe pump 1 was set to 0.02 mL / min.

[0099] After 10 min of processing, the syringe pump 1 and the DC power supply 2 were turned off, and 0.5 g of InAs powder was placed at the tail end 1 / 4 of the columnar reaction furnace 8. Then, the electrode 10 was lifted and the reaction furnace was closed, and the columnar reaction furnace 8 was in a sealed state. The MFC switch was adjusted to make the argon flow rate reach 60 sccm and the hydrogen flow rate reach 10 sccm, and the air in the furnace was removed for 10 min. The heating switch of the reaction furnace was turned on, the heating temperature was set to 500 ℃, and the AC power supply 3 was turned on to keep the discharge power at 15 W, and an electric arc was generated in the furnace. After 20 min, the heating switch and the AC power supply 3 were turned off, and the product was taken out after the temperature in the furnace cooled to room temperature.

[0100] Example 2:

[0101] The difference between this example and Example 1 is that the electrode 10 used in this example has a length of 7 cm, an inner tube diameter of 1 mm, and an outer tube diameter of 2 mm, which serves as a comparative example of Example 1.

[0102] Example 3:

[0103] The difference between this example and Example 1 or Example 2 is that the reaction time in the reaction furnace is extended to 40 min.

[0104] Example 4:

[0105] The difference between this example and Example 1 is that the reaction time of the chloroauric acid solution is 20 min.

[0106] In the above examples, the SEM morphology of the Au nanocatalyst prepared in Example 1 and Example 2 is as follows: Figure 2 、 Figure 3As shown in the corresponding figures, the Au nano-catalyst is in a spherical shape with uniform size, and increasing the length of the stainless steel electrode 10 and the inner diameter of the tube will result in an increase in the size of the nano-particles. Figure 4 It is further proved from the figures that the Au nano-catalyst in Example One has uniform size.

[0107] SEM morphological characterization, EDX element analysis and TEM morphological characterization of the InAs nanowires prepared in Example One are shown in Figure 4 , Figure 5, as can be seen from the corresponding figures, the nanowires grow in a straight line and have obvious top-end structure, element analysis and TEM analysis show that the InAs prepared by this method conforms to the V-L-S (vapor-liquid-solid) growth mechanism.

[0108] SEM morphological characterization of the InAs nanowires prepared in Example Three and Example Four is shown in Figure 7 , Figure 8 , as can be seen from the figures, the InAs nanowires are uniformly arranged. The super-depth-of-field three-dimensional microscope image of the InAs nanowires prepared in Example One is shown in Figure 9 , the flat substrate surface in the figure again proves that the InAs nanowires are uniformly distributed.

[0109] The above description is an explanation of the present application, not a limitation of the application, the scope of the present application is defined in the claims, within the protection scope of the present application, any form of modification can be made.

Claims

1. An apparatus for positioning the preparation of an array of InAs nanowires, comprising a reactor, characterized in that: A substrate (9), a metal plate (11) and reaction powder are placed in the reaction furnace; The reaction furnace is connected with: A gas supply assembly, including a hydrogen cylinder (13) and an argon cylinder (14), each of which is provided with a pipeline leading into the reaction furnace, An injection pump (1) having an output end connected to the reaction furnace, A moving device (6) including supports located on both sides of the reaction furnace and a center sliding beam connected between the two supports; a stepping motor and a limit switch are mounted on each support and the center sliding beam, and the stepping motor and the limit switch are connected to a control mainboard (4); an electrode (10) is provided on the center sliding beam and points to the substrate (9) in the reaction furnace; the electrode (10) is in communication with the pipeline of the injection pump (1) and the gas supply assembly, A power supply assembly, including a direct current power supply (2) and an alternating current power supply (3), the direct current power supply (2) being connected to the electrode (10) for printing catalyst, and the alternating current power supply (3) being connected to the metal plate (11) for initiating and promoting InAs nanowire growth, The metal plate (11) is arranged on the quartz outer wall on both sides of the reaction furnace.

2. The apparatus for positioning preparation of InAs nanowire arrays as claimed in claim 1, wherein: The center sliding beam is arranged perpendicular to the axis of the reaction furnace, and the center sliding beam moves along the axis direction of the reaction furnace, and the movement path of the electrode (10) is within the planar area of the substrate (9).

3. The apparatus for positioning preparation of InAs nanowire arrays as claimed in claim 1, wherein: A mass flow controller (12) is mounted on the output pipeline of each of the hydrogen cylinder (13) and the argon cylinder (14).

4. The apparatus for positioning preparation of InAs nanowire arrays as claimed in claim 1, wherein: An electric arc is generated between the substrate (9) and the electrode (10).

5. The apparatus for positioning preparation of InAs nanowire arrays as claimed in claim 1, wherein: The positive electrode of the direct current power supply (2) is connected to the electrode (10), the negative electrode of the direct current power supply (2) is connected to the substrate (9) and grounded, and a voltage stabilizing impedance (7) is connected in the circuit of the direct current power supply (2).

6. The apparatus for positioning preparation of InAs nanowire arrays as claimed in claim 1, wherein: The cathode of the alternating current power supply (3) is connected to one of the metal plates (11), the anode is connected to the other metal plate (11) and grounded, and a voltage stabilizing impedance (7) is connected in the circuit of the alternating current power supply (3).

7. A method of positioning a nanowire array, comprising: The device for positioning and preparing InAs nanowire array according to claim 1 is applied, including the following steps: A noble metal solution A with a concentration of 0.1-0.5 mM is prepared with deionized water as a solvent, filled into a syringe and placed on the injection pump (1); The reaction device is connected: the substrate (9) is placed in the reaction furnace in advance, argon is input into the pipeline through the mass flow controller (12) to expel air, and the movement path of the electrode (10) is controlled by the moving device (6) through the control mainboard (4); A direct current is applied to the electrode (10), and the discharge power is controlled to be kept at 20-30 W to break through the argon and generate a discharge arc; After the electric arc is generated, the noble metal solution A is delivered to the electrode (10) through the injection pump (1), the flow rate of the noble metal solution A is between 0.02-0.05 mL / min, and the argon flow rate is kept between 40-50 sccm through the control mass flow controller; the noble metal nanocatalyst is uniformly deposited on the substrate (9) in the state of moving with the electrode (10); After 10-15 min of deposition, the injection pump (1) is turned off, the reaction furnace is closed, and the heating switch is turned on, the argon is kept unobstructed, and the air in the reaction furnace is expelled; Open the hydrogen bottle (13) to supply hydrogen to the reaction furnace; the ratio of hydrogen to argon in the reaction furnace is 1:20; After the reaction furnace is heated to 500-600 ℃, AC power is supplied to the metal plate (11) to control the discharge power at 20-30 W, to generate a dielectric barrier discharge arc in the reaction furnace, and keep the temperature constant for 20-30 min; After the reaction is completed, the heating switch and AC power are turned off, the temperature in the reaction furnace is cooled to room temperature, the hydrogen bottle (13) and the argon bottle (14) are turned off, the reaction furnace is opened, and the substrate (9) is taken out.

8. The method of claim 7, wherein the nanowire array is positioned by, The noble metal solution A is a soluble noble metal salt solution.

9. The method of claim 7, wherein the nanowire array is positioned to be prepared. The reaction powder is InAs powder, which is placed 1 / 4-1 / 3 away from the tail end of the reaction furnace; the substrate (9) is placed 1 / 4-1 / 3 away from the head end of the reaction furnace.

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