Method for preparing Sb-doped SnO2 microwire by adopting chemical vapor deposition method

Abstract

The invention discloses a method for preparing a Sb-doped SnO2 microwire by adopting a chemical vapor deposition method. The method comprises the following steps: mixing stannous oxide powder, Sb2O3 powder and carbon powder according to a mass ratio of 10: (1-2): (11-12) to prepare reaction source material powder; putting the reaction source material powder into a quartz boat, covering the reaction source material powder with a cover plate, and pushing the quartz boat into a high-temperature heating area in a quartz tube of chemical vapor deposition equipment; introducing inert carrier gas; when the temperature of the high-temperature heating area reaches 1050-1150 DEG C, oxygen is introduced, the flow is controlled to be 20-50 ml / min, and the growth time is 30 minutes; and closing the oxygen after the growth is finished, continuously introducing the inert carrier gas, and cooling to obtain the Sb-doped SnO2 microwire. According to the method, the growth of the Sb-doped SnO2 microwire is realized in the quartz boat through reduction and oxidation reactions between source materials, the diameter of the grown Sb-doped SnO2 microwire is about 40-80 microns, the length of the grown Sb-doped SnO2 microwire is 0.2-1 cm, the preparation of the large-size Sb-doped SnO2 microwire with the length of 1 cm is realized, and the preparation convenience of a corresponding device is greatly improved; the method is simple to operate and low in cost, and the repeatability of the micron wire is high.

Description

Technical Field

[0001] The invention relates to the technical field of micron material preparation, and in particular to a method for preparing Sb-doped SnO2 micron wires by adopting a chemical vapor deposition method. Background Art

[0002] SnO2 is a Group IV-VI wide bandgap semiconductor material with a bandgap width of 3.6 eV. It has good transmittance in the visible light range, high carrier mobility, and good physical and chemical stability. It has broad application prospects in optoelectronic devices, gas sensors, photocatalysis and other fields.

[0003] At present, researchers' research on SnO2 materials is mainly focused on thin films and nanostructures. Compared with thin films and nanostructures, microwires have the advantage of high crystal quality, while large-sized microwires are also easy to operate under an optical microscope or the naked eye to prepare corresponding devices, which can greatly reduce the difficulty of device manufacturing.

[0004] Undoped intrinsic SnO2 exhibits n-type conductivity, but its electron concentration is low. Existing technology usually dopes elements such as Sb and F to achieve the purpose of increasing its electron concentration. However, there is no report on the use of chemical vapor deposition to prepare Sb-doped SnO2 microwires with a large size of up to 1 cm in length, high electron concentration and easy to prepare related devices. Summary of the invention

[0005] The present invention provides a method for preparing Sb-doped SnO2 micrometer wires by using a chemical vapor deposition method to solve the above problems.

[0006] In order to achieve the above object, the technical solution of the present invention is:

[0007] A method for preparing Sb-doped SnO2 micrometer wires by chemical vapor deposition method comprises the following steps:

[0008] S1: mixing tin oxide powder, Sb2O3 powder and carbon powder in a mass ratio of 10:(1-2):(11-12) to prepare a reaction source material powder;

[0009] S2: putting the reaction source material powder into a quartz boat, covering the quartz boat and the reaction source material powder with a plurality of cover sheets arranged in parallel, and then pushing the quartz boat into a high-temperature heating zone in a quartz tube of a chemical vapor deposition device;

[0010] S3: introducing an inert carrier gas at a flow rate of 150-200 ml / min into the quartz tube;

[0011] S4: When the heating temperature of the high temperature heating zone in the quartz tube reaches 1050-1150° C., oxygen as a reaction gas is introduced into the high temperature heating zone, the flow rate of oxygen is controlled at 20-50 ml / min, and the growth time is 30 minutes;

[0012] S5: After the growth is completed, the reaction gas oxygen is turned off, and the inert carrier gas is continued to be introduced. After the temperature is cooled to room temperature, the sample is taken out to obtain the Sb-doped SnO2 micrometer wire.

[0013] Furthermore, the cover sheet is made of sapphire or quartz, and the total length of a plurality of the cover sheets is 3 to 6 cm.

[0014] Furthermore, the purity of the stannous oxide powder is greater than 99%.

[0015] Furthermore, the inert carrier gas is argon.

[0016] The beneficial effects of the present invention are:

[0017] The present invention discloses a method for preparing Sb-doped SnO2 micron wires by chemical vapor deposition. The growth of Sb-doped SnO2 micron wires is achieved in a quartz boat through reduction and oxidation reactions between source materials. The diameter of the grown Sb-doped SnO2 micron wires is about 40 to 80 μm and the length is 0.2 to 1 cm. The preparation of large-size Sb-doped SnO2 micron wires with a length of 1 cm is achieved, which greatly improves the convenience of preparing corresponding devices. The method is simple to operate, low in cost, and the repeatability of the micron wires is strong. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 is a camera photo of the sample obtained in Example 1 of the present invention;

[0020] Figure 2 is a scanning electron microscope photograph of the sample obtained in Example 1 of the present invention;

[0021] Figure 3 is the X-ray diffraction pattern of the sample obtained in Example 1 of the present invention;

[0022] Figure 4 is a camera photo of the sample obtained in Example 2 of the present invention;

[0023] Figure 5is a camera photo of the sample obtained in Example 3 of the present invention;

[0024] Figure 6 This is a camera photo of the sample obtained in Comparative Example 1 of the present invention;

[0025] Figure 7 It is a scanning electron microscope photograph of the sample obtained in Comparative Example 2 of the present invention. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] Example

[0028] Embodiment 1:

[0029] A method for preparing Sb-doped SnO2 micrometer wires by chemical vapor deposition method comprises the following steps:

[0030] S1: fully mixing tin oxide powder with a purity greater than 99%, Sb2O3 powder and carbon powder in a mass ratio of 9:1:10 to prepare a reaction source material powder;

[0031] S2: Put the source material powder into the quartz boat and flatten it, cover the powder with three quartz sheets arranged in parallel along the length of the quartz boat as cover sheets, the length of the three cover sheets is 5 cm, and then push the quartz boat into the high temperature heating zone in the quartz tube of the chemical vapor deposition equipment;

[0032] S3: introducing argon gas at a flow rate of 150 ml / min into the quartz tube as a carrier gas;

[0033] S4: When the heating temperature of the equipment reaches 1080°C, oxygen as a reaction gas is introduced into the equipment, and its flow rate is controlled at 40 ml / min. The growth time is 30 minutes.

[0034] S5: After the growth is completed, the reaction gas oxygen is turned off and argon gas is continued to be introduced. When the temperature drops to room temperature, the quartz boat is taken out. A large number of transparent micrometer wires can be found growing at one end of the inner wall of the quartz boat. The transparent micrometer wires are Sb-doped SnO2 micrometer wires.

[0035] The camera photos of the samples obtained in Example 1 are as follows: Figure 1 As shown by Figure 1 It can be seen that the grown microwires are relatively dense, with the longest length being about 0.5 cm. Figure 2 This is a scanning electron microscope photograph of a single Sb-doped SnO2 micron wire. It can be seen from the figure that the surface of the Sb-doped SnO2 micron wire is very smooth and the diameter is uniformly about 50μm. Figure 3 This is the X-ray diffraction pattern of Sb-doped SnO2 micron wire. It can be seen from the figure that all diffraction peaks are consistent with the SnO2 standard card (JCPDS card, No.41-1445), indicating that the grown micron wire is tetragonal rutile SnO2. In addition, the energy dispersion spectrum of a single Sb-doped SnO2 micron wire was tested. The test results show that the molar percentage of Sb in the sample is about 2.6%, indicating that Sb is successfully doped.

[0036] Embodiment 2:

[0037] A method for preparing Sb-doped SnO2 micrometer wires by chemical vapor deposition method comprises the following steps:

[0038] S1: fully mixing tin oxide powder with a purity greater than 99%, Sb2O3 powder and carbon powder in a mass ratio of 6:1:7 to prepare a reaction source material powder;

[0039] S2: Put the source material powder into the quartz boat and flatten it, cover the powder with three quartz sheets arranged in parallel as cover sheets, the length of the three cover sheets is 5 cm, and then push the quartz boat into the high-temperature heating zone in the quartz tube of the chemical vapor deposition equipment;

[0040] S3: introducing argon gas at a flow rate of 150 ml / min into the quartz tube as a carrier gas;

[0041] S4: When the heating temperature of the equipment reaches 1080°C, oxygen as a reaction gas is introduced into the equipment, and its flow rate is controlled at 40 ml / min. The growth time is 30 minutes.

[0042] S5: After the growth is completed, the reaction gas oxygen is turned off and argon gas is continued to be introduced. When the temperature drops to room temperature, the quartz boat is taken out. A large number of transparent micrometer wires can be found growing at one end of the inner wall of the quartz boat. The transparent micrometer wires are Sb-doped SnO2 micrometer wires.

[0043] The scanning electron microscope photo of the sample obtained in Example 2 is as follows Figure 4 shown.

[0044] pass Figure 4 It can be seen that the sample of Example 2 of the present invention is a micrometer wire structure.

[0045] pass Figure 1 and Figure 4After comparison, it was found that with the increase of Sb doping amount, the length of the microwire became longer, and the length of most microwires exceeded 0.5cm, and the longest could reach 1cm. It was found that Sb doping can make the length of SnO2 microwire longer, and the diameter is about 70μm. By testing the Seebeck effect of a single Sb-doped SnO2 microwire, it was found that its heating end is positive and the cold end is negative, indicating that the conductivity type of the Sb-doped SnO2 microwire is n-type, and at the same length, diameter and heating temperature of 65°C, the thermovoltage value of the Sb-doped SnO2 microwire grown in Example 2 is 320mV, which is greater than the thermovoltage value of 300mV of the Sb-doped SnO2 microwire grown in Example 1, which indicates that the electron concentration in the microwire will increase with the increase of Sb doping amount.

[0046] Embodiment 3:

[0047] A method for preparing Sb-doped SnO2 micrometer wires by chemical vapor deposition method comprises the following steps:

[0048] S1: fully mixing tin oxide powder with a purity greater than 99%, Sb2O3 powder and carbon powder in a mass ratio of 9:1:10 to prepare a reaction source material powder;

[0049] S2: Put the source material powder into the quartz boat and flatten it, cover the powder with three quartz sheets arranged in parallel as cover sheets, the length of the three cover sheets is 5 cm, and then push the quartz boat into the high-temperature heating zone in the quartz tube of the chemical vapor deposition equipment;

[0050] S3: introducing argon gas at a flow rate of 150 ml / min into the quartz tube as a carrier gas;

[0051] S4: When the heating temperature of the equipment reaches 1130°C, oxygen as a reaction gas is introduced into the equipment, and its flow rate is controlled at 40 ml / min. The growth time is 30 minutes.

[0052] S5: After the growth is completed, the reaction gas oxygen is turned off and argon gas is continued to be introduced. When the temperature drops to room temperature, the quartz boat is taken out. A large number of transparent micrometer wires can be found growing at one end of the inner wall of the quartz boat. The transparent micrometer wires are Sb-doped SnO2 micrometer wires.

[0053] The scanning electron microscope photo of the sample obtained in Example 3 is as follows Figure 5 As shown. Figure 5 It can be seen that the sample of Example 3 of the present invention is a micron wire, and the maximum length of the micron wire is also more than 0.5 cm, and the diameter is about 80 μm. Moreover, when the growth temperature is higher than the growth temperature of Example 1, it is found that the growth position of the micron wire moves to one end of the boat, the distribution of the micron wire becomes more dense, and the diameter becomes larger.

[0054] Comparative Example:

[0055] Comparative Example 1:

[0056] The only difference from Example 1 is that in this comparative example, in step S2, only one cover sheet is used to cover the reaction source material powder, and the length of the cover sheet is about 1.5 cm.

[0057] The scanning electron microscope photo of the sample obtained in Comparative Example 1 is as follows Figure 6 shown.

[0058] pass Figure 6 It can be found that when only one quartz cover is added above the source material, the Sb-doped SnO2 micron wire grown in the boat is very short, with the longest length being only about 0.1 m. It can be seen that the number (length) of cover sheets plays a crucial role in the growth of Sb-doped SnO2 micron wires.

[0059] Comparative Example 2:

[0060] The only difference from Example 1 is that in this comparative example, Sb2O3 powder is not used in step S1, and only stannous oxide powder and carbon powder are mixed in a mass ratio of 1:1 as reaction source materials.

[0061] The scanning electron microscope photo of the sample obtained in Comparative Example 2 is as follows Figure 7 As shown. Figure 7 It can be found that for the sample not doped with Sb, a large number of SnO2 microwires are also grown in the boat, but the length of the grown microwires is about 0.2 cm to 0.3 cm. Compared with the doped Example 1, the length of the undoped microwire is shorter. In addition, the Seebeck effect test of a single SnO2 microwire shows that its conductivity type is n-type. At the same length, diameter and heating temperature of 65°C as Example 1, the thermovoltage value of the undoped SnO2 microwire is 190 mV.

[0062] In summary, the present invention discloses a method for preparing Sb-doped SnO2 micron wires by chemical vapor deposition, in which the growth of Sb-doped SnO2 micron wires is achieved in a quartz boat through reduction and oxidation reactions between source materials. The grown Sb-doped SnO2 micron wires not only have a high electron concentration, but also have a diameter of approximately 40 to 80 μm and a length of 0.2 to 1 cm, thereby achieving the preparation of large-size Sb-doped SnO2 micron wires with a length of up to 1 cm, greatly improving the convenience of preparing corresponding devices. The method is simple to operate, low in cost, and has strong repeatability in preparing micron wires.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing Sb-doped SnO2 micrometer wires by chemical vapor deposition, characterized in that: The following steps are involved: S1: mixing tin oxide powder, Sb2O3 powder and carbon powder in a mass ratio of 10:(1-2):(11-12) to prepare a reaction source material powder; S2: putting the reaction source material powder into a quartz boat, covering the quartz boat and the reaction source material powder with a plurality of cover sheets arranged in parallel, and then pushing the quartz boat into a high-temperature heating zone in a quartz tube of a chemical vapor deposition device; S3: introducing an inert carrier gas at a flow rate of 150-200 ml / min into the quartz tube; S4: When the heating temperature of the high temperature heating zone in the quartz tube reaches 1050-1150° C., oxygen as a reaction gas is introduced into the high temperature heating zone, the flow rate of oxygen is controlled at 20-50 ml / min, and the growth time is 30 minutes; S5: After the growth is completed, the reaction gas oxygen is turned off, and the inert carrier gas is continued to be introduced. After the temperature is cooled to room temperature, the sample is taken out to obtain the Sb-doped SnO2 micrometer wire.

2. The method for preparing Sb-doped SnO2 micrometer wires by chemical vapor deposition according to claim 1, characterized in that: The cover sheet is made of sapphire or quartz, and the total length of a plurality of cover sheets is 3 to 6 cm.

3. The method for preparing Sb-doped SnO2 micrometer wires by chemical vapor deposition according to claim 1, characterized in that: The purity of the stannous oxide powder is greater than 99%.

4. The method for preparing Sb-doped SnO2 micrometer wires by chemical vapor deposition according to claim 1, characterized in that: The inert carrier gas was argon.

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