A method for preparing tellurium nanowires and tellurium nanowires

Abstract

The application provides a preparation method of tellurium nanowires and the tellurium nanowires, and relates to the technical field of semiconductors. The preparation method comprises the following steps: S1, providing a clean substrate; S2, transmitting the substrate in step S1 into a molecular beam epitaxy (MBE) pretreatment chamber to perform a degassing treatment; S3, transmitting the substrate in step S2 into an MBE growth chamber to perform a deoxidation treatment; S4, reducing the substrate in step S3 to a growth temperature; S5, adjusting a tellurium source beam current to a growth value, and growing the tellurium nanowires on the substrate in step S4; wherein, steps S3-S5 are completed under the monitoring of high-energy electron diffraction; the substrate in steps S3-S5 is in a rotating state; and steps S1-S5 are performed in a vacuum environment. The preparation method provided by the application can realize the preparation of large-area high-purity and uniformly-shaped tellurium nanowire arrays.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a method for preparing tellurium nanowires and the tellurium nanowires. Background Art

[0002] Tellurium is a narrow-bandgap elemental semiconductor whose bandgap increases with decreasing thickness. A three-dimensional bulk material has a bandgap of 0.34 eV, while a single-atomic layer increases to 1 eV. Tellurium has potential applications in optoelectronics, thermoelectrics, piezoelectrics, catalysis, chemical sensing, and field emission. One-dimensional nanowires and nanosheets, with their unique geometries and properties, are ideal materials for developing future nanodevices. The controllable preparation of uniform nanowires over large areas is fundamental to their large-scale application and remains a persistent challenge in nanowire fabrication.

[0003] Tellurium has a unique chain-like crystal structure. Adjacent tellurium atoms on the same chain are connected by covalent bonds, while parallel adjacent chains are bound by van der Waals forces. This anisotropic atomic arrangement makes it easier for tellurium to form a one-dimensional structure. In related technologies, large-scale sheet-like tellurium nanowires can be prepared using a solution method, and these nanowires can be transferred and flattened onto substrates such as silicon oxide. Vapor transport is also used to prepare tellurium nanowires. Tellurium powder is usually placed at the high-temperature end of a quartz tube, and the tellurium powder is vaporized at high temperature to serve as a tellurium source. Argon or other inert gases are used as carrier gases to transport the tellurium source to the low-temperature substrate to form nanowires. The morphology, size, growth direction, etc. of the nanowires prepared by this method are closely related to the growth process. The two methods mentioned above are prone to introducing impurities into tellurium nanowires due to growth environment limitations. Furthermore, due to the different nanowire growth environments in the reactor and at different locations on the substrate, the uniformity of the nanowires is difficult to ensure. Therefore, the preparation of large-area, high-purity, and uniformly shaped tellurium nanowire materials remains difficult with current technology. Summary of the Invention

[0004] In view of the above problems, the present invention provides a method for preparing tellurium nanowires and tellurium nanowires, so as to realize the preparation of large-area, high-purity and uniformly formed tellurium nanowire arrays.

[0005] A first aspect of the present invention provides a method for preparing tellurium nanowires, the method comprising the following steps:

[0006] S1. Provide a clean substrate;

[0007] S2, transferring the substrate described in step S1 into a molecular beam epitaxy (MBE) pretreatment chamber for degassing;

[0008] S3, transferring the substrate described in step S2 into a molecular beam epitaxy (MBE) growth chamber for deoxidation treatment;

[0009] S4, cooling the substrate described in step S3 to a growth temperature;

[0010] S5, adjusting the tellurium source beam current to a growth value, and growing tellurium nanowires on the substrate in step S4;

[0011] Wherein, the steps S3 and S5 are completed under high energy electron diffraction monitoring; the substrate in the steps S3 and S5 is in a rotating state; and the steps S1 to S5 are performed in a vacuum environment;

[0012] The tellurium source beam is a tellurium single substance source beam, and the growth value of the tellurium single substance source beam is 1x10 -7 -1x10 -5 Torr, and the growth temperature is -200°C to 200°C.

[0013] In some embodiments, the substrate includes at least one of gallium arsenide, germanium, and mica.

[0014] In some embodiments, during the degassing process, the degassing temperature is 100° C.-400° C., and the degassing time is 0.5 hour-5 hours.

[0015] In some embodiments, during the deoxidation treatment, the deoxidation temperature is 200° C.-1000° C., and the deoxidation time is 0.1 hour-2 hours.

[0016] In some embodiments, the growth temperature is 25°C to 200°C.

[0017] In some embodiments, the growth value is 1x10 -7 Torr-5x10 -6 Torr.

[0018] In some embodiments, the growth time of the tellurium nanowires grown on the substrate in step S4 is 0.1 minutes to 1000 minutes, preferably 1 minute to 100 minutes.

[0019] In some embodiments, the substrate in step S5 is in a rotating state, and the rotation speed is 1 rpm to 60 rpm, preferably 6 rpm to 20 rpm.

[0020] A second aspect of the present invention provides a tellurium nanowire, which is prepared by the method for preparing the tellurium nanowire according to the first aspect of the present invention.

[0021] In some embodiments, the tellurium nanowires have an average length of 100 nm to 10,000 nm;

[0022] In some embodiments, the density of the tellurium nanowires is 1x10 8 / cm-2 -1x10 10 / cm -2 .

[0023] Through the above technical solution, the present invention has at least the following beneficial effects compared with the prior art:

[0024] (1) The preparation method of tellurium nanowires provided by the present invention utilizes molecular beam epitaxy (MBE) to grow in a high vacuum environment, which can effectively reduce the impurity content of the nanowire array and improve the purity of the tellurium nanowires;

[0025] (2) In the method for preparing tellurium nanowires provided by the present invention, the substrate is in a rotating state, which can effectively improve the large-area uniformity of the nanowire array and is conducive to the uniform growth of tellurium nanowires;

[0026] (3) The preparation method of tellurium nanowires provided by the present invention, using high energy electron diffraction monitoring (RHEED) facility detection and other means, can significantly improve the controllability of the vertical growth of tellurium nanowires, and enhance the growth uniformity and molding quality of tellurium nanowires;

[0027] (4) The preparation method of tellurium nanowires provided by the present invention is highly repeatable, simple and easy to implement, and can easily realize the industrial production of tellurium nanowires. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Shown is a schematic flow chart of the method for preparing tellurium nanowires provided by the present invention.

[0029] Figure 2 Shown are top and side views of the tellurium nanowires grown on a germanium substrate according to an embodiment of the present invention.

[0030] Figure 3 Shown are top and side views of the tellurium nanowires grown on a mica substrate according to an embodiment of the present invention.

[0031] Figure 4 Shown are the top view and side view of the tellurium nanowires grown at a growth time of 20 minutes in one embodiment of the present invention.

[0032] Figure 5 The figure shows that the growth value of the tellurium source beam is adjusted to 3.7x10 -7 Top and side views of the morphology of Torr-grown tellurium nanowires.

[0033] Figure 6 Shown are the top view and side view of the morphology of tellurium nanowires grown at a growth temperature of 225° C. in a comparative example of the present invention.

[0034] Figure 7The figure shows the growth value of the tellurium source beam at a growth temperature of 225°C and a value of 2.3x10 -7 Top view of the morphology of Torr-grown tellurium nanowires. DETAILED DESCRIPTION

[0035] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0036] As introduced in the background art, many studies have achieved the preparation of tellurium nanowires. However, due to different preparation methods, the growth results of tellurium nanowires vary greatly.

[0037] In some related technologies, large-scale, sheet-like tellurium nanowires can be produced using a solution method. This method involves placing a solution of a Te-containing compound in a hydrothermal reactor, where a chemical reaction generates tellurium nanowires. Centrifugal force is then used to separate the tellurium nanowires from the wastewater, and impurities are washed away with deionized water or other methods. These nanowires can be transferred to substrates such as silicon oxide, but the uniformity of the tellurium nanowires produced using this technique is poor. Transferring the nanowires to other substrates typically involves spin coating the nanowire-containing solution, resulting in the nanowires often lying flat on the substrate. Tellurium nanowires can also be produced using vapor transport methods. Tellurium powder is typically placed at the high-temperature end of a quartz tube and vaporized at high temperatures to serve as a tellurium source. Argon, or other inert gases, are used as carrier gases to transport the tellurium source to the low-temperature substrate, where the nanowires are formed. The morphology, size, and growth direction of the nanowires produced using this method are closely related to the growth process. By manipulating the growth process, various nanostructures with horizontal or vertical growth can be obtained. In this technique, the substrate is typically stationary. For large samples, varying temperatures and source concentrations at different locations on the substrate can easily lead to sample inhomogeneity. Furthermore, both methods, due to growth environment limitations, are prone to introducing impurities into tellurium nanowires, making them unsuitable for the preparation of high-purity nanowires.

[0038] In summary, due to the limitations of preparation methods, production equipment and other factors, the current preparation technology of tellurium nanowires cannot achieve wafer-level, ultra-high purity, high-density, and uniform vertical tellurium nanowire preparation.

[0039] In view of the above technical problems, the present invention provides a method for preparing tellurium nanowires, which comprises the following steps:

[0040] S1. Provide a clean substrate;

[0041] S2, transferring the substrate described in step S1 into a molecular beam epitaxy (MBE) pretreatment chamber for degassing;

[0042] S3, transferring the substrate described in step S2 into a molecular beam epitaxy (MBE) growth chamber for deoxidation treatment;

[0043] S4, cooling the substrate described in step S3 to a growth temperature;

[0044] S5, adjusting the tellurium source beam current to a growth value, and growing tellurium nanowires on the substrate in step S4;

[0045] Wherein, the steps S3 and S5 are completed under high energy electron diffraction monitoring; the substrate in the steps S3 and S5 is in a rotating state; and the steps S1 to S5 are performed in a vacuum environment;

[0046] The tellurium source beam is a tellurium single substance source beam, and the growth value of the tellurium single substance source beam is 1x10 -7 -1x10 -5 Torr, and the growth temperature is -200°C to 200°C.

[0047] Figure 1 FIG. 1 is a flow chart of the method for preparing tellurium nanowires provided by the present invention. Figure 1 As shown, the method for preparing tellurium nanowires provided by the present invention comprises the following steps:

[0048] S1. Provide a clean substrate;

[0049] Specifically, the substrate includes at least one of gallium arsenide, germanium, and mica, and there is no clear limitation on the crystal orientation, doping degree, etc. of the substrate.

[0050] S2, transferring the substrate described in step S1 into a molecular beam epitaxy (MBE) pretreatment chamber for degassing;

[0051] The substrate is introduced into the molecular beam epitaxy (MBE) pretreatment chamber for degassing, the purpose of which is to remove water vapor and other gases adsorbed on the substrate surface.

[0052] In some embodiments, during the degassing process, the degassing temperature is 100°C-400°C, for example, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, 190°C, 200°C, 210°C, 220°C, 230°C, 240°C, 250°C, 260°C, 270°C, 280°C, 290°C, 300°C, 310°C, 320°C, 330°C, 340°C, 350°C, 360°C, 370°C, 380°C, 390°C or 400°C; the degassing time is 0.5 hour-5 hours, for example, 0.5 hour, 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours, or 5 hours.

[0053] S3, transferring the substrate described in step S2 into a molecular beam epitaxy (MBE) growth chamber for deoxidation treatment;

[0054] The substrate is passed into the molecular beam epitaxy (MBE) growth chamber for deoxidation treatment. The deoxidation temperature and time are related to the specific type of substrate selected. During the deoxidation process, the oxide layer on the substrate surface will be removed under high temperature conditions, so the specific deoxidation temperature and time are related to the substrate type. The fresh surface of the substrate after deoxidation can reduce impurities in the material and better induce the epitaxial growth of the material, thereby effectively reducing the impurity content of the nanowire array. Moreover, the molecular beam epitaxy (MBE) method grows in a high vacuum environment, which can further reduce the impurity content of the nanowire array and significantly improve the purity of the tellurium nanowires.

[0055] In some embodiments, during the deoxidation treatment, the deoxidation temperature is 200° C.-1000° C., and the deoxidation time is 0.1 hour-2 hours.

[0056] In some embodiments, the substrate is a germanium substrate. During the deoxidation treatment, the deoxidation temperature is 400° C.-500° C., and the deoxidation time is 0.1 hour-2 hours.

[0057] In some embodiments, the substrate is a gallium arsenide substrate, and during the deoxidation treatment, the deoxidation temperature is 500° C.-700° C., and the deoxidation time is 0.1 hour-2 hours.

[0058] In some embodiments, the substrate is a mica substrate, and during the deoxidation treatment, the deoxidation temperature is 300° C.-600° C., and the deoxidation time is 0.1 hour-2 hours.

[0059] S4, cooling the substrate described in step S3 to a growth temperature;

[0060] Since the growth temperature of tellurium nanowires is lower than the deoxidation temperature of the substrate, the substrate temperature needs to be lowered to the growth temperature after the substrate is deoxidized.

[0061] In some embodiments, the growth temperature is between -200° C. and 200° C., for example, -200° C., -190° C., -180° C., -170° C., -160° C., -150° C., -140° C., -130° C., -120° C., -110° C., -100° C., -90° C., -80° C., -70° C., -60° C., -50° C., -40° C., -30° C., -20° C., -10° C., 0° C., 10° C., 20° C., 30° C., 40° C., 50° C., 60° C., 70° C., 80° C., 90° C., 100° C., 110° C., 120° C., 130° C., 140° C., 150° C., 160° C., 170° C., 180° C., 190° C., or 200° C. Growth temperature is a key factor affecting tellurium nanowires. While maintaining the tellurium source beam current constant, lowering the temperature is more conducive to the vertical growth of tellurium nanowires and increasing the nanowire density, but this may lead to a decrease in nanowire crystal quality. Conversely, increasing the growth temperature will reduce the nanowire density, and excessively high temperatures may even prevent the nanowires from growing vertically.

[0062] In a preferred embodiment, the growth temperature is between 25°C and 200°C. When the growth temperature is lower than 25°C (room temperature), it is necessary to add refrigeration equipment to the growth system or adopt other cooling methods, which increases costs and is not suitable for large-scale industrial production. However, when the growth temperature is too high, the nanowire morphology may become unstable or other defects may appear, or even the nanowires may not grow vertically.

[0063] S5, adjusting the tellurium source beam current to a growth value, and growing tellurium nanowires on the substrate in step S4;

[0064] When not in use, the beam current of the source is usually set very low. Before the growth of tellurium nanowires, the beam current of the tellurium source is adjusted to a growth value. In some embodiments, the growth value is 1x10 -7 -1x10 -5 Torr, for example, 1x10 -7 , 2x10 -7 , 3x10 -7 , 4x10 -7 , 5x10 -7 , 6x10 -7 , 7x10 -7 , 8x10 -7 , 9x10 -7 , 1x10 -6 , 2x10 -6 , 3x10 -6 , 4x10 -6 , 5x10 -6 , 6x10 -6 , 7x10 -6 , 8x10 -6 , 9x10-6 , 1x10 -5 The tellurium source beam current is a key parameter for nanowire growth. While maintaining the growth temperature unchanged, increasing the tellurium source beam current can increase the density and size of the nanowires.

[0065] In a preferred embodiment, the growth value is 1x10 -7 Torr-5x10 -6 Torr.

[0066] Specifically, in step S5, after the tellurium source beam is adjusted to the growth value, the main baffle is opened to start the growth of tellurium nanowires; after the tellurium nanowires grow to the target length, the tellurium source beam and the main baffle are closed to end the growth; finally, the temperature is lowered to room temperature; thus, the preparation of tellurium nanowires is completed.

[0067] Steps S3 and S5 are performed under high-energy electron diffraction (RHEED) monitoring. Specifically, both the substrate deoxidation treatment and the tellurium nanowire growth process are performed under RHEED monitoring. This is because RHEED is a device unique to molecular beam epitaxy (MBE) systems for observing the surface state of samples. RHEED monitors the substrate deoxidation treatment and tellurium nanowire growth process in real time, allowing for more precise control of substrate deoxidation and the growth direction of tellurium nanowires, as well as the formation uniformity of tellurium nanowires. This significantly improves the controllability of the vertical growth of tellurium nanowires, thereby enhancing the growth uniformity and formation quality of tellurium nanowires.

[0068] In the present invention, during the high-energy electron diffraction (RHEED) monitoring of step S3, during the deoxidation process of the substrate, RHEED can monitor the removal of oxides from the substrate surface in real time. Changes in the RHEED diffraction pattern can reflect the extent of oxide removal and surface smoothness of the substrate surface. When the diffraction pattern shows a clear fringe pattern, it indicates that the substrate surface is completely deoxidized and the atoms are arranged in an orderly and smooth manner.

[0069] In the present invention, during the high-energy electron diffraction (RHEED) monitoring process in step S5, the growth state, crystal structure, and surface morphology of the tellurium nanowires can be monitored in real time. By analyzing changes in the RHEED diffraction pattern, information such as the nucleation, growth rate, and crystal quality of the tellurium nanowires can be better controlled. This is crucial for optimizing growth parameters to improve the quality of the tellurium nanowires. Moreover, by further combining the design of appropriate growth temperature and beam growth values ​​for the tellurium nanowires, a wide range of control over the size and density of the tellurium nanowires can be achieved, resulting in the production of large-area vertical tellurium nanowire arrays with high purity and good uniformity.

[0070] The substrate in steps S3 and S5 is rotated; specifically, during the deoxidation treatment and tellurium nanowire growth process, the substrate is rotated. Rotating the substrate enhances the uniformity of the substrate surface temperature and source concentration, thereby effectively improving the large-area uniformity of the nanowire array and facilitating the uniform growth of the tellurium nanowires.

[0071] In some embodiments, the substrate in step S5 is in a rotating state, and the rotation speed is 1 rpm-60 rpm, for example, 1 rpm, 2 rpm, 3 rpm, 4 rpm, 5 rpm, 6 rpm, 7 rpm, 8 rpm, 9 rpm, 10 rpm, 15 rpm, 20 rpm, 25 rpm, 30 rpm, 35 rpm, 40 rpm, 45 rpm, 50 rpm, 55 rpm, and 60 rpm.

[0072] In a preferred embodiment, the rotation speed is 6 rpm to 20 rpm.

[0073] Wherein, the steps S1 to S5 are performed in a vacuum environment; performing the deoxidation treatment and the growth of the tellurium nanowires in a high vacuum environment is helpful to improve the purity of the tellurium nanowire array.

[0074] The tellurium source beam is a tellurium elemental source beam. The present invention uses tellurium elemental source as the tellurium source, which has high purity. Furthermore, compared with compound tellurium sources, high-purity elemental tellurium sources are less likely to introduce other elemental impurities, further improving the purity of tellurium nanowires.

[0075] In addition, the preparation method of tellurium nanowires provided by the present invention is highly repeatable, simple and easy to implement, and can easily realize the industrial production of tellurium nanowires.

[0076] In some embodiments, the substrate includes at least one of gallium arsenide, germanium, and mica.

[0077] Substrate cleanliness is essential for producing high-quality tellurium nanowires. If the substrate is a no-clean substrate, it can be directly transferred into the MBE pretreatment chamber. If the substrate is not a no-clean substrate, the substrate surface must be cleaned and dried with a nitrogen gun.

[0078] In some embodiments, the degassing process is performed at a temperature of 100°C to 400°C for a period of 0.5 to 5 hours. This process removes moisture and other gases adsorbed on the substrate surface. Degassing minimizes contamination of the substrate in the MBE growth chamber and the growth material.

[0079] In some embodiments, the degassed substrate is transferred to a molecular beam epitaxy (MBE) growth chamber for deoxidation. The quality of the deoxidation can be assessed using RHEED. The fresh surface of the deoxidized substrate reduces impurities in the material and better induces epitaxial growth.

[0080] In some embodiments, the growth time of the tellurium nanowires grown on the substrate in step S4 is 0.1 minutes to 1000 minutes, preferably 1 minute to 100 minutes.

[0081] A second aspect of the present invention provides a tellurium nanowire, which is prepared by the method for preparing the tellurium nanowire according to the first aspect of the present invention.

[0082] In some embodiments, the average length of the tellurium nanowires is 100 nm to 10,000 nm, for example, 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1000 nm, 2000 nm, 3000 nm, 4000 nm, 5000 nm, 6000 nm, 7000 nm, 8000 nm, 9000 nm, or 10,000 nm. The average length of the tellurium nanowires of the present invention can be measured by observing the electron microscopic morphology of the tellurium nanowires. The average length of the tellurium nanowires is related to the growth value of the tellurium source beam, the growth temperature, and the growth time.

[0083] In some embodiments, the density of the tellurium nanowires is 1x10 8 / cm -2 -1x10 10 / cm -2 , for example 1x10 8 / cm -2 , 2x10 8 / cm -2 , 3x10 8 / cm -2 , 4x10 8 / cm -2 , 5x10 8 / cm -2 , 6x10 8 / cm -2 , 7x10 8 / cm -2 , 8x10 8 / cm -2 , 9x10 8 / cm -2 , 1x10 9 / cm -2 , 2x10 9 / cm -2 , 3x10 9 / cm -2 , 4x10 9 / cm -2 , 5x10 9 / cm -2 , 6x10 9 / cm -2 , 7x10 9 / cm -2 , 8x10 9 / cm -2 , 9x10 9 / cm -2 , 1x10 10 / cm -2 The density of tellurium nanowires was tested by using a scanning electron microscope (SEM) to image the tellurium nanowire growth array sample and selecting a representative area (100 μm) from the microscopic image. 2 ) and use image analysis software to count the number of nanowires within that area. To improve accuracy, multiple different areas should be selected for statistical analysis and the average value taken. The tellurium nanowire arrays prepared by the present invention grow uniformly and vertically, with high growth quality.

[0084] The present invention will be described in further detail below with reference to specific examples. It should be understood that the following examples are merely illustrative and explanations of the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are encompassed within the scope of protection that the present invention is intended to protect.

[0085] Unless otherwise specified, the experimental methods used in the following examples are conventional methods; the reagents, materials, etc. used in the following examples are all commercially available unless otherwise specified.

[0086] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with 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 making creative efforts shall fall within the scope of protection of the present invention.

[0087] Example 1

[0088] The specific steps of the method for preparing tellurium nanowires are as follows:

[0089] Step 1: Attach a clean germanium substrate to a molybdenum support and place it in a molecular beam epitaxy (MBE) pretreatment chamber, where it is degassed at 400° C. for 1 hour.

[0090] Step 2: The degassed germanium substrate is transferred into a molecular beam epitaxy (MBE) growth chamber, deoxidized at 550° C. for half an hour, and then the substrate temperature is lowered to 150° C.

[0091] Step 3: Adjust the tellurium source beam pressure to 1.2x10 -6 Torr, after the beam stabilizes, open the main baffle and start growth.

[0092] Step 4: The growth time is 60 minutes, and the main baffle and the tellurium source beam main baffle are closed.

[0093] Step 5: Cool the substrate to room temperature.

[0094] in, Figure 2 The top view (Fig. (a)) and side view (Fig. (b)) of the tellurium nanowires grown on the germanium substrate in Example 1 are shown. The density of the tellurium nanowires can be measured from the top view (Fig. (a)), and the length of the tellurium nanowires can be measured from the side view (Fig. (b)). Specifically, Figure 2 The length of the tellurium nanowires is 2.925 μm, and the density of the tellurium nanowires is 2.5x10 9 / cm 2 .

[0095] Example 2

[0096] This embodiment is prepared by referring to the preparation method of embodiment 1, with the only difference being that the germanium substrate is replaced by a mica substrate.

[0097] in, Figure 3 Shown are the top view (Fig. (a)) and side view (Fig. (b)) of the tellurium nanowires grown on the mica substrate in Example 2 of the present invention. Specifically, Figure 3 The length of the tellurium nanowires is 3 μm and the density of the tellurium nanowires is 1.6x10 9 / cm 2 .

[0098] According to Example 1 and Example 2, high-density vertically grown tellurium nanowires were also grown on the mica substrate. The average length of the tellurium nanowires was about 3 μm, but the density of the tellurium nanowires was slightly lower. The tellurium nanowires on both substrates had excellent distribution uniformity. The tellurium nanowires grown on the mica substrate were slightly inferior to those grown on the germanium substrate.

[0099] Example 3

[0100] This embodiment is prepared by referring to the preparation method of embodiment 1, with the only difference being that the growth time of the tellurium nanowires is changed; specifically, the growth time is set to 20 minutes.

[0101] in, Figure 4The figures show the top view (Fig. (a)) and side view (Fig. (b)) of the tellurium nanowires grown for 20 minutes in one embodiment of the present invention. Figure 4 The length of the tellurium nanowires is 1.172 μm, and the density of the tellurium nanowires is 8x10 9 / cm 2 .

[0102] According to Example 1 and Example 3, the top view and side view of the tellurium nanowires grown for 60 minutes show that the length of the tellurium nanowires is 2.925 μm, which is longer than that of the 20-minute growth time, and the density is 2.5x10 9 / cm 2 Compared with 20 minutes, it has decreased. This shows that the length of tellurium nanowires is basically proportional to the growth time, and as the growth time increases, the density of tellurium nanowires will decrease. This is because some tellurium nanowires do not grow, the number of longer tellurium nanowires will be relatively reduced, and the density will decrease.

[0103] Example 4

[0104] This comparative example was prepared according to the method of Example 3, with the only difference being that the tellurium source beam current was changed. Specifically, the tellurium source beam current for growing tellurium nanowires was adjusted to 3.7×10 -7 Torr.

[0105] in, Figure 5 The figure shows that the growth value of the tellurium source beam is adjusted to 3.7x10 -7 Top view (Figure (a)) and side view (Figure (b)) of the morphology of Torr-grown tellurium nanowires.

[0106] According to Example 3 and Example 4, when the tellurium source beam current of the tellurium nanowire is 1.2x10 -6 Torr reduced to 3.7x10 -7 Torr, the density of tellurium nanowires is 8x10 9 / cm 2 Down to 5x10 9 / cm 2 , the length decreased from 1.172μm to 0.52μm. By comparison, it can be found that reducing the tellurium source beam current will cause the density and length of the nanowires to decrease, and the tellurium nanowires will appear slightly skewed and the edges of the tellurium nanowires will appear slightly bent, but most of the tellurium nanowires can grow vertically.

[0107] Comparative Example 1

[0108] This comparative example was prepared by referring to the preparation method of Example 1, with the only difference being that the growth temperature of the tellurium nanowires was changed; specifically, the growth time was set to 225°C.

[0109] in, Figure 6 Shown are the top view (Figure (a)) and side view (Figure (b)) of the tellurium nanowires grown at a growth temperature of 225°C in a comparative example of the present invention. Figure 6 The length of the tellurium nanowires is 1.2 μm, and the density of the tellurium nanowires is 1.2x10 9 / cm 2 .

[0110] By comparing Example 1 and Comparative Example 1, it can be found that increasing the growth temperature is not conducive to the vertical growth of tellurium nanowires. Some tellurium nanowires are obviously skewed, the tellurium nanowires become wider, the density decreases, and the edges of the tellurium nanowires are obviously bent.

[0111] Comparative Example 2

[0112] This comparative example was prepared by referring to the preparation method of comparative example 1, with the only difference being that the tellurium source beam current was changed. Specifically, the tellurium source beam current for growing tellurium nanowires was adjusted to 2.3x10 -7 Torr.

[0113] in, Figure 7 The figure shows that the growth value of the tellurium source beam is adjusted to 2.3x10 -7 Top view of the morphology of Torr-grown tellurium nanowires.

[0114] According to Comparative Examples 1 and 3, the growth temperature is 225°C, and when the tellurium source beam current is 1.2x10 -6 Torr reduced to 2.3x10 -7 Torr, e.g. Figure 7 As shown in the top view, the tellurium nanowires can no longer grow vertically and are lying flat, and their density is greatly reduced. In Comparative Example 2, the growth morphology of the tellurium nanowires is affected by two factors: the growth temperature and the tellurium source beam growth value. The growth value of the tellurium source beam is small and the growth temperature is too high at the same time, which will seriously affect the normal growth of the tellurium nanowires, thereby causing the growth quality of the tellurium nanowires to be greatly reduced.

[0115] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, various simple variations of the technical solution of the present invention may be made, including combining the various technical features in any other appropriate manner. These simple variations and combinations should also be regarded as disclosed in the present invention and fall within the scope of protection of the present invention.

Claims

1. A method for preparing tellurium nanowires, characterized in that: The preparation method comprises the following steps: S1. Provide a clean substrate; S2, transferring the substrate described in step S1 into a molecular beam epitaxy (MBE) pretreatment chamber for degassing; S3, transferring the substrate described in step S2 into a molecular beam epitaxy (MBE) growth chamber for deoxidation treatment; S4, cooling the substrate described in step S3 to a growth temperature; S5, adjusting the tellurium source beam current to a growth value, and growing tellurium nanowires on the substrate in step S4; Wherein, the steps S3 and S5 are completed under high energy electron diffraction monitoring; the substrate in the steps S3 and S5 is in a rotating state; the steps S1 to S5 are performed in a vacuum environment; The tellurium source beam is a tellurium single substance source beam, and the growth value of the tellurium single substance source beam is 1x10 -7 -1x10 -5 Torr, and the growth temperature is -200°C~200°C.

2. The method for preparing tellurium nanowires according to claim 1, wherein: The substrate includes at least one of gallium arsenide, germanium, and mica.

3. The method for preparing tellurium nanowires according to claim 1, wherein: During the degassing process, the degassing temperature is 100° C.-400° C., and the degassing time is 0.5 hour-5 hours.

4. The method for preparing tellurium nanowires according to claim 1, wherein: During the deoxidation treatment, the deoxidation temperature is 200° C.-1000° C., and the deoxidation time is 0.1 hour-2 hours.

5. The method for preparing tellurium nanowires according to claim 1, wherein: The growth temperature is 25°C to 200°C.

6. The method for preparing tellurium nanowires according to claim 5, wherein: The growth value is 1x10 -7 Torr-5x10 -6 Torr.

7. The method for preparing tellurium nanowires according to claim 6, wherein: The growth time of the tellurium nanowires on the substrate in step S4 is 0.1 minutes to 1000 minutes.

8. The method for preparing tellurium nanowires according to claim 1, wherein: In step S5, the substrate is in a rotating state, and the rotation speed is 1 rpm to 60 rpm.

9. A tellurium nanowire, characterized in that: The tellurium nanowires are prepared by the method for preparing tellurium nanowires according to any one of claims 1 to 8.

10. The tellurium nanowire according to claim 9, characterized in that The average length of the tellurium nanowires is 100 nm to 10000 nm.

11. The tellurium nanowire according to claim 9, characterized in that The density of the tellurium nanowires is 1x10 8 / cm -2 -1x10 10 / cm -2 .

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