Single-walled carbon nanotube horizontal array and method of making same

Abstract

The application discloses a single-wall carbon nanotube horizontal array and a preparation method thereof. The preparation method comprises the following steps: S1, reconstructing the surface of a single-crystal sapphire substrate; S2, injecting a catalyst precursor into the reconstructed single-crystal sapphire substrate through ion injection; and S3, placing the substrate after the ion injection into a vertical spraying chemical vapor deposition device, so as to grow single-wall carbon nanotubes through vapor deposition perpendicular to the airflow of the vertical spraying. The growth area of the single-wall carbon nanotube horizontal array can reach one inch, the density can be up to 140 roots / micron, and the single-wall carbon nanotube horizontal array shows super high quality. The preparation method combines a laser scribing technology, an ion injection technology and a vertical spraying device, realizes the synchronous optimization of the surface reconstruction of a sapphire single-crystal substrate, the catalyst distribution thereon and the action mode of the airflow and the substrate, and thus the growth size, the density and the uniformity of the single-wall carbon nanotube horizontal array are significantly improved, and the method has the characteristics of controllability, stability and easy amplification.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of carbon nanotube preparation, and more particularly to a preparation method for greatly improving the growth size, distribution uniformity and density of a single-walled carbon nanotube horizontal array. BACKGROUND

[0002] In terms of geometric structure, a single-walled carbon nanotube can be regarded as a seamless hollow tube curled from a single layer of graphene, and the curling manner determines the different structures and also determines the many excellent physical and chemical properties of the carbon nanotube. Since its advent, the single-walled carbon nanotube has attracted widespread attention due to its unique geometric and electronic structure, and has shown great potential for application in many fields.

[0003] As a one-dimensional Dirac material, the electrical performance of the carbon nanotube is particularly outstanding. Since the effective mass of electrons and holes is zero, the carrier mobility is extremely high and the electron transport exhibits ballistic characteristics, so the carbon nanotube is often considered as one of the star materials that can continue Moore's Law and replace silicon in the "post-Moore era". Among the various integrated forms of carbon nanotubes, the horizontal array is a special integrated type in which single carbon nanotubes are arranged in parallel on the surface of a flat substrate. The preparation methods mainly include two categories: post-processing method and direct growth method. The post-processing method generally involves the dispersion and reorientation of carbon nanotubes, so this method often has the disadvantages of poor orientation of the horizontal array, multi-layer stacking of carbon nanotubes, introduction of defects and impurities, long time consumption, high cost, etc., so the direct growth method is usually a better choice.

[0004] Application orientation is the development goal of the carbon nanotube horizontal array, and further improving the purity, density, growth size and other indicators of the semiconductor is the only way to seek killer applications of carbon nanotube. In view of the current preparation status of the direct growth method, large growth size, uniform distribution and high density are in a dilemma. Although there are works that directly prepare a carbon nanotube horizontal array with a density of up to 130 roots / micron, this is only a very local standard, and the density of the carbon nanotube array on the entire substrate shows a very large differential distribution. Especially in the process of enlarging the size of the growth substrate, the overall density will be further reduced or the density distribution uniformity will be worse, which will be further magnified and become particularly prominent. Therefore, how to break through the current situation that the carbon nanotube horizontal array directly prepared by the traditional method is difficult to have large size, high uniformity and high density is the key to determining whether the carbon nanotube horizontal array can go to market and truly realize industrial application. SUMMARY

[0005] The present application proposes a preparation method for greatly improving the growth size, distribution uniformity and density of a single-walled carbon nanotube horizontal array in view of the problems existing in the current large-scale preparation of high-density single-walled carbon nanotube horizontal arrays.

[0006] The present application provides a single-walled carbon nanotube horizontal array, comprising a single-crystal sapphire substrate and parallelly arranged single-walled carbon nanotubes grown on the surface of the substrate, wherein the area of the single-crystal sapphire substrate is 0.24-5.07 cm 2 , and the density of the single-walled carbon nanotubes in the single-walled carbon nanotube horizontal array is 60-140 per micron.

[0007] The present application also provides a method for preparing a single-walled carbon nanotube horizontal array, comprising: S1, reconstructing the surface of a single-crystal sapphire substrate; S2, injecting a catalyst precursor into the reconstructed single-crystal sapphire substrate by ion implantation; and S3, placing the substrate after ion implantation in a vertical spraying chemical vapor deposition device to grow single-walled carbon nanotubes by vapor deposition perpendicular to the vertical spraying gas flow.

[0008] According to an embodiment of the present application, in the step S1, the single-crystal sapphire substrate is reconstructed by laser scribing, wherein the laser scribing is set at a frequency of 100 KHz, a Q pulse width of 0.1 s, a speed of 20 mm / s, and a cycle number of 100 or more, preferably 100-200.

[0009] According to another embodiment of the present application, the laser scribing is to scribe a grid on the substrate by laser, wherein the distance between two adjacent parallel scribes in the grid is 1-2 mm.

[0010] According to another embodiment of the present application, the substrate is annealed after laser scribing, wherein the annealing is to heat the substrate to 1100℃ for 3 h and keep the temperature for 8 h, then reduce the temperature to 300℃ under temperature control for 10 h, and then cool to room temperature naturally.

[0011] According to another embodiment of the present application, in the step S2, the catalyst precursor is iron ions.

[0012] According to another embodiment of the present application, in the step S2, the energy of the ion implantation is 5-20 keV.

[0013] According to another embodiment of the present application, in the step S2, the dose is 1×10 13 -1×10 14 ions / cm 2 .

[0014] According to another embodiment of the present application, in the step S2, the annealing is to heat the substrate to 1100℃ for 3 h and keep the temperature for 8 h, then reduce the temperature to 300℃ under temperature control for 10 h, and then cool to room temperature naturally.

[0015] According to another embodiment of the present application, the area of the single-crystal sapphire substrate is 0.24-5.07 cm2 .

[0016] The growth area of the single-walled carbon nanotube horizontal array of the present application can reach one inch, the density can be up to 140 per micron, and the array exhibits ultra-high quality. The preparation method combines laser scribing technology, ion implantation technology and vertical spraying equipment, realizes the synchronous optimization of the surface reconstruction of the sapphire single crystal substrate, the catalyst distribution thereon and the action mode of the gas flow and the substrate, thereby significantly improving the growth size, density and uniformity of the single-walled carbon nanotube horizontal array, and the method has the characteristics of controllability, stability, easy amplification and the like. In addition, the ion implantation technology provides more space for the selection of catalyst precursors, and by screening suitable catalyst precursors, it is expected to realize the fine control of the conductive properties and even the chiral structure of the carbon nanotube horizontal array, and therefore has very broad prospects. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 a is a schematic diagram of laser scribing treatment of a 10x10mm 2 α-Al2O3 substrate in Example 1, and a schematic diagram of the actual measured area distribution after annealing.

[0018] Figure 1 b-g are AFM photos of the surface morphology of different areas of a 10x10mm 2 α-Al2O3 substrate after annealing and laser scribing treatment in Example 1.

[0019] Figure 2 a is a schematic diagram of laser scribing treatment of a 10x10mm 2 α-Al2O3 substrate in Example 1, and a schematic diagram of the actual measured area distribution after annealing.

[0020] Figure 2 b-c are AFM photos of the surface morphology of different areas of a 10x10mm 2 α-Al2O3 substrate after annealing and laser scribing treatment in Example 1.

[0021] Figure 3 a is a schematic diagram of laser scribing treatment of a 10x10mm 2 α-Al2O3 substrate in Example 1, and a schematic diagram of the actual measured area distribution after annealing.

[0022] Figure 3 b is a schematic diagram of laser scribing treatment of a 10x10mm 2 α-Al2O3 substrate in Example 1, and a schematic diagram of the actual measured area distribution after annealing.

[0023] Figure 4a is the actual measured area distribution of the 10 x 10 mm 2 Actual measured area distribution of the α-ΑΙ203substrate after the second annealing.

[0024] Figure 4 b-c is the actual measured area distribution of the 10 x 10 mm 2 AFM image of the surface topography of the laser scribed α-ΑΙ203substrate after annealing.

[0025] Figure 5 is the schematic diagram of the vertical spray chemical vapor deposition apparatus used in Example 1.

[0026] Figure 6 a is the actual measured area distribution of the 10 x 10 mm 2 horizontal array of single-walled carbon nanotubes on the α-ΑΙ203substrate characterized by SEM in Example 1 after the series of treatments described above.

[0027] Figure 6 b-f are SEM images of the high density horizontal array of single-walled carbon nanotubes grown in different areas on the 10 x 10 mm 2 α-ΑΙ203substrate in Example 1.

[0028] Figure 7 a is the actual measured area distribution of the 10 x 10 mm 2 quality of single-walled carbon nanotubes on the α-ΑΙ203substrate characterized by Raman spectroscopy in Example 1.

[0029] Figure 7 b-f are Raman spectra of the array of single-walled carbon nanotubes in different areas on the 10 x 10 mm 2 α-ΑΙ203substrate in Example 1.

[0030] Figure 8 a is the schematic diagram of the laser scribing of the 10 x 10 mm 2 α-ΑΙ203substrate in Comparative Example 1, and the actual measured area distribution after annealing thereof.

[0031] Figure 8 b-g are AFM images of the surface topography of the laser scribed 10 x 10 mm 2 α-ΑΙ203substrate after annealing in Comparative Example 1.

[0032] Figure 9 a is the schematic diagram of the laser scribing of the 10 x 10 mm 2 α-ΑΙ203substrate in Comparative Example 2, and the actual measured area distribution after annealing thereof.

[0033] Figure 9 b-g are 10 x 10 mm α-Al203 substrates treated by laser scribing in Comparative Example 2 2 AFM images of the surface morphology of different regions of the α-Al203 substrate after annealing.

[0034] Figure 10 a-d are 10 x 10 mm α-Al203 substrates treated by laser scribing in Comparative Example 2 2 SEM images of the horizontal array of carbon nanotubes grown on the surface of the α-Al203 substrate.

[0035] Figure 11 a is a schematic diagram of the laser scribing treatment of a 10 x 10 mm α-Al203 substrate in Comparative Example 3, and a schematic diagram of the actual measured region distribution after annealing. 2 AFM images of the surface morphology of different regions of the α-Al203 substrate after annealing.

[0036] Figure 11 b-g are 10 x 10 mm α-Al203 substrates treated by laser scribing in Comparative Example 3 2 AFM images of the surface morphology of different regions of the α-Al203 substrate after annealing.

[0037] Figure 12 a is a schematic diagram of the laser scribing treatment of a 10 x 10 mm α-Al203 substrate in Comparative Example 4, and a schematic diagram of the actual measured region distribution after annealing.

[0038] Figure 12 b-g are 10 x 10 mm α-Al203 substrates treated by laser scribing in Comparative Example 4 2 AFM images of the surface morphology of different regions of the α-Al203 substrate after annealing.

[0039] Figure 13 a is a schematic diagram of the laser scribing treatment of a 10 x 10 mm α-Al203 substrate in Example 2, and a schematic diagram of the actual measured region distribution after annealing. 2 AFM images of the surface morphology of different regions of the α-Al203 substrate after annealing.

[0040] Figure 13 b-g are 10 x 10 mm α-Al203 substrates treated by laser scribing in Example 2 2 AFM images of the surface morphology of different regions of the α-Al203 substrate after annealing.

[0041] Figure 14 a-c are the growth results of the high-density horizontal array of carbon nanotubes in Example 3.

[0042] Figure 15 a-c are the growth results of the high-density horizontal array of carbon nanotubes in Example 4.

[0043] Figure 16 a is the actual measured area distribution of Example 5.

[0044] Figure 16 b-c are the AFM characterization results of the surface of the α-Al2O3 substrate in Example 5.

[0045] Figure 17 a-c are the growth results of the high-density horizontal array of carbon nanotubes in Example 5.

[0046] Figure 18 a-c are the growth results of the high-density horizontal array of carbon nanotubes in Example 6.

[0047] Figure 19 a-c are the growth results of the high-density horizontal array of carbon nanotubes in Example 7.

[0048] Figure 20 a-c are the schematic diagrams of the maximum area and the highest density of the high-density horizontal array of carbon nanotubes grown in Example 8. DETAILED DESCRIPTION

[0049] The present application will be described in detail below with specific embodiments.

[0050] The horizontal array of single-walled carbon nanotubes of the present application comprises a single-crystal sapphire substrate and single-walled carbon nanotubes grown on the surface of the substrate and arranged in parallel, the area of the single-crystal sapphire substrate is 0.24-5.07 cm 2 The density of the single-walled carbon nanotubes in the horizontal array of single-walled carbon nanotubes is 60-140 per micron.

[0051] The present application also provides a method for preparing a horizontal array of carbon nanotubes, comprising: S1, reconstructing the surface of a single-crystal sapphire substrate; S2, injecting a catalyst precursor into the reconstructed single-crystal sapphire substrate by ion injection; and S3, placing the substrate after the ion injection into a vertical shower chemical vapor deposition device to grow single-walled carbon nanotubes by vapor deposition perpendicular to the gas flow of the vertical shower.

[0052] In the step S1, the single-crystal sapphire substrate is reconstructed by laser scribing. The purpose of the reconstruction is to repair the lattice of the substrate and to reorganize the morphology. The laser scribing is set at a frequency of 100 KHz, a Q pulse width of 0.1 s, a speed of 20 mm / s, and a cycle number of 100 or more. Preferably, the cycle number is 100-200. In this step, the depth of the scribe is changed by changing the cycle number, and a scribe of a certain depth can produce a similar effect. Therefore, theoretically, other ways to form a scribe of a certain depth on the surface of the substrate can also achieve the purpose of the present application. Laser scribing has high controllability and can easily achieve the purpose of the present application.

[0053] In an optional implementation, laser scribing involves using a laser to scribble a grid on the substrate, with the distance between two adjacent parallel scribbles in the grid being between 1 and 2 mm. The scribble width can be approximately 20 μm.

[0054] In an optional embodiment, the substrate is annealed after laser scribing. Annealing may involve heating the substrate to 1100°C for 3 hours and holding it at that temperature for 8 hours, then cooling it to 300°C under controlled temperature for 10 hours, and finally allowing it to cool naturally to room temperature.

[0055] In the S2 step, the catalyst precursor is iron ions. The ion implantation energy is 5–20 keV. The dose is 1 × 10⁻⁶. 13 ~1×10 14 ions / cm 2 Of course, the catalyst precursor can also be other feasible ions, and the specific ion implantation energy and dosage can be determined by those skilled in the art through experimentation.

[0056] In an optional implementation, in step S2, annealing can be performed by heating the substrate to 1100°C for 3 hours and holding it at that temperature for 8 hours, then cooling it to 300°C under controlled temperature for 10 hours, and then allowing it to cool naturally to room temperature.

[0057] In an optional embodiment, the area of ​​the monocrystalline sapphire substrate is 0.24–5.07 cm². 2 .

[0058] The present invention will be further described below through specific examples. However, these examples are merely exemplary and do not constitute any limitation on the scope of protection of the present invention.

[0059] Unless otherwise specified, all reagents, materials and instruments used in the following examples and comparative examples are commercially available.

[0060] Example 1

[0061] Using a UV laser marking machine (model: HGTECH LSU3EA, 24w, 355nm) to mark 10×10mm 2 A single-sided polished α-Al₂O₃ substrate was scribing at a frequency of 100 kHz, a Q-pulse width of 0.1 μs, a speed of 20 mm / s, and 100 cycles. Patterns were etched onto the substrate surface as shown in the image. Figure 1 The grid shown ensures that each square grid has a size of 2×2mm. 2The substrate was cleaned in deionized water, high-purity acetone, and anhydrous ethanol, respectively, and then annealed in a muffle furnace. The furnace temperature was set to 1100 °C for 3 h and maintained at 1100 °C for 8 h, and then decreased to 300 °C by temperature programming for 10 h, and then naturally cooled to room temperature. A large-area single-crystal substrate with uniform surface morphology and exposed clean (11-20) surface was obtained. The surface morphology is shown in Figure 1 a-c. Figure 2 a-c are the AFM images of the surface morphology of the conventional 10 x 10 mm 2 The surface morphology of the α-Al2O3 substrate after the same cleaning and annealing treatment.

[0062] Then, the pretreated α-Al2O3 substrate was placed in an ion implanter (FAD-MEVVA) for iron ion implantation at room temperature. The ion implantation energy was 5 keV, and the dose was 1 x 1016 ions / cm2. 14 ions / cm 2 After the implantation, the substrate was again cleaned and annealed by the same steps as described above. The surface morphology of the α-Al2O3 substrate before and after the ion implantation and the second annealing treatment is shown in Figure 3 a and 3b. For comparison, Figure 4 a-c are the AFM images of the surface morphology of the conventional α-Al2O3 substrate after the second annealing treatment.

[0063] Figure 5 The vertical spray chemical vapor deposition device for preparing a large-area uniform high-density single-walled carbon nanotube horizontal array is a double-temperature-zone thermal resistance type vertical tube furnace. The highest experimental temperature can reach 1100 °C, and the actual temperature in a constant temperature state fluctuates within ± 1 °C of the set temperature. The tube furnace is internally provided with a spray head 100 and a lifting platform 200. Various carriers or substrates required for growing single-walled carbon nanotubes can be placed on the lifting platform. By adjusting the height of the lifting platform, the distance between the substrate surface and the spray head 100 can be controlled, thereby adjusting the uniformity of the growth of the large-area single-walled carbon nanotube array.

[0064] The above α-Al2O3 substrate was placed on a 200 mm lift platform in a spray chemical vapor deposition apparatus, and the distance between the lift platform and the showerhead was adjusted to 10 mm. The system was heated to 600 °C at a rate of 40 °C / min in air, and then a mechanical pump was started to pump the system to 20 Pa to remove air. Subsequently, 1000 sccm of argon was introduced to clean the system for 5 min. Then, the argon flow was adjusted to 300 sccm, and the furnace temperature was continuously increased to a reaction temperature of 830 °C. At this time, the pressure of the system was adjusted to 70 kPa, and 300 sccm of high-purity argon and 300 sccm of high-purity hydrogen were introduced for 3 min to pre-reduce the iron catalyst precursor injected in the surface layer of the α-Al2O3 substrate. Then, 14 sccm of argon was introduced into an ethanol tank to introduce the liquid carbon source in the form of bubbles into the growth system. After the above argon, hydrogen, and carbon source were fully pre-mixed, they were uniformly sprayed onto the surface of the α-Al2O3 substrate through the showerhead 100 to catalyze the directional growth of the horizontal array of single-walled carbon nanotubes. After 25 min of growth, the system returned to normal pressure, and the carbon source was turned off. The argon and hydrogen were maintained until the furnace naturally cooled to room temperature, and then the substrate was removed for subsequent characterization.

[0065] The growth results of the high-density carbon nanotube horizontal array obtained in this example are shown in FIGS. Figure 6 a-g. The SEM results at different magnifications all show that uniform carbon nanotube horizontal arrays can be grown in different regions on the entire surface of the α-Al2O3 substrate.

[0066] The single-walled carbon nanotube array prepared by this method was further proved to have ultra-high quality by Raman spectrum characterization. Five representative regions were selected on the α-Al2O3 substrate, as shown in FIG. Figure 7 a, and Raman characterization was performed using a 532 nm wavelength excitation light. The obtained spectrum (FIG. Figure 7 b-f) clearly shows the radial breathing vibration peak (RBM) and the tangential vibration peak (G) of the single-walled carbon nanotube, and almost no defect-induced peak (D) representing the structural defects of the carbon nanotube or carbon impurities other than the carbon nanotube. The obtained G / D peak intensity ratio can be greater than 100, proving that the single-walled carbon nanotube horizontal array prepared by this method has very high quality.

[0067] Comparative Example 1

[0068] When the α-Al2O3 substrate was processed by using an ultraviolet laser marking machine, the grid size was set to 4×4 mm 2 , and other parameters were the same as in Example 1.

[0069] The surface structure reorganization results of the treated α-Al2O3 substrate are shown in FIG. Figure 8 a-g, which proves that the grid size is too large to have a limited auxiliary effect on the uniform reorganization of the substrate surface.

[0070] Comparative Example 2

[0071] The grid size was set to 1 x 1 mm when the α-Al2O3 substrate was processed by the UV laser marking machine. 2 The other parameters were the same as in Example 1.

[0072] The results of the surface structure reorganization of the treated α-Al2O3 substrate are shown in Figure 9 a-g, which prove that too small grid size will bring more sputtering, affecting the orientation effect of the substrate on the carbon nanotubes in the subsequent growth process. The growth effect of the carbon nanotubes on the substrate is shown in Figure 10 a-d

[0073] Comparative Example 3

[0074] The cycle number was set to 1 when the α-Al2O3 substrate was processed by the UV laser marking machine, and the other parameters were the same as in Comparative Example 1.

[0075] The results of the surface structure reorganization of the treated α-Al2O3 substrate are shown in Figure 11 a-g, which prove that too shallow scratches have limited auxiliary effect on the uniform reorganization of the substrate surface.

[0076] Comparative Example 4

[0077] The cycle number was set to 50 when the α-Al2O3 substrate was processed by the UV laser marking machine, and the other parameters were the same as in Comparative Example 1.

[0078] The results of the surface structure reorganization of the treated α-Al2O3 substrate are shown in Figure 12 a-g, which are similar to those in Comparative Example 1.

[0079] Example 2

[0080] The cycle number was set to 200 when the α-Al2O3 substrate was processed by the UV laser marking machine, and the other parameters were the same as in Comparative Example 1.

[0081] The results of the surface structure reorganization of the treated α-Al2O3 substrate are shown in Figure 13 a-g, which prove that the auxiliary effect of the scratches on the uniform reorganization of the substrate surface is basically consistent when the scratch depth is greater than a certain value.

[0082] Example 3

[0083] The iron ion was injected into the α-Al2O3 substrate by the ion implanter, and the injection dose was 1 x 1016 ions / cm2, and the other parameters were the same as in Example 1. 13 ions / cm 2 ​

[0084] The carbon / hydrogen ratio was optimized to 14 / 500, and a large-area uniform high-density carbon nanotube horizontal array was directly prepared in a vertical spraying system, and the growth results are shown in Figure 14 a-c.

[0085] Example 4

[0086] When iron ions were injected into the α-Al2O3 substrate using an ion implanter, except that the injection dose was 5 x 1014 ions / cm2, other parameters were the same as in Example 1. 13 2 Example 2

[0087] The carbon / hydrogen ratio was optimized to 14 / 450, and a large-area uniform high-density carbon nanotube horizontal array was directly prepared in a vertical spraying system, and the growth results are shown in Figure 15 a-c.

[0088] Comparative Example 5

[0089] When iron ions were injected into the α-Al2O3 substrate using an ion implanter, except that the injection dose was 1 x 1014 ions / cm2, other parameters were the same as in Example 1. 16 2 Example 2

[0090] The above α-Al2O3 substrate after annealing was characterized by atomic force microscopy, and the results are shown in Figure 16 a-c, which proves that a large amount of nanometer particles with large size are precipitated during the annealing process when the ion injection dose is too large, and the subsequent carbon nanotube growth cannot be carried out.

[0091] Example 5

[0092] When iron ions were injected into the α-Al2O3 substrate using an ion implanter, except that the injection energy was 10 keV, other parameters were the same as in Example 1.

[0093] It is proved by scanning electron microscopy characterization that a large-area uniform high-density carbon nanotube horizontal array can also be directly prepared in a vertical spraying system under the above injection conditions, and the growth results are shown in Figure 17 a-c.

[0094] Example 6

[0095] When iron ions were injected into the α-Al2O3 substrate using an ion implanter, except that the injection energy was 15 keV, other parameters were the same as in Example 1.

[0096] The growth time was optimized to 50 min, and a large-area uniform high-density carbon nanotube horizontal array was directly prepared in a vertical spraying system, and the growth results are shown in Figure 18 a-c.​​

[0097] Example 7

[0098] The iron ions were implanted into the α-Al2O3 substrate using an ion implanter, and the parameters were the same as in Example 1 except that the implantation energy was 20 keV.

[0099] The growth time was optimized to 90 min, and a large-area uniform high-density carbon nanotube horizontal array was directly prepared in the vertical spraying system. The growth results are shown in Figs. 7a-c. Figure 19

[0100] Example 8

[0101] The iron ions were implanted into the α-Al2O3 substrate using an ion implanter, and the parameters were the same as in Example 1 except that the area of the α-Al2O3 substrate used was one inch and the distance of the shower head was 30 mm.

[0102] The scanning electron microscope characterization proved that a large-area uniform high-density carbon nanotube horizontal array was directly prepared in the vertical spraying system, and the atomic force microscope characterization proved that the highest density was 140 roots / micron. The characterization results are shown in Figs. 8a-c. Figure 20

[0103] The preferred embodiments of the present application disclosed above are only used to help explain the present application. The preferred embodiments do not describe all the details of the present application, and the present application is not limited to the specific embodiments described. Obviously, many modifications and variations can be made according to the content of the present specification. The present specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present application, so that those skilled in the art can well understand and utilize the present application. The present application is limited only by the claims and their full scope and equivalents.​​

Claims

1. A method for preparing a horizontal array of carbon nanotubes, characterized in that, include: S1, Reconstructing the surface of a single-crystal sapphire substrate; S2, the catalyst precursor is implanted into the reconstructed single-crystal sapphire substrate by ion implantation; and S3, the substrate after ion implantation is placed in a vertical spray chemical vapor deposition equipment, so that it is perpendicular to the vertical spray airflow for vapor deposition to grow single-walled carbon nanotubes. In step S1, the single-crystal sapphire substrate is reconstructed by laser scribing. The laser scribing is performed using an ultraviolet laser with a set frequency of 100 kHz, a Q pulse width of 0.1 s, a speed of 20 mm / s, and a cycle count of ≥100 times. The laser scribing involves using a laser to scribble a grid on the substrate, with the distance between two adjacent parallel scribbles in the grid being between 1 and 2 mm. After the laser scribing process, the substrate is annealed. The annealing process involves heating the substrate to 1100°C for 3 hours and holding it at that temperature for 8 hours, then cooling it to 300°C under controlled temperature for 10 hours, and finally allowing it to cool naturally to room temperature. In step S2, the catalyst precursor is iron ions, and the ion implantation energy is 5~20 keV, with a dose of 1×10⁻⁶. 13 ~1×10 14 ions / cm 2 Then, annealing is performed, which involves heating the substrate to 1100°C for 3 hours and holding it at that temperature for 8 hours, then cooling it down to 300°C under controlled temperature for 10 hours, and then allowing it to cool naturally to room temperature.

2. The preparation method according to claim 1, characterized in that, The number of cycles is 100 to 200.

3. The preparation method according to claim 1, characterized in that, The area of ​​the single-crystal sapphire substrate is 0.24~5.07 cm². 2 .

4. A horizontal array of carbon nanotubes, characterized in that, Prepared by the method according to any one of claims 1-3, comprising a single-crystal sapphire substrate and parallel-arranged single-walled carbon nanotubes grown on its surface, wherein the area of ​​the single-crystal sapphire substrate is 0.24~5.07 cm². 2 The density of single-walled carbon nanotubes in the horizontal array of single-walled carbon nanotubes is 60~140 nanotubes / micrometer.

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