Preparation method of silicon tellurium heterojunction based on molecular beam epitaxial growth
By using molecular beam epitaxy (MBE) technology, optimizing substrate processing and parameter control, and using silicon nanoribbons as templates to guide the orderly arrangement of tellurium atoms, the problem of precise control in the preparation of silicon-tellurium heterojunctions has been solved. This has enabled the growth of silicon-tellurium heterojunctions with well-organized structures and stable performance, thus promoting the application of quantum devices.
Patent Information
- Application Number
- CN202511282415.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-09
- Publication Date
- 2025-12-12
AI Technical Summary
In existing technologies, the preparation of silicon-tellurium heterojunctions lacks precise control, the growth mechanism is unclear, and it is difficult to achieve heterojunctions with regular structure and stable performance.
By employing molecular beam epitaxy (MBE) technology and optimizing substrate treatment, silicon nanoribbon growth, and tellurium atom deposition parameters, silicon nanoribbons are used as templates to guide the orderly arrangement of tellurium atoms, forming a well-structured silicon-tellurium heterojunction.
The growth of high-quality, large-area single-layer two-dimensional silicon tellurium heterostructures was achieved, and the electronic properties of the heterojunction were optimized, laying the foundation for subsequent electronic doping and performance optimization, and helping its application in quantum devices.
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Figure CN121110174A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of two-dimensional material growth and preparation, and particularly relates to a preparation method of a silicon-tellurium heterojunction based on molecular beam epitaxy growth. BACKGROUND
[0002] The discovery of graphene and its superior physical properties and great application potential have inspired people to open the door to explore the world of other two-dimensional atomic crystal materials and structural regulation. With the development of crystal material preparation methods in recent years, people have made great efforts to find two-dimensional (2D) materials composed of other group 14 elements. In particular, silicon, due to its similar valence electron structure to carbon, and their wide use in the semiconductor industry. Siliconene is a new type of two-dimensional (2D) material with a structure similar to graphene, as it has the advantage of being compatible with existing semiconductor technology. Comparing the chemical and physical properties of two-dimensional siliconene and graphene, it is found that the electronic properties of siliconene and graphene are similar, and in the past few years of theoretical research, it has been found that the energy band structure of siliconene exhibits half-metallic characteristics, and the high-symmetry point at the Brillouin zone is linearly related, which reflects the characteristics of massless Dirac fermions. From the experimental results, two-dimensional siliconene sheets synthesized on silver surfaces can observe parallel honeycomb structures of one-dimensional nanobands, with high aspect ratio self-assembly structures, which can be used as atomic-level growth templates for foreign atoms (such as tellurium atoms), providing an ideal substrate for constructing silicon-based heterojunctions.
[0003] Siliconene nanobands have application potential in electronic devices, optoelectronic devices, and chemical sensors, and can even be used in biomedical materials, with wide application in cell culture, tissue engineering, and other fields. Siliconene, as a two-dimensional nanomaterial with special properties, has been widely used in many fields, and with the development of technology in the future, the application fields of siliconene will continue to expand.
[0004] Tellurium (Te) and telluride materials exhibit excellent plasmonic properties and tunable band gaps at the nanoscale, with significant application potential in thermoelectric materials, quantum devices, and infrared detectors. However, current research on the ordered growth of tellurium-based nanostructures (such as tellurium chains) on silicon nanobands and the formation mechanism of silicon-tellurium heterojunctions is still relatively lacking, and the specific adsorption position of tellurium atoms on silicon nanobands, growth rules, and electronic regulation mechanisms of heterojunctions have not been clearly defined.
[0005] Therefore, there is an urgent need to propose a method for fabricating silicon-tellurium heterojunctions based on molecular beam epitaxy (MBE) to address the shortcomings of existing technologies. While the growth of silicon nanoribbons largely relies on metal substrates such as Ag(110), the synergistic growth conditions between silicon nanoribbons and tellurium atoms have not been optimized. Furthermore, the fabrication of silicon-tellurium heterojunctions lacks precise control over growth parameters, making it difficult to achieve heterojunctions with regular structures and stable performance. Thus, developing a method for fabricating silicon-tellurium heterojunctions using silicon nanoribbons as templates based on molecular beam epitaxy (MBE) technology, and clarifying the growth mechanism and structure-performance relationship of the heterojunction, has become a key requirement in current low-dimensional materials research. Summary of the Invention
[0006] To address the issues of insufficient precision control and unclear growth mechanisms in the fabrication of silicon-tellurium heterojunctions in existing technologies, this application provides a method for fabricating silicon-tellurium heterojunctions based on molecular beam epitaxy. The core of this method is to optimize the parameters of substrate treatment, silicon nanoribbon growth, and tellurium atom deposition, using silicon nanoribbons as a one-dimensional template to guide the orderly arrangement of tellurium atoms, thereby forming a structurally regular silicon-tellurium heterojunction, and to clarify the growth law of the heterojunction.
[0007] The technical solution of this application is as follows:
[0008] A method for preparing a silicon-tellurium heterojunction based on molecular beam epitaxy includes the following steps:
[0009] Step S1. The metal substrate is subjected to argon ion etching and annealing in sequence to remove surface impurities and obtain a clean metal substrate;
[0010] Step S2. Silicon atoms are deposited on the surface of the metal substrate and then annealed to obtain silicon nanoribbons. The goal is to obtain one-dimensional ordered single-chain silicon nanoribbons and multi-chain silicon nanoribbon structures on the surface of the metal substrate. The deposition time is 16 min.
[0011] Step S3. Deposit tellurium atoms on the surface of silicon nanoribbons using molecular beam epitaxy to obtain a silicon-tellurium heterojunction. The deposition time is 10 min.
[0012] By using the above technical solution, the inherent drawbacks of the top-down approach are avoided. This application uses Si and Te as precursors and selects the bottom-up molecular beam epitaxy method. First, a silicon nanoribbon structure with a flat and regular surface is deposited and annealed on the surface of a metal substrate to obtain a silicon nanoribbon structure. Then, Te is deposited on this surface to obtain a high-quality, large-area monolayer two-dimensional silicon-tellurium heterostructure.
[0013] Preferably, the metal substrate is an Ag metal substrate.
[0014] Preferably, the Ag metal substrate is an Ag(110) single crystal.
[0015] By using Ag as the substrate, better uniformity and a Te chain structure can be obtained because there is a good match between the lattice constants of Si and Ag, which are 3 / 4. The Si / Ag phase diagram shows that below ~1070K, the solid-phase miscibility of Si and Ag is negligible, and their close electronegativity indicates that the charge transfer between the silicon capping layer and the silver substrate is very small.
[0016] Preferably, in step S1, the argon gas pressure is controlled to be 1.2 × 10⁻⁶ during argon ion etching. -5 mbar, etching time 25-30 min, beam current I flax The current is 10.49A. The annealing process involves adjusting the current and voltage parameters to 1.4A and 14.7V for 16 minutes.
[0017] Preferably, in step S2, when depositing silicon atoms, the deposition current is 5.4A and the voltage is 8.1V. After deposition, the silicon atoms are annealed at 473K for 16 minutes.
[0018] To remove gases and impurities adsorbed on the surface of the silver substrate, the metal substrate is pretreated by Ar+ sputtering and annealing. Argon etching is then performed in a vacuum environment, which effectively removes gas molecules adsorbed on the surface of the silver substrate, thereby avoiding the influence of gas molecules on the metal substrate, the evaporation beam, and the two atomic chemical reactions.
[0019] Preferably, the deposition temperature is 462K when depositing tellurium atoms in step S3.
[0020] Preferably, the silicon wafer used for depositing silicon atoms has a purity of 99.99%.
[0021] Preferably, the purity of the tellurium source used for depositing tellurium atoms is 99.99%.
[0022] The beneficial effects of this application are as follows:
[0023] (1) The molecular beam epitaxy (MBE) growth technology provided in this application, on the one hand, is a method for growing tellurium chains using silicon nanoribbons as templates. Based on an ultra-high vacuum platform, a MBE system is built, which can precisely control the growth conditions and achieve controllable growth of two-dimensional materials. Utilizing the one-dimensional space of silicon nanoribbons as a template provides guidance for the growth of silicon-tellurium heterojunctions, promoting the orderly arrangement of tellurium atoms along the silicon nanoribbons to form silicon-tellurium heterojunctions, and further forming structurally regular Te chains. On the other hand, it optimizes the electronic properties of the heterojunction. In the silicon-tellurium heterojunction, the Dirac point of the silicon nanoribbons can be controlled through the adsorption of tellurium atoms, laying the foundation for subsequent electronic doping and performance optimization of the heterojunction, and facilitating its application in quantum devices.
[0024] (2) The preparation process of this application is simple, no harmful substances are generated, it is easy to prepare, and the production efficiency is high. Attached Figure Description
[0025] The specific embodiments of this application will be described in further detail below with reference to the accompanying drawings.
[0026] Appendix Figure 1 This is a schematic diagram of the clean Ag(110) substrate of this application;
[0027] Appendix Figure 2 This is a schematic diagram of the silicon nanoribbons grown in this application;
[0028] Appendix Figure 3 This is a schematic diagram of the silicon-tellurium heterostructure grown in this application;
[0029] Figure 4(a) is a schematic diagram of the silicon-tellurium heterostructure grown by depositing Te atoms on silicon nanoribbons (Si NRs) for different times (2 min).
[0030] Figure 4(b) is a schematic diagram of the silicon-tellurium heterostructure grown by depositing Te atoms on silicon nanoribbons (Si NRs) at different times (4 min).
[0031] Figure 4(c) is a schematic diagram of the silicon-tellurium heterostructure grown by depositing Te atoms on silicon nanoribbons (Si NRs) for different times (8 min).
[0032] Appendix Figure 5 This is a scanning tunneling microscope image of the sample prepared in Comparative Example 4;
[0033] Figure 6 is a scanning tunneling microscope image of the sample prepared in Comparative Example 5;
[0034] Appendix Figure 7 This is a scanning tunneling microscope image of the sample prepared in Comparative Example 6;
[0035] Appendix Figure 8 This is a scanning tunneling microscope image of the sample prepared in Comparative Example 7. Detailed Implementation
[0036] To further illustrate the technical means and effects adopted by this application in order to achieve the intended purpose of the invention, the following detailed description of the specific implementation methods, structures, features and effects of this application is provided in conjunction with the accompanying drawings and preferred embodiments.
[0037] Example 1
[0038] This embodiment provides a method for preparing a silicon tellurium heterojunction based on molecular beam epitaxy, as detailed below:
[0039] Step S1. Metal substrate processing
[0040] After the Ag(110) substrate is transferred to the sample stage, the position of the sample stage in the prep chamber is adjusted up, down, left, right, forward, and backward so that the Ag(110) substrate and the argon ion gun are at the same horizontal level. Then, the mechanical displacement stage is rotated so that the Ag(110) substrate is directly facing the argon ion gun. The micro-leak valve of the argon ion gun is adjusted to release argon gas. At this time, the argon gas pressure is maintained at 1.2 × 10⁻⁶. -5 mbar; the argon ion sputtering parameters were adjusted via the argon ion gun control system: emission current 6mA, accelerating voltage 1kV, sputtering time 30min, and beam current I. flax The current was 10.49 A. After argon ion sputtering, the Ag(110) substrate was annealed for surface reconstruction. The sample was preheated by adjusting the current of the DC regulated power supply, and then its current and voltage parameters were slowly adjusted to 1.4 A and 14.7 V. At this time, the sample temperature slowly increased to about 550 °C. After 16 minutes, the sample temperature reached 690-695 °C. Then the current of the DC regulated power supply was slowly reduced to 0.
[0041] After the initial treatment, the impurities on the Ag(110) substrate surface were mostly removed, but a small amount remained. Furthermore, the Ag(110) surface was not yet sufficiently smooth, necessitating a second surface treatment. The parameters for the second treatment were the same as the first, with the primary goal of making the Ag(110) substrate surface smoother and the individual mesa larger. A third treatment was then performed, with the same parameters as the first. This third treatment resulted in even larger individual mesa on the Ag(110) substrate. After multiple treatments, a clean Ag(110) substrate was obtained. The characterization results of this substrate using a low-temperature scanning tunneling microscope are as follows: Figure 1 As shown, the silver substrate is relatively clean and flat.
[0042] Step S2. Silicon Atom Deposition
[0043] After processing the Ag(110) substrate in the prep chamber, the substrate was transferred to the MBE chamber for silicon nanoribbon growth. Highly ordered silicon nanoribbons were grown using molecular beam epitaxy. A silicon wafer with dimensions of 10mm × 3mm and a purity of 99.99% was used as the evaporation source. A DC regulated power supply was used to apply current (5.2A, 7.0V) to the silicon wafer to evaporate silicon atoms for nanoribbon growth. Before using the silicon wafer as the evaporation source, it was first degassed to ensure no impurities entered during the formal experiment. After adjustment, silicon atoms were evaporated. The silicon atom deposition time was 16 minutes at room temperature. After deposition, the wafer was annealed at 473K for 16 minutes. The characterization results under low-temperature scanning tunneling microscopy are as follows: Figure 2 As shown, the silicon nanoribbon structure can be seen.
[0044] Step S3. Tellurium atom deposition
[0045] Using a tellurium source and elemental Te with a purity of 99.99% as the precursor, deposition was performed in a high-temperature evaporation source. Before deposition, degassing was performed. After degassing, the material in the crucible was heated to the evaporation temperature, and the evaporation source was simultaneously turned on to initiate epitaxial growth. The deposition temperature was 462 K, and the deposition time was 10 min. After sample growth was complete, the evaporation source baffle was closed, and the evaporation source control system was shut down. The characterization results using a low-temperature scanning tunneling microscope are as follows: Figure 3 As shown in the scanning tunneling microscope image after tellurium atoms are deposited on silicon nanoribbons, a silicon-tellurium heterostructure can be observed.
[0046] Comparative Example 1
[0047] The difference between this comparative example and Example 1 is that the tellurium atom deposition time is 2 min, as shown in Figure 4(a).
[0048] Comparative Example 2
[0049] The difference between this comparative example and Example 1 is that the deposition time of tellurium atoms is 4 min, as shown in Figure 4(b).
[0050] Comparative Example 3
[0051] The difference between this comparative example and Example 1 is that the tellurium atom deposition time is 8 min, as shown in Figure 4(c).
[0052] observe Figure 4(a)-Figure 4(b) It can be seen that under low coverage, free tellurium atoms and short tellurium chains are the main components; as the tellurium atom coverage increases, the free tellurium atoms and short tellurium chain structure will gradually transform into a one-dimensional ordered tellurium chain structure and silicon-tellurium heterojunction.
[0053] Comparative Example 4
[0054] The difference between this comparative example and Example 1 is that the silicon atom deposition time in this comparative example is 2 minutes, and no tellurium atoms are deposited in this comparative example. The specific operation is as follows:
[0055] Step S1. Metal substrate processing
[0056] After the Ag(110) substrate is transferred to the sample stage, the position of the sample stage in the prep chamber is adjusted up, down, left, right, forward, and backward so that the Ag(110) substrate and the argon ion gun are at the same horizontal level. Then, the mechanical displacement stage is rotated so that the Ag(110) substrate is directly facing the argon ion gun. The micro-leak valve of the argon ion gun is adjusted to release argon gas. At this time, the argon gas pressure is maintained at 1.2 × 10⁻⁶. -5mbar; the argon ion sputtering parameters were adjusted via the argon ion gun control system: emission current 6mA, accelerating voltage 1kV, sputtering time 30min, and beam current I. flax The current was 10.49 A. After argon ion sputtering, the Ag(110) substrate was annealed for surface reconstruction. The sample was preheated by adjusting the current of the DC regulated power supply, and then its current and voltage parameters were slowly adjusted to 1.4 A and 14.7 V. At this time, the sample temperature slowly increased to about 550 °C. After 16 minutes, the sample temperature reached 690-695 °C. Then the current of the DC regulated power supply was slowly reduced to 0.
[0057] After the first treatment, the impurities on the Ag(110) substrate surface were mostly removed, but a small amount of impurities remained. Furthermore, the Ag(110) surface was not yet smooth enough, so a second surface treatment was required. The parameters for the second treatment were the same as the first, with the main purpose of making the Ag(110) substrate surface smoother and the individual mesa larger. A third treatment was then performed, with the same parameters as the first. After this treatment, the individual mesa of the Ag(110) substrate became even larger. After multiple treatments, a clean Ag(110) substrate was obtained.
[0058] Step S2. Silicon Atom Deposition
[0059] After processing the Ag(110) substrate in the prep chamber, the substrate is transferred to the MBE chamber for silicon nanoribbon growth. Highly ordered silicon nanoribbons are grown using molecular beam epitaxy. A self-made, simple silicon wafer evaporation source is used, with the silicon wafer measuring 10mm × 3mm and having a purity of 99.99%. A DC regulated power supply is used to apply current (5.2A, 7.0V) to the silicon wafer to evaporate silicon atoms for nanoribbon growth. Before using the silicon wafer evaporation source, it is first degassed to ensure no impurities enter during the actual experiment. After adjustment, silicon atoms are evaporated. The deposition time is 8 minutes at room temperature. After deposition, the substrate is annealed at 473K for 16 minutes.
[0060] like Figure 5 The image shows a scanning tunneling microscope image of short-chain silicon nanoribbons. The grown sample mainly consists of single-chain silicon nanoribbons with relatively large distances between them.
[0061] Comparative Example 5
[0062] The difference between this comparative example and Example 1 is that the silicon atom deposition time in this comparative example is 8 minutes, and no tellurium atoms are deposited in this comparative example. The specific operation is as follows:
[0063] Step S1. Metal substrate processing
[0064] After the Ag(110) substrate is transferred to the sample stage, the position of the sample stage in the prep chamber is adjusted up, down, left, right, forward, and backward so that the Ag(110) substrate and the argon ion gun are at the same horizontal level. Then, the mechanical displacement stage is rotated so that the Ag(110) substrate is directly facing the argon ion gun. The micro-leak valve of the argon ion gun is adjusted to release argon gas. At this time, the argon gas pressure is maintained at 1.2 × 10⁻⁶. -5 mbar; the argon ion sputtering parameters were adjusted via the argon ion gun control system: emission current 6mA, accelerating voltage 1kV, sputtering time 30min, and beam current I. flax The current was 10.49 A. After argon ion sputtering, the Ag(110) substrate was annealed for surface reconstruction. The sample was preheated by adjusting the current of the DC regulated power supply, and then its current and voltage parameters were slowly adjusted to 1.4 A and 14.7 V. At this time, the sample temperature slowly increased to about 550 °C. After 16 minutes, the sample temperature reached 690-695 °C. Then the current of the DC regulated power supply was slowly reduced to 0.
[0065] After the first treatment, the impurities on the Ag(110) substrate surface were mostly removed, but a small amount of impurities remained. Furthermore, the Ag(110) surface was not yet smooth enough, so a second surface treatment was required. The parameters for the second treatment were the same as the first, with the main purpose of making the Ag(110) substrate surface smoother and the individual mesa larger. A third treatment was then performed, with the same parameters as the first. After this treatment, the individual mesa of the Ag(110) substrate became even larger. After multiple treatments, a clean Ag(110) substrate was obtained.
[0066] Step S2. Silicon Atom Deposition
[0067] After processing the Ag(110) substrate in the prep chamber, the substrate is transferred to the MBE chamber for silicon nanoribbon growth. Highly ordered silicon nanoribbons are grown using molecular beam epitaxy. A silicon wafer with dimensions of 10mm × 3mm and a purity of 99.99% is used as the evaporation source. A DC regulated power supply is used to apply current (5.2A, 7.0V) to the silicon wafer to evaporate silicon atoms for nanoribbon growth. Before using the silicon wafer as the evaporation source, it is first degassed to ensure no impurities enter during the actual experiment. After adjustment, silicon atoms are evaporated. The silicon atom deposition time is 8 minutes at room temperature. After deposition, the wafer is annealed at 473K for 8 minutes.
[0068] Figure 6(a) shows a scanning tunneling microscope image of single-chain silicon nanoribbons, and Figure 6(b) shows a schematic diagram of the width of single-chain silicon nanoribbons. It can be seen from the figures that the grown sample is mainly composed of single-chain silicon nanoribbons, and the distance between the single-chain silicon nanoribbons is relatively large, with each single-chain nanoribbon being approximately 0.8 nm.
[0069] As can be seen from Comparative Examples 4 and 5, due to the short deposition time of silicon and the large distance between the nanoribbons, it may be impossible to form a silicon-tellurium heterostructure with tellurium atoms subsequently.
[0070] Comparative Example 6
[0071] The difference between this comparative example and Example 1 is that the deposition time for silicon atoms in this comparative example is 8 minutes, and the deposition time for tellurium atoms is 8 minutes. The specific operation is as follows:
[0072] Step S1. Metal substrate processing
[0073] After the Ag(110) substrate is transferred to the sample stage, the position of the sample stage in the prep chamber is adjusted up, down, left, right, forward, and backward so that the Ag(110) substrate and the argon ion gun are at the same horizontal level. Then, the mechanical displacement stage is rotated so that the Ag(110) substrate is directly facing the argon ion gun. The micro-leak valve of the argon ion gun is adjusted to release argon gas. At this time, the argon gas pressure is maintained at 1.2 × 10⁻⁶. -5 mbar; the argon ion sputtering parameters were adjusted via the argon ion gun control system: emission current 6mA, accelerating voltage 1kV, sputtering time 30min, and beam current I. flax The current was 10.49 A. After argon ion sputtering, the Ag(110) substrate was annealed for surface reconstruction. The sample was preheated by adjusting the current of the DC regulated power supply, and then its current and voltage parameters were slowly adjusted to 1.4 A and 14.7 V. At this time, the sample temperature slowly increased to about 550 °C. After 16 minutes, the sample temperature reached 690-695 °C. Then the current of the DC regulated power supply was slowly reduced to 0.
[0074] After the first treatment, the impurities on the Ag(110) substrate surface were mostly removed, but a small amount of impurities remained. Furthermore, the Ag(110) surface was not yet smooth enough, so a second surface treatment was required. The parameters for the second treatment were the same as the first, with the main purpose of making the Ag(110) substrate surface smoother and the individual mesa larger. A third treatment was then performed, with the same parameters as the first. After this treatment, the individual mesa of the Ag(110) substrate became even larger. After multiple treatments, a clean Ag(110) substrate was obtained.
[0075] Step S2. Silicon Atom Deposition
[0076] After processing the Ag(110) substrate in the prep chamber, the substrate is transferred to the MBE chamber for silicon nanoribbon growth. Highly ordered silicon nanoribbons are grown using molecular beam epitaxy. A silicon wafer with dimensions of 10mm × 3mm and a purity of 99.99% is used as the evaporation source. A DC regulated power supply is used to apply current (5.2A, 7.0V) to the silicon wafer to evaporate silicon atoms for nanoribbon growth. Before using the silicon wafer as the evaporation source, it is first degassed to ensure no impurities enter during the actual experiment. After adjustment, silicon atoms are evaporated. The silicon atom deposition time is 8 minutes at room temperature. After deposition, the wafer is annealed at 473K for 8 minutes.
[0077] Step S3. Tellurium atom deposition
[0078] Using a tellurium source with elemental Te as the precursor and a purity of 99.99%, deposition was carried out in a high-temperature evaporation source. Before use, the material was first degassed. After degassed, the material in the crucible was heated to the evaporation temperature, and the crucible evaporation source was turned on to start epitaxial growth. The deposition temperature was 462 K and the deposition time was 10 min. After the sample growth was completed, the evaporation source baffle was closed and the control system of the evaporation source was turned off.
[0079] like Figure 7 The scanning tunneling microscopy image shows the growth of tellurium atoms on silicon nanoribbons with low coverage. It can be seen that due to the short silicon deposition time, it is difficult to form a silicon-tellurium heterojunction.
[0080] Comparative Example 7
[0081] The difference between this comparative example and Example 1 is that the silicon atom deposition time in this comparative example is 25 minutes, and no tellurium atoms are deposited, as detailed below:
[0082] Step S1. Metal substrate processing
[0083] After the Ag(110) substrate is transferred to the sample stage, the position of the sample stage in the prep chamber is adjusted up, down, left, right, forward, and backward so that the Ag(110) substrate and the argon ion gun are at the same horizontal level. Then, the mechanical displacement stage is rotated so that the Ag(110) substrate is directly facing the argon ion gun. The micro-leak valve of the argon ion gun is adjusted to release argon gas. At this time, the argon gas pressure is maintained at 1.2 × 10⁻⁶. -5 mbar; the argon ion sputtering parameters were adjusted via the argon ion gun control system: emission current 6mA, accelerating voltage 1kV, sputtering time 30min, and beam current I. flaxThe current was 10.49 A. After argon ion sputtering, the Ag(110) substrate was annealed for surface reconstruction. The sample was preheated by adjusting the current of the DC regulated power supply, and then its current and voltage parameters were slowly adjusted to 1.4 A and 14.7 V. At this time, the sample temperature slowly increased to about 550 °C. After 16 minutes, the sample temperature reached 690-695 °C. Then the current of the DC regulated power supply was slowly reduced to 0.
[0084] After the first treatment, the impurities on the Ag(110) substrate surface were mostly removed, but a small amount of impurities remained. Furthermore, the Ag(110) surface was not yet smooth enough, so a second surface treatment was required. The parameters for the second treatment were the same as the first, with the main purpose of making the Ag(110) substrate surface smoother and the individual mesa larger. A third treatment was then performed, with the same parameters as the first. After this treatment, the individual mesa of the Ag(110) substrate became larger. After multiple treatments, a clean Ag(110) substrate was obtained.
[0085] Step S2. Silicon Atom Deposition
[0086] After processing the Ag(110) substrate in the prep chamber, the substrate is transferred to the MBE chamber for silicon nanoribbon growth. Highly ordered silicon nanoribbons are grown using molecular beam epitaxy. A self-made, simple silicon wafer evaporation source is used, with the silicon wafer measuring 10mm × 3mm and having a purity of 99.99%. A DC regulated power supply is used to apply current (5.2A, 7.0V) to the silicon wafer to evaporate silicon atoms for nanoribbon growth. Before using the silicon wafer evaporation source, it is first degassed to ensure no impurities enter during the actual experiment. After adjustment, silicon atoms are evaporated. The silicon atom deposition time is 25 minutes at room temperature. After deposition, the substrate is annealed at 473K for 25 minutes.
[0087] like Figure 8 The image shows a scanning tunneling microscope image. It can be seen from the image that the grown sample covers the entire platform, and dumbbell-shaped silicene structures continue to grow on top of the first layer.
[0088] Through comparison, it was found that the sample can only be successfully prepared using the technical solution provided in this application. If the process requirements of this application are not followed, the various properties and morphology of the final product will be adversely affected to a certain extent.
[0089] The above description is merely a preferred embodiment of this application and is not intended to limit this application in any way. Although this application has been disclosed above with reference to preferred embodiments, it is not intended to limit this application. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the technical solution of this application. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.
Claims
1. A method for preparing a silicon-tellurium heterojunction based on molecular beam epitaxy, characterized in that, Includes the following steps: Step S1. Perform argon ion etching and annealing on the metal substrate sequentially; Step S2. Silicon nanoribbons are obtained by depositing silicon atoms on the surface of the metal substrate for 16 min, followed by annealing. Step S3. Deposit tellurium atoms on the surface of silicon nanoribbons using molecular beam epitaxy to obtain a silicon-tellurium heterojunction. The deposition time is 10 min.
2. The method for preparing a silicon-tellurium heterojunction based on molecular beam epitaxy according to claim 1, characterized in that, The metal substrate is an Ag metal substrate.
3. The method for preparing a silicon-tellurium heterojunction based on molecular beam epitaxy according to claim 2, characterized in that, The Ag metal substrate is an Ag(110) single crystal.
4. The method for preparing a silicon-tellurium heterojunction based on molecular beam epitaxy according to claim 1, characterized in that, In step S1, the argon gas pressure is controlled to be 1.2 × 10⁻⁶ during argon ion etching. -5 mbar, etching time 25-30 min, beam current I flax The current is 10.49A; the annealing process involves adjusting the current and voltage parameters to 1.4A and 14.7V for 16 minutes.
5. The method for preparing a silicon-tellurium heterojunction based on molecular beam epitaxy according to claim 1, characterized in that, In step S2, when depositing silicon atoms, the deposition current is 5.4A and the voltage is 8.1V. After deposition, the silicon atoms are annealed at 473K for 16 minutes.
6. The method for preparing a silicon-tellurium heterojunction based on molecular beam epitaxy according to claim 1, characterized in that, In step S3, the deposition temperature for tellurium atoms is 462K.
7. The method for preparing a silicon-tellurium heterojunction based on molecular beam epitaxy according to claim 1, characterized in that, The silicon wafer used for depositing silicon atoms has a purity of 99.99%.
8. The method for preparing a silicon-tellurium heterojunction based on molecular beam epitaxy according to claim 1, characterized in that, The purity of the tellurium source used for depositing tellurium atoms is 99.99%.