Two-dimensional strain superlattice material and preparation method and application thereof

Abstract

The invention discloses a two-dimensional strain superlattice material and a preparation method and application thereof, and belongs to the technical field of two-dimensional semiconductor material preparation. The invention discloses a method for preparing a two-dimensional strain superlattice material. The method comprises the following steps: S1, carrying out heat treatment on a single crystal aluminum oxide substrate in an air atmosphere, and then carrying out heat treatment in a sulfur steam atmosphere to obtain a surface structure with sulfur passivation; and S2, a transition metal element source and a non-metal source are subjected to chemical vapor deposition on the nano-structure substrate in a protective gas atmosphere to form a thin film, and then the thin film is transferred to the substrate to obtain the two-dimensional strain superlattice material with the nano periodic folds. The invention provides a method for growing a high-quality two-dimensional strain superlattice material by using a single crystal aluminum oxide substrate with a nano-structure surface, a nano-structure is formed by heat treatment of the single crystal aluminum oxide substrate, and a chemical vapor deposition reaction is carried out on the substrate with transition metal and a non-metal source in the atmosphere of protective gas. Therefore, the high-quality two-dimensional strain superlattice material can be obtained.

Description

Technical Field

[0001] This invention relates to the field of two-dimensional semiconductor material preparation technology, and in particular to a two-dimensional strained superlattice material, its preparation method, and its applications. Background Technology

[0002] Two-dimensional superlattices, as an important component of two-dimensional material systems, exhibit exotic physical properties beyond intrinsic materials by introducing periodic structural modulations (such as composition, strain, and moiré periods), opening new avenues for next-generation optoelectronics, quantum devices, and energy applications. Among them, strain-induced superlattices have attracted much attention due to their unique physical mechanisms. Unlike compositional superlattices that rely on the stacking of heterogeneous materials, strain-induced superlattices introduce periodic, nanoscale strain fields into single or homogeneous two-dimensional materials, achieving precise control over band structure, symmetry, and carrier transport behavior. This control stems from the pseudomagnetic field generated by the strain gradient, valley polarization effects, and localized quantum confinement, which can induce novel phenomena such as significantly enhanced photothermal and electrical responses and topological phase transitions, providing a unique platform for exploring fundamental physics and developing high-performance devices.

[0003] While two-dimensional strained superlattices hold immense potential, their controllable fabrication remains a significant challenge. Current mainstream fabrication methods, such as pre-stretched flexible substrates, structured substrates, and lattice or thermal expansion mismatches, generally suffer from poor scalability, insufficient uniformity, and limited precision. These methods typically only produce micrometer-scale periodic strain units, making it difficult to develop nanoscale quantum effects. They are also accompanied by issues such as poor crystal quality, random orientation, or small sample sizes (typically only tens of micrometers). For example, the pre-stretched PDMS method relies on mechanically exfoliated sheets, severely limiting sample size; while the structured substrate transfer method requires complex micro / nano fabrication or specific substrates, hindering large-area fabrication. Although lattice mismatch and thermal shrinkage methods each have their advantages, the former leads to inconsistent strain patterns, while the latter is limited by material-substrate interactions and defect formation. These technological bottlenecks make the fabrication of controllable nanometer-scale periodicity, large-area, and highly ordered two-dimensional strained structures extremely challenging, severely restricting the large-scale fabrication and application of strained superlattices.

[0004] In summary, many challenges remain in the fabrication of high-quality two-dimensional strained superlattice materials. Researchers need to further improve the controllability, reproducibility, and versatility of the fabrication process, as well as the uniformity and crystal quality of the prepared transition metal chalcogenide thin films, thereby enhancing the performance and reliability of devices. To address these issues, this invention proposes a two-dimensional strained superlattice material and its wafer fabrication method, effectively solving the aforementioned problems. Summary of the Invention

[0005] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention proposes a two-dimensional strained superlattice material, its preparation method, and its applications. This invention provides a method for growing high-quality two-dimensional strained superlattice materials using a single-crystal alumina substrate with a nanostructured surface. This method involves forming a nanostructure on a heat-treated single-crystal alumina substrate, followed by chemical vapor deposition of the nanostructure with transition metal and non-metal sources on the substrate under a protective gas atmosphere, thereby obtaining high-quality two-dimensional strained superlattice materials.

[0006] The present invention also provides a two-dimensional strained superlattice material obtained by the above preparation method.

[0007] This invention also provides the application of the above-described preparation method in the preparation of electronic devices and optoelectronic devices.

[0008] According to a first aspect of the present invention, a method for preparing a two-dimensional strained superlattice material is provided, comprising the following steps:

[0009] S1. A single-crystal alumina substrate is first heat-treated in an air atmosphere and then heat-treated in a sulfur vapor atmosphere to obtain an alumina substrate with a sulfur passivation structure.

[0010] S2. A thin film is formed by chemical vapor deposition of a transition metal source and a non-metal source on an alumina substrate with a sulfur passivation structure under a protective gas atmosphere. The thin film is then transferred to a flat substrate to obtain a two-dimensional strained superlattice material with nano-periodic folds.

[0011] This invention proposes a method for preparing two-dimensional strained superlattice materials. Through surface modification of a single-crystal alumina substrate and chemical vapor deposition (CVD), high-quality, large-area, nano-periodic folded two-dimensional strained superlattice materials are prepared. The core of this method lies in utilizing the nano-zigzag structure of the substrate to induce thin film growth, introducing a periodic strain field, and modulating the material's physical properties. Specifically, it consists of the following key steps:

[0012] 1. A single-crystal alumina substrate with a (1-100) plane is heat-treated at high temperature in an air atmosphere, followed by heat treatment in a sulfur vapor atmosphere to form a nano-serrated surface with a sulfur passivation structure. High-temperature heat treatment promotes surface atomic reconstruction, forming a nanoscale serrated morphology; sulfur vapor treatment partially passivates oxygen atoms through sulfur atoms, and high-temperature heat treatment induces surface atomic reconstruction, forming high-level steps and nanoscale periodic structures; sulfur passivation enhances surface chemical activity, stabilizes the serrated morphology, provides preferential two-dimensional growth sites for subsequent metal sources, reduces the stacking tendency of materials in the vertical direction, and promotes the formation of ultrathin structures.

[0013] 2. Under a protective gas atmosphere, thin films are deposited on a modified substrate using transition metal source materials and non-metal source materials via CVD reaction. The films are then transferred to a flat substrate. The serrated surface and high-level steps of the modified substrate guide the epitaxial growth of the precursor along a two-dimensional direction. The strain field and chemically active sites at the step edges promote uniform monolayer deposition. Sulfur modification, through the regulation of surface structure and chemical properties, provides a uniform growth template, ensuring the formation of monolayers or ultrathin films.

[0014] In summary, this invention ingeniously achieves the fabrication of two-dimensional strained superlattices through substrate nanostructuring and CVD processes. In principle, it utilizes surface modification and strain-induced mechanisms, overcoming the limitations of traditional methods. Its beneficial effects are reflected in the fabrication of high-quality, large-area materials, performance optimization, and process simplicity, providing technical support for the large-scale application of electronic and optoelectronic devices.

[0015] According to some embodiments of the present invention, in step S1, the temperature for heat treatment in the air atmosphere is 1400-1600°C, and the heat treatment time is 1-6 hours.

[0016] Under the above conditions, the atoms on the surface of single-crystal alumina will undergo sufficient migration and rearrangement to form regular nanosteps and serrated structures, providing a stable template for subsequent strained superlattices and facilitating the subsequent sulfur passivation reaction, thus giving the serrated surface higher chemical activity.

[0017] According to some embodiments of the present invention, in step S1, the specific process parameters for heat treatment under air atmosphere can be, for example, the heat treatment temperature is about 1400°C, about 1450°C, about 1500°C, about 1550°C or about 1600°C, and the corresponding time is about 1h, about 2h, about 3h, about 4h or about 6h.

[0018] According to some embodiments of the present invention, in step S1, the temperature of the heat treatment under the sulfur vapor atmosphere is 700-800°C, the heat treatment time is 10-60 min, and the flow rate of the sulfur vapor is 50-100 sccm.

[0019] Under the above conditions, it is ensured that sulfur atoms can effectively passivate some oxygen atoms on the surface of alumina to form a sulfur passivation structure, while avoiding excessive temperature that could cause the substrate structure to collapse or the surface to become rough. This allows the sulfur passivation reaction to proceed fully, forming a stable serrated surface, while also preventing excessive reaction or increased defects caused by prolonged processing.

[0020] According to some embodiments of the present invention, in step S1, the specific process parameters for heat treatment under the sulfur vapor atmosphere may be, for example, the heat treatment temperature is about 700°C, about 750°C or about 800°C, and the corresponding time is about 10 min, about 30 min or about 60 min, while the flow rate of sulfur vapor is about 50 sccm, about 75 sccm, about 80 sccm or about 100 sccm.

[0021] According to some embodiments of the present invention, the transition metal source includes at least one of a molybdenum source and a tungsten source.

[0022] According to some embodiments of the present invention, the non-metallic source includes at least one of a sulfur source and a selenium source.

[0023] According to some embodiments of the present invention, step S2 further includes adding a catalyst.

[0024] According to some embodiments of the present invention, step S2 includes: forming a thin film by chemical vapor deposition of a transition metal element source, a catalyst and a non-metal source on a nanostructure substrate under a protective gas atmosphere, and then transferring the thin film to a flat substrate to obtain a two-dimensional strained superlattice material with nano-periodic wrinkles.

[0025] According to some embodiments of the present invention, the catalyst comprises sodium bromide.

[0026] On the one hand, sodium bromide can lower the sublimation and reaction energy barriers of transition metal sources, accelerate the reaction rate, and ensure effective deposition at lower temperatures. On the other hand, its presence can improve the nucleation process, reduce random nucleation and defect generation, thereby significantly improving the crystal quality and uniformity of the film. Through the catalytic effect of sodium bromide, the obtained two-dimensional strained superlattice not only has a larger domain size and higher continuity, but is also more conducive to large-area fabrication, laying the material foundation for subsequent electronic and optoelectronic device applications.

[0027] According to some embodiments of the present invention, in step S2, the protective gas is at least one of nitrogen and argon.

[0028] According to some embodiments of the present invention, in step S2, the rate of introduction of the protective gas is 1 to 1000 sccm.

[0029] According to some embodiments of the present invention, in step S2, the rate at which the protective gas is introduced may be, for example, about 10 sccm, about 100 sccm, about 200 sccm or about 1000 sccm.

[0030] According to some embodiments of the present invention, in step S2, the rate of introduction of the protective gas is 10 to 200 sccm.

[0031] According to some embodiments of the present invention, in step S2, the temperature of the chemical vapor deposition reaction is 600-1000°C; the heating rate of the chemical vapor deposition reaction is 10-60°C / min; and the holding time of the chemical vapor deposition reaction is 0-60min.

[0032] According to some embodiments of the present invention, in step S2, the temperature of the chemical vapor deposition reaction is 850-950°C; the heating rate of the chemical vapor deposition reaction is 30-40°C / min; and the holding time of the chemical vapor deposition reaction is 3-10 min.

[0033] According to some embodiments of the present invention, the chemical vapor deposition reaction is naturally cooled to room temperature under a protective gas atmosphere.

[0034] According to some embodiments of the present invention, in step S2, the chemical vapor deposition reaction is carried out at 760 Torr.

[0035] According to some embodiments of the present invention, in step S2, the transfer medium is a toluene solution of polystyrene with a concentration of 0.08 to 0.15 g / mL, and the spin-coating speed of the transfer medium on the film surface is 1000 to 3000 rpm.

[0036] According to some embodiments of the present invention, in step S2, the concentration of the toluene solution of polystyrene is 0.15 g / mL; the spin-coating speed of the transfer medium on the film surface is 3000 rpm.

[0037] According to a second aspect of the present invention, a two-dimensional strained superlattice material is provided, which is prepared by a preparation method.

[0038] According to a third aspect of the present invention, the application of the aforementioned preparation method in the preparation of electronic devices and optoelectronic devices is provided.

[0039] Since the application adopts all the technical solutions of the modified cathode material of the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments.

[0040] Unless otherwise specified, the term "about" in this invention actually means that the error is allowed to be within ±2%, for example, about 100 is actually 100 ± 2% × 100.

[0041] Unless otherwise specified, "between" in this invention includes the number itself, for example, "between 2 and 3" includes the endpoint values ​​2 and 3.

[0042] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. Attached Figure Description

[0043] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0044] Figure 1 This is a schematic diagram of the preparation method of a two-dimensional strained superlattice.

[0045] Figure 2 These are atomic force microscope images of the surface of single-crystal alumina before and after pretreatment obtained in Example 1 of the present invention.

[0046] Figure 3 This is an optical microscope image of the monolayer molybdenum disulfide prepared in Example 1 of the present invention on a single-crystal alumina substrate.

[0047] Figure 4 The image shows the Raman spectrum of the monolayer molybdenum disulfide prepared in Example 1 of this invention under a 532 nm laser.

[0048] Figure 5 The photoluminescence spectrum of the monolayer molybdenum disulfide prepared in Example 1 of this invention under a 532nm laser.

[0049] Figure 6 This is an optical microscope image of the wafer-level monolayer molybdenum disulfide material prepared in Example 1 of the present invention transferred onto a silicon wafer.

[0050] Figure 7 This is a cross-sectional transmission electron microscope image of the molybdenum disulfide strained superlattice prepared in Example 1 of the present invention.

[0051] Figure 8 This is an optical microscope image of tungsten disulfide prepared in Example 2 of the present invention on a single-crystal alumina substrate.

[0052] Figure 9 This is an optical microscope image of tungsten diselenide prepared in Example 3 of the present invention on a single-crystal alumina substrate.

[0053] Figure 10 This is a cross-sectional transmission electron microscope image of molybdenum disulfide prepared in Comparative Example 1 transferred to the surface of a silicon wafer.

[0054] Figure 11 This is a schematic diagram of the transmission electron microscope cross-section of the molybdenum disulfide prepared in Comparative Example 1 after it has been transferred to a silicon wafer.

[0055] Figure 12 This is a schematic diagram of the transmission electron microscope cross-section of the molybdenum disulfide prepared in Comparative Example 1 after it has been transferred to a silicon wafer. Detailed Implementation

[0056] The following will describe the concept and technical effects of the present invention clearly and completely with reference to embodiments, so as to fully understand the purpose, features and effects of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the scope of protection of the present invention.

[0057] In the description of this invention, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0058] Example 1

[0059] This embodiment provides a molybdenum disulfide strained superlattice and its preparation method. A schematic diagram of the preparation method is shown below. Figure 1 As shown, the preparation method includes the following steps:

[0060] S1.1: The (1-100) single crystal alumina substrate (m-plane sapphire substrate) is placed in a high-temperature muffle furnace and heat-treated at 1600℃ for 6 hours, followed by heat treatment in a sulfur vapor atmosphere for 60 minutes to obtain a serrated alumina substrate with a sulfur passivation structure surface.

[0061] S2.1: Take 200 mg of sulfur powder (non-metallic source) and place it in an alumina boat. Place the alumina boat in the first heating zone of a tube furnace. After purging the air in the tube furnace by introducing 100 sccm of argon gas for 20 minutes, heat the first heating zone to 150°C at a rate of 40°C / min to melt and volatilize the sulfur powder. Take a mixture of 3 mg of molybdenum trioxide and sodium bromide as a transition metal source and place it in another alumina boat, wherein the mass ratio of tungsten trioxide and sodium bromide is 1:1. Place the single crystal alumina (serrated alumina substrate with sulfur passivation structure surface) obtained in S1.1 face down above the transition metal source of the alumina boat. Place the alumina boat in the second heating zone downstream of the first heating zone of the tube furnace.

[0062] S2.2: After purging the air in the tube furnace with 100 sccm of argon gas for 10 minutes, the first heating zone is heated to 150°C at a rate of 40°C / min (with a continuous and stable supply of sulfur vapor), and the second heating zone is heated to 850°C. After holding at this temperature for 10 minutes, the heating is stopped, allowing molybdenum trioxide to sublimate and react with sulfur vapor, thus growing a molybdenum disulfide film on the pretreated single-crystal alumina substrate. The film is then allowed to cool naturally to room temperature.

[0063] S2.3: A polystyrene (PS) toluene solution with a concentration of 0.15 g / mL was coated onto a molybdenum disulfide / monocrystalline alumina substrate by spin coating at a speed of 3,000 rpm for 1 min. The substrate was then placed in air and baked at 80 °C for 15 min to ensure complete solvent evaporation and to obtain a uniform and adherent PS layer. The monocrystalline alumina substrate was then separated by deionized water, and the PS / molybdenum disulfide layer was transferred onto a silicon wafer. Finally, the PS layer was dissolved in toluene, leaving a complete two-dimensional strained superlattice film on the silicon wafer substrate.

[0064] Figure 2 In the figure, a and b are atomic force microscopy images of the surface morphology of single-crystal alumina before and after high-temperature heat treatment in step S1.1 of Embodiment 1 of the present invention; Figure 3 This is an optical microscope image of the molybdenum disulfide monolayer material prepared in Example 1 of the present invention. The domain size of the obtained tungsten disulfide monolayer material is 30-50 μm. Figure 4 The image shows the Raman spectrum of the molybdenum disulfide material prepared in Example 1 of this invention under a 532nm laser, indicating that the obtained material is a single-layer material. Figure 5 The photoluminescence spectrum of the molybdenum disulfide monolayer material prepared in Example 1 of this invention under a 532nm laser has a full width at half maximum (FWHM) of 51meV, indicating that the sulfur defect concentration of the material is very low. Figure 6 In the image, 'a' is a scanning electron microscope (SEM) image of molybdenum disulfide transferred to the surface of a silicon wafer. Figure 6 In the image, b is a cross-sectional transmission electron microscope image. The obtained strain superlattice is composed of periodic folded strain units with a strain period of approximately 20 nm.

[0065] Example 2:

[0066] This embodiment provides a method for preparing a wafer-level molybdenum disulfide strained superlattice. The only difference between this method and that of Embodiment 1 is that a 2-inch single-crystal alumina substrate is used in step S2.1, and heating is stopped after holding the temperature for 30 minutes in step S2.2. The rest are the same as in Embodiment 1.

[0067] Figure 7 This is a light micrograph of molybdenum disulfide prepared in Example 2 of the present invention, showing that by extending the reaction time, the island-like crystal domains expand to form a continuous thin film. Figure 8The image shows the transfer of a 2-inch molybdenum disulfide thin film onto the surface of a 4-inch silicon wafer, demonstrating that this method is suitable for the fabrication of large-area strained superlattices.

[0068] Example 3:

[0069] This embodiment provides a tungsten disulfide thin film material and its preparation method. The only difference between the transition metal sulfide film and that in Example 1 is that in step S2.1, a mixture of 5 mg of tungsten trioxide and sodium bromide is used as a transition metal source and placed in another corundum boat, wherein the mass ratio of tungsten trioxide to sodium bromide is 3:1. In step S2.2, the second heating zone is heated to 950°C at a rate of 40°C / min. The rest is the same as in Example 1.

[0070] Figure 9 This is an optical microscope image of tungsten disulfide prepared in Example 3 of the present invention. The prepared material has a good morphology, is arranged in the same direction, and has a crystal domain size of 30-130 μm.

[0071] Example 4:

[0072] This embodiment provides a wafer-level (4-inch) tungsten disulfide thin film material and its preparation method. The only difference between the process and that in Embodiment 3 is that heating is stopped after holding the temperature for 50 minutes in step S2.2. All other steps are the same as in Embodiment 3.

[0073] Figure 10 The image shows a photograph of the 4-inch tungsten disulfide thin film material, indicating that the method is suitable for the preparation of large-area tungsten disulfide materials.

[0074] Example 5:

[0075] This embodiment provides a tungsten diselenide strained superlattice material and its preparation method. The difference between the transition metal sulfide film and that in Example 1 is that in step S2.1, 200 mg of selenium powder is placed in an alumina boat, which is then placed in the first heating zone of a tube furnace. After purging the air from the tube furnace with 100 sccm of argon gas for 20 minutes, the first heating zone is heated to 250°C at a rate of 40°C / min to melt and volatilize the selenium powder. Then, a mixture of 5 mg of tungsten trioxide and sodium bromide is placed in another alumina boat as a transition metal source, wherein the mass ratio of tungsten trioxide to sodium bromide is 3:1. In step S2.2, the second heating zone is heated to 950°C at a rate of 40°C / min. The rest is the same as in Example 1.

[0076] Figure 11 This is an optical microscope image of the tungsten diselenide material prepared in Example 4 of the present invention. The prepared material has a good morphology, is arranged in the same direction, and has a crystal domain size of 30-80 μm.

[0077] Comparative Example 1

[0078] This comparative example provides a molybdenum disulfide thin film material. The only difference between the film and Example 1 is that the single-crystal alumina substrate in step S1.1 was not pretreated. All other aspects are the same as in Example 1.

[0079] Figure 12 This is a schematic cross-section of a transmission electron microscope (TEM) image of the molybdenum disulfide prepared in Comparative Example 1 after it has been transferred to a silicon wafer. Compared to Example 1, Comparative Example 1 exhibits a flat morphology and does not possess a nanoscale periodic strained superlattice structure.

[0080] In summary, this invention employs a method for growing two-dimensional strained superlattice materials on single-crystal alumina with nanostructured surfaces, achieving high-quality strained superlattice fabrication of materials such as molybdenum disulfide and tungsten disulfide. The resulting materials exhibit domain sizes ranging from 30 to 130 μm, continuous film sizes up to 2 inches, and strain periods as low as 20 nm. This type of two-dimensional strained superlattice material, composed of a nano-periodic wrinkled array, shows broad application prospects in fields such as electronic devices.

[0081] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments, and various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features thereof can be combined with each other unless otherwise specified.

Claims

1. A method of making a two-dimensional strained superlattice material, comprising: The method comprises the following steps: S1. obtaining an alumina substrate with a sulfur passivation structure by subjecting a single-crystal alumina substrate to heat treatment in an air atmosphere and then to heat treatment in a sulfur vapor atmosphere; S2. forming a film on the alumina substrate with the sulfur passivation structure by chemical vapor deposition of a transition metal element source and a nonmetal source in a protective gas atmosphere, and then transferring the film to a flat substrate to obtain a two-dimensional strained superlattice material.

2. The method of claim 1, wherein the method further comprises: In step S1, the temperature for heat treatment in the air atmosphere is 1400-1600℃, and the heat treatment time is 1-6h.

3. The method of claim 1, wherein the method further comprises: In step S1, the temperature for heat treatment in the sulfur vapor atmosphere is 700-800℃, the heat treatment time is 10-60min, and the flow rate of the sulfur vapor is 50-100sccm.

4. The method of claim 1, wherein the method further comprises: The transition metal element source comprises at least one of a molybdenum source and a tungsten source.

5. The method of claim 1, wherein the method further comprises: The nonmetal source comprises at least one of a sulfur source and a selenium source.

6. The method of claim 1, wherein the method further comprises: In step S2, the protective gas is at least one of nitrogen and argon.

7. The method of claim 1, wherein the method further comprises: In step S2, the flow rate of the protective gas is 1-1000sccm.

8. The method of claim 1, wherein the method further comprises: The temperature for the chemical vapor deposition reaction is 600-1000℃, the temperature rising rate for the chemical vapor deposition reaction is 10-60℃ / min, and the heat preservation time for the chemical vapor deposition reaction is 0-60min.

9. A two-dimensional strained superlattice material, characterized in that, The two-dimensional strained superlattice material is prepared by the preparation method according to any one of claims 1-8.

10. Use of the preparation method according to any one of claims 1-8 in the preparation of electronic devices and optoelectronic devices.

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