A method for preparing a two-dimensional semiconductor phase platinum diselenide single crystal material

Abstract

The application discloses a kind of preparation methods of two-dimensional semiconductor phase platinum diselenide single crystal material, it is related to nanometer material preparation technical field, and its technical solution points are: the method is based on liquid phase precursor assisted chemical vapor deposition (CVD) preparation high-quality single crystal two-dimensional semiconductor phase PtSe2 Material.The method is through liquid phase precursor accurate control stoichiometric ratio of platinum source and selenium source, further optimize CVD preparation process, realize controllable preparation of high-quality, large-size two-dimensional PtSe2 Single crystal.Specific steps include liquid phase precursor preparation, substrate surface pretreatment, precursor fixation and nucleation, CVD-gas solid reaction and cooling and collection.The method can solve the problems of high reaction temperature, difficult to control stoichiometric ratio, multiple side reactions, limited substrate selection, low yield, poor repeatability and complex process in the prior art, realize controllable preparation of high-quality, large-size PtSe2 Single crystal material, and promote its application in electronic devices, photodetectors and catalysis.

Description

Technical Field

[0001] This invention relates to the field of nanomaterial preparation technology, and more specifically, to a method for preparing a two-dimensional semiconductor phase platinum diselenide single crystal material. Background Technology

[0002] Two-dimensional materials have attracted widespread attention in the field of nanotechnology due to their unique physical, chemical, and electronic properties. Since the discovery of graphene, transition metal dichalcogenides (TMDCs) such as MoS2 and WS2 have become research hotspots due to their excellent semiconductor properties. Platinum diselenide (PtSe2), as an emerging TMDC material, has a layered structure and a tunable band gap, showing great application potential in semiconductor devices, photodetectors, sensors, and catalysis.

[0003] The crystal structure of PtSe2 consists of a layer of platinum atoms sandwiched between two layers of selenium atoms, bound together by van der Waals forces. It can be exfoliated into single-layer or multi-layer two-dimensional materials. Single-layer PtSe2 exhibits direct bandgap characteristics, while multi-layer PtSe2 behaves as an indirect bandgap semiconductor. This tunable bandgap makes it valuable for applications in optoelectronic devices. Furthermore, PtSe2 possesses high carrier mobility, excellent light absorption properties, and good chemical stability, making it considered an ideal material for next-generation high-performance electronic and optoelectronic devices.

[0004] Despite the excellent properties of PtSe2, the controllable preparation of high-quality single-crystal materials still faces many challenges. Currently, the main methods for preparing two-dimensional PtSe2 materials include mechanical exfoliation, chemical vapor deposition (CVD), and liquid-phase synthesis. However, these methods have the following problems in practical applications:

[0005] 1. High reaction temperature and high energy consumption.

[0006] Existing CVD methods for preparing PtSe2 typically require high temperatures (above 600°C), which not only increases energy consumption but may also lead to more material defects and affect crystallization quality.

[0007] 2. Stoichiometry is difficult to control precisely.

[0008] Existing methods often use solid platinum sources (such as platinum foil or platinum salt) and selenium powder as precursors, making it difficult to precisely control the stoichiometric ratio of platinum and selenium sources, resulting in uneven material composition and poor crystallization quality.

[0009] 3. Numerous side reactions and low material purity.

[0010] Liquid precursors (such as platinum salt solutions) used in liquid-phase synthesis are prone to decomposition at high temperatures, producing byproducts that affect the purity and crystallinity of the material.

[0011] 4. Limited substrate selection

[0012] Existing methods often rely on specific substrates (such as metal, mica, or sapphire substrates), which limits the versatility of materials and the flexibility of subsequent device fabrication.

[0013] 5. Low yield, difficult to produce on a large scale

[0014] Although mechanical exfoliation can yield high-quality single-crystal PtSe2, the yield is extremely low and cannot meet the needs of large-scale applications.

[0015] 6. The process is complex and has poor repeatability.

[0016] Existing methods such as molecular beam epitaxy (MBE) and pulsed laser deposition (PLD) are costly, complex, difficult to achieve large-scale preparation, and have poor reproducibility.

[0017] Therefore, it is of great significance to develop a simple, efficient, and large-scale method for preparing high-quality single-crystal two-dimensional semiconductor PtSe2 materials. Summary of the Invention

[0018] The purpose of this invention is to provide a method for preparing two-dimensional semiconductor-phase platinum diselenide single crystal materials, aiming to solve the problems of high reaction temperature, difficulty in controlling stoichiometry, numerous side reactions, limited substrate selection, low yield, and complex processes in existing technologies. This method achieves controllable preparation of high-quality, large-size PtSe2 materials through liquid-phase precursor-assisted CVD, promoting its application in electronic devices, photodetectors, and catalysis.

[0019] The above-mentioned technical objective of the present invention is achieved through the following technical solution: a method for preparing a two-dimensional semiconductor phase platinum diselenide single crystal material, comprising the following steps:

[0020] S1. Preparation of liquid-phase precursors;

[0021] S2. Substrate surface pretreatment;

[0022] S3. Precursor coating;

[0023] S4.CVD - Gas-solid reaction;

[0024] S5. Cooling and Collection.

[0025] The present invention is further configured such that the specific operation for preparing the liquid precursor in S1 is as follows:

[0026] (1) Dissolve platinum salt and selenium source in a solvent to form a homogeneous liquid precursor solution; the solvent includes, but is not limited to, hydrochloric acid solution with a concentration of 0.001-1M, sodium hydroxide solution with a concentration of 0.001-1M, and deionized water; the platinum salt includes, but is not limited to, chloroplatinic acid, platinum chloride, and platinum sulfate.

[0027] (2) The molar ratio of platinum salt to selenium source is 2:1 to 1:4 to ensure precise control of stoichiometry;

[0028] (3) The solution is mixed evenly by stirring and ultrasonic treatment to avoid precipitation or stratification.

[0029] By employing the above technical solution, the stoichiometric ratio of platinum and selenium sources in the liquid-phase precursor can be precisely controlled, ensuring reaction uniformity. A uniform precursor film can be formed on the substrate surface using spin coating or drop coating methods, providing a foundation for the growth of high-quality single-crystal PtSe2.

[0030] The present invention is further configured such that the specific operations of the substrate pretreatment in S2 are as follows:

[0031] (1) Select high-purity silicon wafers, silicon dioxide substrates, or flexible substrates;

[0032] (2) Clean the surface contaminants by ultrasonic cleaning with acetone, isopropanol and deionized water for 10 minutes in sequence;

[0033] (3) Dry the substrate with nitrogen gas to ensure the surface is clean and dry.

[0034] By adopting the above technical solutions and selecting various substrates (such as silicon wafers, silicon dioxide substrates, and flexible substrates), the versatility of materials and the flexibility of device processing are improved.

[0035] The present invention is further configured such that the specific operation of precursor coating in S3 is as follows:

[0036] (1) The liquid precursor solution is uniformly spin-coated onto the substrate surface;

[0037] (2) The thickness of the precursor film is controlled by spin coating or drop coating. The spin coating speed is 2000-4000 rpm and the time is 30-60 seconds.

[0038] (3) After coating, pre-bake the substrate at 80-120℃ for 5-10 minutes to remove the solvent.

[0039] By adopting the above technical solution, the reaction temperature is reduced to 400-550℃, thus reducing material defects and side reactions caused by high temperatures. The low-temperature reaction is beneficial for forming high-quality single-crystal PtSe2, while also reducing energy consumption.

[0040] The present invention is further configured such that the specific operation of the CVD reaction in S4 is as follows:

[0041] (1) The substrate coated with the precursor is placed in a CVD furnace and the reaction is carried out under the protection of an inert gas;

[0042] (2) The reaction temperature is 400-550℃ and the reaction time is 30-90 minutes;

[0043] (3) Selenium vapor is generated by the evaporation of selenium powder at 200-300℃ and is transported to the reaction zone by a carrier gas;

[0044] (4) By controlling the selenium powder evaporation temperature and carrier gas flow rate, the concentration of selenium vapor is adjusted to ensure uniform reaction.

[0045] By adopting the above technical solution, the concentration of selenium vapor can be precisely adjusted by controlling the evaporation temperature of selenium powder and the flow rate of carrier gas, ensuring a sufficient supply of selenium source during the reaction process and avoiding selenium defects.

[0046] The present invention is further configured such that the specific operations of cooling and collection in S5 are as follows:

[0047] (1) After the reaction is complete, turn off the heating system and allow the furnace to cool naturally to room temperature;

[0048] (2) Remove the substrate to obtain a high-quality single-crystal two-dimensional semiconductor phase PtSe2 material;

[0049] (3) The material is characterized by optical microscopy, scanning electron microscopy (SEM) and Raman spectroscopy to ensure its crystal quality and uniformity.

[0050] The present invention is further configured such that: the concentration of platinum salt is 0.01-0.1 mol / L and the concentration of selenium source is 0.02-0.4 mol / L during the preparation of the liquid-phase precursor.

[0051] The present invention is further configured such that: the spin coating speed is preferably 3000 rpm, and the spin coating time is preferably 30 seconds.

[0052] The present invention is further configured such that: the reaction temperature of the CVD reaction is preferably 500°C, the reaction time is preferably 60 minutes, and the selenium powder evaporation temperature is preferably 250°C.

[0053] The present invention is further configured such that the carrier gas flow rate in the CVD reaction is 50-100 sccm.

[0054] In summary, the present invention has the following beneficial effects:

[0055] 1. Low reaction temperature and low energy consumption

[0056] Existing technology: Traditional CVD methods for preparing PtSe2 typically require high temperatures (above 600°C), resulting in high energy consumption and a high risk of material defects.

[0057] This invention utilizes a liquid-phase precursor-assisted CVD method to reduce the reaction temperature to 400-550℃, significantly reducing energy consumption and material defects caused by high temperatures, thereby improving crystallization quality.

[0058] 2. Precise and controllable stoichiometry

[0059] Existing technology: Existing methods mostly use solid platinum sources (such as platinum foil or platinum salt) and selenium powder as precursors, which makes it difficult to accurately control the stoichiometric ratio of platinum and selenium sources, resulting in uneven material composition.

[0060] This invention utilizes liquid-phase precursors (such as chloroplatinic acid and sodium selenosulfate solution) to precisely control the stoichiometric ratio of platinum and selenium sources, ensuring uniform material composition and improving crystallization quality.

[0061] 3. Fewer side reactions and higher material purity

[0062] Existing technology: Liquid precursors used in liquid-phase synthesis are prone to decomposition at high temperatures, producing byproducts that affect the purity and crystallinity of the material.

[0063] This invention aims to reduce side reactions and improve material purity and crystallinity by optimizing the composition and reaction conditions of the liquid-phase precursor.

[0064] 4. Flexible substrate selection and strong versatility

[0065] Existing technologies: Existing methods often rely on specific substrates (such as mica or sapphire), which limits the versatility of materials and the flexibility of subsequent device fabrication.

[0066] This invention is applicable to a variety of substrates (such as silicon wafers, silicon dioxide substrates, and flexible substrates), improving the versatility of materials and the flexibility of device processing.

[0067] 5. Large-area, uniform preparation, high yield

[0068] Existing technologies: Mechanical exfoliation yields extremely low output, while CVD and liquid-phase synthesis methods struggle to achieve large-area uniform preparation.

[0069] This invention enables the preparation of large-area, uniform single-crystal PtSe2 thin films using a liquid-phase precursor-assisted CVD method, thereby increasing yield and meeting the needs of large-scale applications.

[0070] 6. The process is simple and has good repeatability.

[0071] Existing technologies: Existing methods such as molecular beam epitaxy (MBE) and pulsed laser deposition (PLD) are costly, have complex processes, are difficult to achieve large-scale preparation, and have poor reproducibility.

[0072] This invention features a simple process, easily controllable parameters, good repeatability, and suitability for industrial production.

[0073] 7. The material properties are adjustable and it has a wide range of applications.

[0074] Existing technology: Existing methods have difficulty in precisely controlling the number of layers, lattice orientation and semiconductor properties of PtSe2, which limits its application in devices.

[0075] This invention precisely controls the number of layers, lattice orientation, and semiconductor properties of PtSe2 by adjusting the precursor concentration and reaction conditions to meet the application requirements of different devices.

[0076] 8. Environmentally friendly and low-cost

[0077] Existing technologies: Some methods use toxic or expensive chemical reagents, increasing costs and environmental burden.

[0078] This invention employs environmentally friendly liquid-phase precursors and low-temperature CVD processes, reducing costs and environmental burden. Attached Figure Description

[0079] Figure 1 This is a flowchart illustrating the preparation process of CVD-grown PtSe2 single crystal semiconductor material according to the present invention.

[0080] Figure 2 These are optical microscope images of the PtSe2 sample in Embodiment 1 of the present invention;

[0081] Figure 3 This is the Raman spectrum of a typical semiconductor phase PtSe2 in Embodiment 1 of the present invention;

[0082] Figure 4 These are typical optical microscope photographs from Embodiment 2 of the present invention;

[0083] Figure 5 This is the Raman spectrum of PtSe2, a typical semiconductor phase in Embodiment 2 of the present invention. Detailed Implementation

[0084] The following is in conjunction with the appendix Figure 1-5 The present invention will be described in further detail below.

[0085] Example 1: A method for preparing a two-dimensional semiconductor phase platinum diselenide single crystal material

[0086] (1) Dissolve 0.05 mol / L chloroplatinic acid and 0.1 mol / L sodium selenosulfate in deionized water to form a liquid-phase precursor solution.

[0087] (2) Take a silicon wafer and clean it with acetone, isopropanol and deionized water in sequence for 10 minutes, then blow it dry with nitrogen.

[0088] (3) Spin-coat the precursor solution onto the silicon wafer surface at a spin speed of 3000 rpm for 30 seconds, and then pre-bake at 100°C for 5 minutes.

[0089] (4) Place the silicon wafer coated with the precursor in a CVD furnace and react under argon protection. The reaction temperature is 500℃, the reaction time is 60 minutes, and the selenium powder evaporation temperature is 250℃.

[0090] (5) After the reaction is complete, the material is naturally cooled to room temperature to obtain a high-quality single-crystal two-dimensional semiconductor PtSe2 material.

[0091] Example 2: A method for preparing a two-dimensional semiconductor phase platinum diselenide single crystal material

[0092] (1) Dissolve 0.03 mol / L chloroplatinic acid and 0.06 mol / L sodium selenosulfate in deionized water to form a liquid-phase precursor solution.

[0093] (2) Take a silicon dioxide substrate and clean it with acetone, isopropanol and deionized water in sequence for 10 minutes, and then blow it dry with nitrogen.

[0094] (3) The precursor solution was drop-coated onto the surface of the silicon dioxide substrate and then pre-baked at 80°C for 10 minutes.

[0095] (4) The substrate coated with the precursor is placed in a CVD furnace and reacted under nitrogen protection. The reaction temperature is 450℃, the reaction time is 90 minutes, and the selenium powder evaporation temperature is 200℃.

[0096] (5) After the reaction is complete, the material is naturally cooled to room temperature to obtain a high-quality single-crystal two-dimensional semiconductor PtSe2 material.

[0097] Working principle: In the method for preparing two-dimensional semiconductor-phase platinum diselenide single crystal materials provided by this invention, the stoichiometric ratio of the platinum source and selenium source can be precisely controlled in the liquid-phase precursor to ensure reaction uniformity. Then, a uniform precursor film can be formed on the substrate surface by spin coating or drop coating, providing a foundation for the growth of high-quality single-crystal PtSe2.

[0098] The CVD reaction temperature is reduced to 400-550℃, minimizing material defects and side reactions caused by high temperatures. This facilitates the formation of high-quality single-crystal PtSe2 while reducing energy consumption. By controlling the selenium powder evaporation temperature and carrier gas flow rate, the selenium vapor concentration is precisely adjusted to ensure a sufficient supply of selenium source during the reaction process and avoid selenium defects.

[0099] Finally, since the method of the present invention is applicable to a variety of substrates (such as silicon wafers, silicon dioxide substrates and flexible substrates), it can effectively improve the versatility of materials and the flexibility of device processing.

[0100] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. A method for preparing a two-dimensional semiconductor phase platinum diselenide single crystal material, characterized in that: Includes the following steps: S1. Preparation of liquid-phase precursors: (1) Dissolve the platinum salt and selenium source in a solvent to form a homogeneous liquid precursor solution, wherein the solvent is a hydrochloric acid solution with a concentration of 0.001-1 M, a sodium hydroxide solution with a concentration of 0.001-1 M, or deionized water, and the platinum salt is chloroplatinic acid, platinum chloride, or platinum sulfate; (2) The molar ratio of platinum salt to selenium source is 2:1 to 1:4 to ensure precise control of stoichiometry; (3) The solution is fully dissolved and uniformly mixed by heating, stirring and ultrasonic treatment to avoid large particle precipitation or phase separation of the precursor solution; S2. Substrate surface pretreatment: (1) Select high-purity silicon wafers, silicon dioxide substrates, or flexible substrates; (2) Clean the surface contaminants by ultrasonic cleaning with acetone, isopropanol and deionized water for 10 minutes in sequence; (3) Dry the substrate with nitrogen gas to ensure the surface is clean and dry; S3. Precursor fixation and nucleation: (1) The liquid precursor solution is uniformly spin-coated onto the substrate surface; (2) The thickness of the precursor film is controlled by spin coating or drop coating. The spin coating speed is 2000-4000 rpm and the time is 30-60 seconds. (3) After coating, pre-bake the substrate at 80-120 °C for 5-10 minutes to remove the solvent; S4.CVD - Gas-Solid Reaction: (1) The substrate coated with the precursor is placed in a CVD furnace and the reaction is carried out under the protection of an inert gas; (2) The reaction temperature is 400-550 ℃, and the reaction time is 30-90 minutes; (3) Selenium vapor is generated by the evaporation of selenium powder at 200-300 °C and is transported to the reaction zone by a carrier gas; (4) By controlling the selenium powder evaporation temperature and carrier gas flow rate, the concentration of selenium vapor is adjusted to ensure uniform reaction; S5. Cooling and Collection: (1) After the reaction is complete, turn off the heating system and allow the furnace to cool naturally to room temperature; (2) Remove the substrate to obtain high-quality single-crystal two-dimensional semiconductor PtSe2 material; (3) The material is characterized by optical microscopy, scanning electron microscopy (SEM) and Raman spectroscopy to ensure its crystal quality and uniformity.

2. The method for preparing a two-dimensional semiconductor phase platinum diselenide single crystal material according to claim 1, characterized in that: The concentration of platinum salt and the concentration of selenium source are 0.02-0.4 mol / L during the preparation of the liquid precursor.

3. The method for preparing a two-dimensional semiconductor phase platinum diselenide single crystal material according to claim 1, characterized in that: The spin coating speed is 3000 rpm and the spin coating time is 30 seconds.

4. The method for preparing a two-dimensional semiconductor phase platinum diselenide single crystal material according to claim 1, characterized in that: The CVD reaction was carried out at a temperature of 500 °C for 60 minutes, and the selenium powder evaporation temperature was 250 °C.

5. The method for preparing a two-dimensional semiconductor phase platinum diselenide single crystal material according to claim 1, characterized in that: The carrier gas flow rate in the CVD reaction is 50-100 sccm.

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