Method for preparing molybdenum disulfide erbium single crystal material, single-layer molybdenum disulfide erbium single crystal material and use

Abstract

The present application relates to a preparation method of a molybdenum disulfide erbium single crystal material, a single-layer molybdenum disulfide erbium single crystal material and an application. In the single-layer molybdenum disulfide erbium single crystal material, a single crystal contains sulfur elements, molybdenum elements and erbium elements; in the crystal of the molybdenum disulfide erbium single crystal alloy, part of the sulfur elements form a covalent bond with the erbium elements, part of the sulfur elements form a covalent bond with the molybdenum elements, and part of the sulfur elements form a covalent bond with the erbium elements and the molybdenum elements at the same time. The single-layer molybdenum disulfide erbium single crystal material provided in the present application realizes the modification of the molybdenum disulfide crystal, replaces the erbium elements in the molybdenum disulfide crystal to the position of molybdenum, obtains the molybdenum disulfide erbium single crystal material, improves the intrinsic electronic properties of the molybdenum disulfide material, and obtains a wide spectral response.

Description

Technical Field

[0001] This invention belongs to the field of two-dimensional material preparation, specifically relating to a method for preparing molybdenum disulfide erbium single crystal material, a single-layer molybdenum disulfide erbium single crystal material, and its applications. Background Technology

[0002] MoS2 is a 2D transition metal chalcogenide compound whose band gap changes from 1.2 eV to 1.9 eV when its thickness is reduced from bulk to monolayer. Furthermore, MoS2's ultrathin layer thickness, strong photo-matter interaction, high carrier mobility, and large on / off ratio make it a promising candidate for high-performance electronic devices and photodetectors. However, for large-scale integrated circuits and room-temperature infrared photodetectors, the intrinsic electron mobility and absorption wavelength range of monolayer MoS2 still cannot meet the requirements of end devices.

[0003] Existing technologies improve the electronic performance of monolayer MoS2-based devices by post-processing lattice defects and optimizing the contact between materials and electrodes. However, these methods do not change the lattice structure and have limited effect on improving the intrinsic electronic properties of monolayer MoS2.

[0004] Therefore, improving the intrinsic electronic properties of MoS2 is a research direction in this field. However, rare earth source materials have high melting points, such as rare earth oxides, most of which have melting points exceeding 2000℃, while transition metal sources can volatilize and diffuse at relatively low temperatures, resulting in different volatilization rates between the two precursors. This makes the synthesis of thermodynamically stable rare earth-doped TMDs materials complicated.

[0005] CN107313023 discloses a method for preparing erbium-doped molybdenum disulfide thin films, aiming to utilize the abundant energy levels occupied by the 4f electron orbitals of erbium ions to achieve electron absorption and emission in the ultraviolet to near-infrared region. Furthermore, the Raman characteristic peak of the erbium-doped molybdenum disulfide thin film prepared by this method is 384 cm⁻¹. -1 and 404cm -1 The peak position difference is 20cm -1 The Raman characteristic peaks are basically the same as those of molybdenum disulfide.

[0006] Because the volatilization rates of erbium and molybdenum sources differ significantly—erbium oxide has a melting point above 2000℃, while molybdenum oxide has a melting point of only around 800℃—and the potential barriers and reaction rates for bonding between molybdenum, erbium, and sulfur atoms also differ greatly, directly using erbium and molybdenum sources as precursors and heating them at 800–1000℃ for chemical vapor deposition cannot truly incorporate erbium into the molybdenum disulfide crystal, resulting in very limited improvement to the intrinsic electronic properties of molybdenum disulfide.

[0007] There is an urgent need in this field to develop a method to improve MoS2 from the perspective of crystal structure, in order to enhance the intrinsic electronic properties of monolayer MoS2. Summary of the Invention

[0008] To address the shortcomings of existing technologies, one objective of this invention is to provide a single-layer molybdenum disulfide erbium single-crystal material, wherein the single crystal contains sulfur, molybdenum, and erbium; in the crystal of the molybdenum disulfide erbium single-crystal alloy, some sulfur elements form covalent bonds with erbium elements, some sulfur elements form covalent bonds with molybdenum elements, and some sulfur elements simultaneously form covalent bonds with both erbium and molybdenum elements.

[0009] In the monolayer molybdenum disulfide erbium single crystal material provided in this application, erbium enters the crystal lattice and forms a single crystal together with sulfur and molybdenum. Its position is primarily at the molybdenum sites within the molybdenum disulfide crystal; that is, in the molybdenum disulfide lattice, positions that should be occupied by molybdenum are replaced by erbium. Compared to existing technologies for erbium doping in molybdenum disulfide materials, the monolayer molybdenum disulfide erbium single crystal material provided in this application truly incorporates erbium into the molybdenum disulfide lattice, thereby improving the intrinsic electronic properties of MoS2.

[0010] Preferably, in the single crystal material, the doping amount of erbium element is 3-12% by atomic number, such as 4%, 6%, 7%, 9%, 10%, 11%, etc., and more preferably 8-12%.

[0011] Preferably, the crystal of the monolayer molybdenum disulfide erbium single crystal material has rounded edges.

[0012] The monolayer molybdenum disulfide erbium single crystal material described in this application exhibits increasingly rounded edges as the amount of erbium entering the crystal lattice increases, potentially forming shapes such as circles or rounded triangles. Furthermore, the crystal tends to become more circular with increasing erbium doping concentration. However, when the erbium content in the crystal lattice is low (approximately less than 8%), it more often presents regular triangles or hexagons.

[0013] The monolayer molybdenum disulfide erbium single crystal material provided in this application can respond to electrical signals over a relatively wide wavelength range. It has been confirmed that the monolayer molybdenum disulfide erbium single crystal material provided in this application has photocurrent signals in the range of 532nm to 2200nm.

[0014] Furthermore, the monolayer molybdenum disulfide erbium single crystal material provided in this application also has a high operating window, especially under high-temperature conditions, such as 150–200℃ (e.g., 160℃, 170℃, 180℃, 190℃), still exhibiting a significant photocurrent signal. This may be because the erbium and sulfur elements form covalent bonds, which suppress the increase in dark current of the device, thereby greatly improving the high-temperature resistance of the device.

[0015] The second objective of this application is to provide a method for preparing molybdenum disulfide erbium single crystal material, including:

[0016] (1) Place an open reaction boat in the first region of the tubular furnace, and place an erbium source and a molybdenum source inside the reaction boat. Then cover it with a porous material layer, place the substrate upside down on the open reaction boat, and leave a gap for the carrier gas to flow through.

[0017] (2) Place sulfur powder in the second region upstream of the tubular furnace;

[0018] (3) After introducing inert carrier gas and exhausting the air in the quartz tube, the tube furnace is heated until the second region reaches above the sulfur powder melting temperature and the first region reaches the chemical vapor deposition temperature of 800-1050℃, and erbium, molybdenum and sulfur elements are deposited to obtain a single-layer molybdenum disulfide erbium single crystal material.

[0019] In the preparation of two-dimensional molybdenum disulfide (MoS2) materials, doping with erbium in the crystal lattice enhances the intrinsic electronic properties of MoS2. However, due to the significant difference in bonding potential between erbium and sulfur atoms and between molybdenum and sulfur atoms, their reaction rates differ considerably, preventing direct doping of erbium into the MoS2 material. To enable both erbium and molybdenum sources to volatilize and undergo chemical vapor deposition on the substrate, the reaction temperature needs to be increased to volatilize both sources simultaneously. However, excessively high temperatures lead to overly vigorous volatilization of the molybdenum source, hindering effective doping of erbium into the crystal (or preventing the formation of an erbium-sulfur-molybdenum alloy). This application addresses this issue by covering the substrate with a porous material layer, allowing for more controllable deposition of both elements on the substrate, thus generating a single-crystal MoS2 erbium disulfide material.

[0020] Furthermore, placing the erbium and molybdenum sources in the reaction boat and placing the substrate upside down on the opening of the reaction boat while leaving gaps allows the sulfur, molybdenum, and erbium sources to react more appropriately on the substrate to generate molybdenum-erbium disulfide alloys, without causing crystal defects due to excessive amounts of any one source.

[0021] Preferably, the gas flow gap includes an upstream gap and a downstream gap arranged along the gas flow direction. This arrangement allows for more stable gas flow and prevents gas flow turbulence from affecting alloy growth.

[0022] Preferably, the erbium source includes any one of erbium oxide, erbium chloride hexahydrate, or a mixture of erbium oxide and sodium chloride.

[0023] Preferably, the molybdenum source includes molybdenum trioxide.

[0024] Preferably, the porous material layer is a 4A molecular sieve.

[0025] Preferably, the substrate comprises a silicon substrate or a sapphire substrate.

[0026] This application does not limit the distance between the substrate and the bottom of the reaction boat, but a suitable distance is beneficial to obtaining a suitable reaction rate. Therefore, the distance between the substrate and the bottom of the reaction boat in this application is preferably 0.4cm to 0.5cm, such as 0.43cm, 0.45cm, 0.48cm, etc.

[0027] Preferably, the erbium source and the molybdenum source are placed separately in the reaction boat. Separate placement avoids the erbium and molybdenum sources reacting directly at high temperatures to form an alloy, which would affect its deposition on the substrate and improve the purity of the molybdenum disulfide erbium single crystal material.

[0028] Preferably, the inert carrier gas includes any one or a combination of at least two of argon, helium, or nitrogen.

[0029] Preferably, the flow rate of the inert carrier gas is 70-90 sccm, such as 75 sccm, 80 sccm, 85 sccm, etc.

[0030] Preferably, the chemical vapor deposition temperature is 900–1000°C, such as 920°C, 950°C, 970°C, 990°C, etc.

[0031] Preferably, the deposition time of the erbium, molybdenum and sulfur elements is 8 to 12 minutes, such as 9 minutes, 10 minutes, 11 minutes, etc.

[0032] Preferably, the heating rate is 25-35℃ / min, such as 26℃ / min, 29℃ / min, 32℃ / min, 34℃ / min, etc.

[0033] Preferably, the melting temperature of the sulfur powder is around 200°C.

[0034] Appropriate temperature, heating rate, deposition time, and carrier gas flow rate can be combined to improve the efficiency of chemical vapor deposition, enhance the quality of molybdenum disulfide erbium alloys, and reduce impurities in the alloy.

[0035] This application also provides a method for preparing a single-layer molybdenum disulfide erbium single crystal material, the method comprising:

[0036] (1) Place an open reaction boat in the first area of ​​the tubular furnace, and place an erbium source and a molybdenum source inside the reaction boat. Then cover it with a 2-2.5 mm thick 4A molecular sieve, place the substrate upside down on the open reaction boat, and leave a gap for the carrier gas to flow through.

[0037] (2) Place sulfur powder in the second region upstream of the tubular furnace;

[0038] (3) Inert carrier gas is introduced at a flow rate of 70-90 sccm. After the air in the quartz tube is exhausted, the tube furnace is heated until the second region reaches above the sulfur powder melting temperature and the first region reaches the chemical vapor deposition temperature of 900-1000℃. Erbium, molybdenum and sulfur elements are deposited to obtain a single-layer molybdenum disulfide erbium single crystal material.

[0039] The third objective of this application is to provide an application of the molybdenum disulfide erbium single crystal material as described in the first objective, wherein the molybdenum disulfide erbium single crystal includes any one or a combination of at least two of the materials used in the fields of semiconductors, infrared photoelectric detection, and sensing.

[0040] It should be noted that the monolayer molybdenum disulfide erbium single crystal material provided in this application can be used alone or in multiple layers. This multilayer structure can be directly achieved through chemical vapor deposition. The molybdenum disulfide erbium single crystal material provided in this application can be single-layered and / or multi-layered.

[0041] Compared with the prior art, this application has the following beneficial effects:

[0042] (1) The monolayer molybdenum disulfide erbium single crystal material provided in this application realizes the modification of molybdenum disulfide crystal by partially replacing the erbium element with the molybdenum position in the molybdenum disulfide crystal, thereby obtaining molybdenum disulfide erbium single crystal material, improving the intrinsic electronic properties of molybdenum disulfide material, obtaining a wide spectral response, and having a wide temperature window.

[0043] (2) The preparation method of molybdenum disulfide erbium single crystal material provided in this application solves the technical problem that the erbium source and molybdenum source have large differences in volatilization temperature and large differences in the bonding barrier with sulfur element, which makes it impossible to obtain molybdenum disulfide erbium single crystal alloy. By adjusting the chemical vapor deposition temperature and setting a porous material layer, molybdenum disulfide erbium single crystal material, especially single-layer molybdenum disulfide erbium single crystal material, is obtained. Attached Figure Description

[0044] Figure 1 An optical micrograph of pure molybdenum disulfide material as a control example;

[0045] Figure 2 X-ray photoelectron spectroscopy of pure molybdenum disulfide material as a control example;

[0046] Figure 3 The Raman spectrum of pure molybdenum disulfide material is shown in the control example.

[0047] Figure 4 The photoluminescence spectrum of pure molybdenum disulfide material is shown in the control example.

[0048] Figure 5 An optical microscope image of the monolayer molybdenum disulfide erbium single crystal material obtained in Example 1;

[0049] Figure 6 The X-ray photoelectron spectrum of the monolayer molybdenum disulfide erbium single crystal material in Example 1 is shown below.

[0050] Figure 7 The image shows the Raman spectrum of the monolayer molybdenum disulfide erbium single crystal material obtained in Example 1.

[0051] Figure 8 The photoluminescence spectrum of the monolayer molybdenum disulfide erbium single crystal material obtained in Example 1 is shown below.

[0052] Figure 9 This is a high-angle annular dark-field scanning transmission electron microscope image of the monolayer molybdenum disulfide erbium single crystal material obtained in Example 1;

[0053] Figure 10 The photoelectric response diagram of the two-dimensional MoS2 material in Comparative Example 1 is shown.

[0054] Figure 11 The photoelectric response diagram of the monolayer molybdenum disulfide erbium single crystal material provided in Example 1 is shown;

[0055] Figure 12 An optical microscope characterization image of the monolayer molybdenum disulfide erbium single crystal material obtained in Example 2;

[0056] Figure 13 The X-ray photoelectron spectrum of the monolayer molybdenum disulfide erbium single crystal material in Example 2 is shown below.

[0057] Figure 14 The image shows the Raman spectrum of the monolayer molybdenum disulfide erbium single crystal material obtained in Example 2.

[0058] Figure 15 The photoluminescence spectrum of the monolayer molybdenum disulfide erbium single crystal material obtained in Example 2 is shown below.

[0059] Figure 16 An optical microscope image of the monolayer molybdenum disulfide erbium single crystal material obtained in Example 3;

[0060] Figure 17 The X-ray photoelectron spectrum of the monolayer molybdenum disulfide erbium single crystal material in Example 3 is shown below.

[0061] Figure 18 The image shows the Raman spectrum of the monolayer molybdenum disulfide erbium single crystal material obtained in Example 3.

[0062] Figure 19 The photoluminescence spectrum of the monolayer molybdenum disulfide erbium single crystal material obtained in Example 3 is shown below.

[0063] Figure 20 An optical microscope image of the molybdenum disulfide erbium single crystal material obtained in Example 4;

[0064] Figure 21 An optical microscope image of the molybdenum disulfide erbium single crystal material obtained in Example 5;

[0065] Figure 22 An optical microscope image of the molybdenum disulfide erbium single crystal material obtained in Example 7;

[0066] Figure 23 An optical microscope image of the molybdenum disulfide erbium single crystal material obtained in Example 4;

[0067] Figure 24 An optical microscope image of the erbium-doped molybdenum disulfide thin film obtained in Comparative Example 1. Detailed Implementation

[0068] The technical solution of the present invention will be further explained and described below with reference to specific embodiments. However, it should be noted that the specific embodiments are only a specific implementation and explanation of the essence of the technical solution of the present invention, and should not be construed as a limitation on the scope of protection of the present invention.

[0069] The reagents and instruments used in the examples are all commercially available, and the detection methods are conventional methods well known in the art.

[0070] Comparison Example

[0071] To illustrate the performance of the molybdenum disulfide erbium single crystal material provided in this application, a pure monolayer MoS2 single crystal material was prepared as a blank control using a method similar to that in the examples. The specific steps are as follows:

[0072] (1) The cut SiO2 / Si substrate was ultrasonicated for 10 minutes each with deionized water, acetone, ethanol and deionized water to remove the adhesive protective layer on the surface of the SiO2 / Si substrate. Then the substrate surface was dried with a nitrogen gun and set aside.

[0073] (2) Place an open reaction boat in the center of the tubular furnace and place 10 mg of molybdenum trioxide (MoO3) in the reaction boat as a molybdenum source. Then cover it with a 2 mm thick 4A molecular sieve (crushed). Place the substrate obtained in step (1) on the open reaction boat and leave a gap for the carrier gas to flow through. Place 80 mg of sulfur powder (S) upstream of the tubular furnace as a sulfur source.

[0074] (3) Argon gas (Ar) is introduced at room temperature to purge the air from the quartz tube, ensuring that the entire growth process is carried out in an inert atmosphere. Argon gas at 80 sccm is used as a carrier gas to transfer the sulfur source. The tubular furnace is heated to above 200°C at the location of the sulfur source and to 900°C at the location of the reaction boat to deposit molybdenum and sulfur elements for 10 min, thereby obtaining pure molybdenum disulfide material.

[0075] Molybdenum disulfide material was characterized by optical microscopy. Figure 1 (Optical micrograph of pure molybdenum disulfide material as a control example) The sample morphology is a regular triangle. Figure 2 ( Figure 2 In the X-ray photoelectron spectrum of the pure molybdenum disulfide material used as a control example, no 4d peak of Er element was detected. Figure 3 ( Figure 3 As can be seen from the Raman spectrum of the pure molybdenum disulfide material (as a control example), the two vibrational modes of the Raman peak of the pure molybdenum disulfide material (A...) 1g and E 1 2g The peak position difference was 20 cm. -1 (404cm -1 and 384cm -1 ).from Figure 4 ( Figure 4 As can be seen from the photoluminescence spectrum of the pure molybdenum disulfide material (as a control example), the photoluminescence spectrum of the pure molybdenum disulfide material has an emission peak at 681 nm.

[0076] Example 1

[0077] A method for preparing a single-layer molybdenum disulfide erbium single crystal material includes:

[0078] (1) The cut SiO2 / Si substrate was ultrasonicated for 10 minutes each with deionized water, acetone, ethanol and deionized water to remove the adhesive protective layer on the surface of the SiO2 / Si substrate. Then the substrate surface was dried with a nitrogen gun and set aside.

[0079] (2) Place an open reaction boat in the central area of ​​the tubular furnace, and place 10 mg of molybdenum trioxide (MoO3) as a molybdenum source, 1 mg of NaCl as an auxiliary agent, and 10 mg of erbium oxide (Er2O3) as an Er precursor in the reaction boat. The molybdenum source and the erbium source are placed separately, and then a 2 mm thick 4A molecular sieve (crushed) is covered on it. The substrate obtained in step (1) is placed on the open reaction boat, and a gap is left for the carrier gas to flow through. Place 80 mg of sulfur powder (S) as a sulfur source upstream of the tubular furnace.

[0080] (3) Argon gas (Ar) is introduced at room temperature to purge the air from the quartz tube, ensuring that the entire growth process is carried out in an inert atmosphere. Argon gas at 80 sccm is used as a carrier gas to transfer the sulfur source. The tube furnace is heated to above 200°C at the location of the sulfur source and to 900°C at the location of the reaction boat to deposit erbium, molybdenum and sulfur elements for 10 min, thereby obtaining a single-layer molybdenum disulfide erbium single crystal material.

[0081] The monolayer molybdenum disulfide erbium single crystal material obtained in Example 1 was characterized by optical microscopy. Figure 5 The image shown is an optical microscope photograph of the monolayer molybdenum disulfide erbium single crystal material obtained in Example 1. The sample morphology is a round triangle and there are no impurity phases. It can be inferred that a large number of erbium elements have entered the crystal lattice, causing the lattice to be distorted and the crystal to have rounded edges. That is, Example 1 obtained a pure monolayer molybdenum disulfide erbium single crystal material.

[0082] The monolayer molybdenum disulfide erbium disulfide single crystal material obtained in Example 1 was characterized by X-ray photoelectron spectroscopy. Figure 6 (The image shows the X-ray photoelectron spectrum of the monolayer molybdenum disulfide erbium single crystal material from Example 1.) Figure 6 In the study, the 4d peak of Er element was detected at 174 eV, indicating that Erbium was indeed heavily doped in the molybdenum disulfide lattice.

[0083] The monolayer molybdenum disulfide erbium disulfide single crystal material obtained in Example 1 was characterized by Raman spectroscopy. Figure 7 (The image shows the Raman spectrum of the monolayer molybdenum disulfide erbium single crystal material obtained in Example 1.) Figure 7 It can be seen that the Raman peak of the monolayer molybdenum disulfide erbium single crystal material obtained in Example 1 exhibits two vibration modes (A... 1g and E 1 2g The peak position difference was 23 cm. -1 (405cm -1 and 382cm -1 (), larger than 20 cm of pure molybdenum disulfide -1 Peak position difference ( Figure 3 The increase in peak position difference is due to the displacement caused by the formation of Er-S bonds, which indicates that doping has changed the lattice structure of the material.

[0084] The single-layer molybdenum disulfide erbium disulfide crystal material obtained in Example 1 was characterized by photoluminescence spectroscopy. Figure 8 (The photoluminescence spectrum of the monolayer molybdenum disulfide erbium single crystal material obtained in Example 1) Figure 8As can be seen, the photoluminescence spectrum of the monolayer molybdenum disulfide erbium single crystal material obtained in this application has an emission peak at 668 nm. Compared with the PL peak position of pure molybdenum disulfide, the PL peak of the Er-doped molybdenum disulfide alloy sample shows a blue shift of 13 nm. This is because erbium doping alters the band structure of the monolayer molybdenum disulfide, introducing new energy levels into the band gap, thus changing the band structure and consequently altering the PL emission energy.

[0085] The monolayer molybdenum disulfide erbium disulfide single crystal material obtained in Example 1 was characterized by high-angle annular dark-field scanning transmission electron microscopy. Figure 9 (High-angle annular dark-field scanning transmission electron microscope image of the monolayer molybdenum disulfide erbium single crystal material obtained in Example 1). Figure 9 In this process, the atomic ratio of molybdenum and erbium at multiple locations is calculated, and the average value is obtained, which is the erbium doping amount. The erbium doping amount of the monolayer molybdenum disulfide erbium single crystal material obtained in Example 1 is about 10%.

[0086] Chromium / gold electrodes were deposited on the two-dimensional MoS2 material of the comparative example and the monolayer molybdenum disulfide erbium single crystal material provided in Example 1, respectively. Photoelectric testing was performed using a KEITHLEY 2614B, with a monochromatic laser source and test wavelengths of 532 nm, 980 nm, 1550 nm, 1850 nm, and 2200 nm. Figure 10 The photoelectric response diagram of the two-dimensional MoS2 material in Comparative Example 1 is shown. Figure 11 The photoelectric response diagram of the monolayer molybdenum disulfide erbium single crystal material provided in Example 1 is shown. It can be seen that the monolayer molybdenum disulfide erbium single crystal material provided in Example 1 can generate signals in the wavelength range of 532 nm to 2200 nm, especially exhibiting a captureable response current in the near-infrared range, while the two-dimensional MoS2 material can only respond around 532 nm. The monolayer molybdenum disulfide erbium single crystal material provided in Example 1 can exhibit photoelectric response signals at 1550 nm under conditions ranging from room temperature to 200 °C.

[0087] Example 2

[0088] The difference from Example 1 is that step (3) is:

[0089] Argon gas (Ar) is first introduced at room temperature to purge the air from the quartz tube, ensuring that the entire growth process is carried out in an inert atmosphere. Argon gas at 70 sccm is used as a carrier gas to transport the sulfur source. The tube furnace is heated to above 200°C at the location of the sulfur source and to 1000°C at the location of the reaction boat to deposit erbium, molybdenum, and sulfur elements for 8 minutes, thereby obtaining a single-layer molybdenum disulfide erbium single crystal material.

[0090] The monolayer molybdenum disulfide erbium single crystal material obtained in Example 2 was characterized by optical microscopy. Figure 12 The image shows an optical microscope characterization of the monolayer molybdenum disulfide erbium single crystal material obtained in Example 2. The sample morphology is close to circular and there are no impurity phases. It can be inferred that more erbium elements have entered the crystal lattice, causing the crystal lattice to be distorted, making the crystal exhibit a smoother rounded edge. That is, Example 2 obtained a pure monolayer molybdenum disulfide erbium single crystal material.

[0091] The monolayer molybdenum disulfide erbium single crystal material obtained in Example 2 was characterized by X-ray photoelectron spectroscopy. Figure 13 (The image shows the X-ray photoelectron spectrum of the monolayer molybdenum disulfide erbium single crystal material in Example 2.) Figure 13 In the study, the 4d peak of Er element was detected at 174 eV, indicating that Erbium was indeed more extensively doped into the molybdenum disulfide lattice.

[0092] The monolayer molybdenum disulfide erbium disulfide single crystal material obtained in Example 2 was characterized by Raman spectroscopy. Figure 14 (The image shows the Raman spectrum of the monolayer molybdenum disulfide erbium single crystal material obtained in Example 2.) Figure 14 It can be seen that the peak position difference between the two vibration modes of the Raman peak of the monolayer molybdenum disulfide erbium single crystal material obtained in Example 2 is 24 cm. -1 (406cm -1 and 382cm -1 ).

[0093] The single-layer molybdenum disulfide erbium disulfide crystal material obtained in Example 2 was characterized by photoluminescence spectroscopy. Figure 15 (The photoluminescence spectrum of the monolayer molybdenum disulfide erbium single crystal material obtained in Example 2) Figure 15 It can be seen that the photoluminescence spectrum of the monolayer molybdenum disulfide erbium single crystal material obtained in this application has an emission peak at 665 nm, which is a blue shift of 16 nm compared to the emission peak of pure molybdenum disulfide.

[0094] The atomic ratio of molybdenum to erbium at multiple positions in the spectrum of the monolayer molybdenum disulfide erbium single crystal material obtained in Example 2 was calculated using a high-angle annular dark-field scanning transmission electron microscope. The erbium doping content of the monolayer molybdenum disulfide erbium single crystal material obtained in Example 2 was approximately 12%.

[0095] The monolayer molybdenum disulfide erbium single crystal material provided in Example 2 can generate signals in the wavelength range of 532 nm to 2200 nm. Furthermore, it exhibits photoelectric response signals at 1550 nm under conditions ranging from room temperature to 200 °C.

[0096] Example 3

[0097] The difference from Example 1 is that step (3) is:

[0098] Argon gas (Ar) is first introduced at room temperature to purge the air from the quartz tube, ensuring that the entire growth process is carried out in an inert atmosphere. Argon gas at 90 sccm is used as a carrier gas to transport the sulfur source. The tube furnace is heated to above 200°C at the location of the sulfur source and to 850°C at the location of the reaction boat to deposit erbium, molybdenum, and sulfur elements for 12 minutes, thereby obtaining a single-layer molybdenum disulfide erbium single crystal material.

[0099] The monolayer molybdenum disulfide erbium single crystal material obtained in Example 3 was characterized by optical microscopy. Figure 16 The image shown is an optical microscope photograph of the monolayer molybdenum disulfide erbium single crystal material obtained in Example 3. The sample has a regular hexagonal morphology and no impurity phases, which suggests that erbium has entered the crystal lattice. Therefore, Example 3 obtained a pure monolayer molybdenum disulfide erbium single crystal material.

[0100] The monolayer molybdenum disulfide erbium single crystal material obtained in Example 3 was characterized by X-ray photoelectron spectroscopy. Figure 17 (The image shows the X-ray photoelectron spectrum of the monolayer molybdenum disulfide erbium single crystal material in Example 3.) Figure 17 In the test, the 4d peak of Er element was detected at 174 eV, indicating that Erbium was indeed doped in the lattice of molybdenum disulfide.

[0101] The monolayer molybdenum disulfide erbium single crystal material obtained in Example 3 was characterized by Raman spectroscopy. Figure 18 (The image shows the Raman spectrum of the monolayer molybdenum disulfide erbium single crystal material obtained in Example 3.) Figure 18 It can be seen that the peak position difference between the two vibration modes of the Raman peak of the monolayer molybdenum disulfide erbium single crystal material obtained in Example 3 is 21 cm. -1 (404cm -1 and 383cm -1 ).

[0102] The single-layer molybdenum disulfide erbium disulfide crystal material obtained in Example 3 was characterized by photoluminescence spectroscopy. Figure 19 (The photoluminescence spectrum of the monolayer molybdenum disulfide erbium single crystal material obtained in Example 3) Figure 19 It can be seen that the photoluminescence spectrum of the monolayer molybdenum disulfide erbium single crystal material obtained in this application has an emission peak at 675 nm, which is a 6 nm blue shift compared to the emission peak of pure molybdenum disulfide.

[0103] Based on the calculation of the atomic ratio of molybdenum and erbium at multiple positions in the spectrum obtained by high-angle annular dark-field scanning transmission electron microscopy, the erbium doping content of the monolayer molybdenum disulfide erbium single crystal material obtained in Example 3 is approximately 5%.

[0104] The monolayer molybdenum disulfide erbium single crystal material provided in Example 3 can generate signals in the wavelength range of 532nm to 1550nm.

[0105] Example 4

[0106] The difference from Example 1 is that after the tubular furnace in step (3) is heated, the reaction boat reaches 1050°C to deposit erbium, molybdenum and sulfur.

[0107] The erbium molybdenum disulfide single crystal material obtained in Example 4 was characterized by optical microscopy. Figure 20 (The image shown is an optical microscope photograph of the molybdenum disulfide erbium single crystal material obtained in Example 4. The sample has a truncated triangular shape and a non-uniform morphology, suggesting that the material is a multilayer sample.)

[0108] The monolayer molybdenum disulfide erbium single crystal material provided in Example 4 can generate signals in the wavelength range of 532 nm to 2200 nm. Furthermore, it exhibits photoelectric response signals at 1550 nm under conditions ranging from room temperature to 200 °C.

[0109] Example 5

[0110] The difference from Example 1 is that the thickness of the 4A molecular sieve (crushed) in step (2) is replaced with 1.5 mm.

[0111] The erbium molybdenum disulfide single crystal material obtained in Example 5 was characterized by optical microscopy. Figure 21 The image shown is an optical microscope photograph of the erbium disulfide single crystal material obtained in Example 5. The sample morphology is not uniform, suggesting that the material is a multilayer sample. This may be because the 4A molecular sieve is relatively thin, resulting in a sparse molecular sieve and more nucleation sites deposited on the substrate surface. Therefore, the grown sample is relatively dense and small in size.

[0112] Example 6

[0113] The difference from Example 1 is that the thickness of the 4A molecular sieve in step (2) is replaced with 2.5 mm.

[0114] The monolayer molybdenum disulfide erbium single crystal material obtained in Example 6 was characterized by optical microscopy, and the sample morphology was triangular.

[0115] Based on the calculation of the atomic ratio of molybdenum and erbium at multiple positions in the spectrum obtained from a high-angle annular dark-field scanning transmission electron microscope, the erbium doping content of the monolayer molybdenum disulfide erbium single crystal material obtained in Example 6 is approximately 3%.

[0116] The monolayer molybdenum disulfide erbium single crystal material provided in Example 2 can generate signals in the wavelength range of 532nm to 980nm.

[0117] Example 7

[0118] The difference from Example 1 is that (2) a reaction boat with an opening is placed in the central area of ​​the tubular furnace, and 10 mg of molybdenum trioxide (MoO3) is placed in the reaction boat as a molybdenum source and 30 mg of erbium chloride (derived by drying erbium chloride hexahydrate) is placed in the reaction boat as an Er precursor. The molybdenum source and the erbium source are placed separately, and then a layer of 4A molecular sieve with a thickness of 2 mm is covered on it. The substrate obtained in step (1) is placed upside down (Si side facing the bottom of the reaction boat) on the reaction boat with an opening, and a gap is left for the carrier gas to flow through. 80 mg of sulfur powder (S) is placed upstream of the tubular furnace as a sulfur source.

[0119] The monolayer molybdenum disulfide erbium single crystal material obtained in Example 7 was characterized by optical microscopy. Figure 22 (An optical microscope image of the molybdenum disulfide erbium single crystal material obtained in Example 7, as shown) Figure 22 As shown, the sample morphology has rounded edges, suggesting the presence of erbium in the crystal lattice. However, other crystals, presumably molybdenum disulfide, are also attached to the crystal. This is likely due to the presence of water of crystallization still present in erbium chloride.

[0120] The monolayer molybdenum disulfide erbium single crystal material provided in Example 7 can generate signals in the wavelength range of 532nm to 1550nm.

[0121] Example 8

[0122] The difference from Example 1 is that (2) a reaction boat with an opening is placed in the central area of ​​the tubular furnace, and 10 mg of molybdenum trioxide (MoO3) as a molybdenum source, 1 mg of NaCl as an auxiliary agent, and 10 mg of erbium oxide (Er2O3) as an Er precursor are placed in the reaction boat. The molybdenum source and the erbium source are mixed and placed, and then a layer of 4A molecular sieve with a thickness of 2 mm is covered on it. The substrate obtained in step (1) is placed upside down (Si side facing the bottom of the reaction boat) on the reaction boat with an opening, and a gap is left for the carrier gas to flow through. 80 mg of sulfur powder (S) is placed upstream of the tubular furnace as a sulfur source.

[0123] The monolayer molybdenum disulfide erbium single crystal material obtained in Example 8 was characterized by optical microscopy. Figure 23 The image shows an optical microscope photograph of the molybdenum disulfide erbium single crystal material obtained in Example 4. As shown in the figure, the sample morphology has rounded edges, which suggests that erbium has entered the crystal lattice. However, there are also linear objects attached around the crystal, which is speculated to be due to the influence of the mixed placement of molybdenum and erbium sources on the combination of molybdenum, erbium, and sulfur into crystals.

[0124] The monolayer molybdenum disulfide erbium single crystal material provided in Example 8 can generate signals in the wavelength range of 532nm to 1550nm.

[0125] Comparative Example 1

[0126] The difference from Example 1 is that step (2) does not involve laying 4A molecular sieves:

[0127] An open reaction boat is placed in the central region of the tubular furnace, and 10 mg of molybdenum trioxide (MoO3) is placed inside the reaction boat as a molybdenum source, 1 mg of NaCl as an auxiliary agent, and 10 mg of erbium oxide (Er2O3) as an Er precursor. The molybdenum source and the erbium source are placed separately. Then, the substrate obtained in step (1) is placed upside down (Si side facing the bottom of the reaction boat) on the open reaction boat, leaving a gap for the carrier gas to flow through. 80 mg of sulfur powder (S) is placed upstream of the tubular furnace as a sulfur source.

[0128] The erbium-doped molybdenum disulfide thin film obtained in Comparative Example 1 was characterized by optical microscopy. Figure 24 (This is an optical microscope image of the erbium-doped molybdenum disulfide thin film obtained in Comparative Example 1). Under conditions without molecular sieves, the precursor volatilizes more violently at high temperatures after reaching a certain temperature. The samples grown under these conditions have uneven thickness and poor crystal quality.

[0129] The monolayer molybdenum disulfide erbium single crystal material provided in Comparative Example 1 can generate signals in the wavelength range of about 532 nm.

[0130] Comparative Example 2

[0131] A method for preparing a single-layer molybdenum disulfide erbium single crystal material includes:

[0132] (1) The cut SiO2 / Si substrate was ultrasonicated for 10 minutes each with deionized water, acetone, ethanol and deionized water to remove the adhesive protective layer on the surface of the SiO2 / Si substrate. Then the substrate surface was dried with a nitrogen gun and set aside.

[0133] (2) In a tube furnace, 80 mg of sulfur powder (S) as a sulfur source, 10 mg of molybdenum trioxide (MoO3) as a molybdenum source, 1 mg of NaCl and 10 mg of erbium oxide (Er2O3) as erbium sources, and the SiO2 / Si substrate of step (1) are placed sequentially along the airflow direction.

[0134] (3) Argon gas (Ar) is introduced at room temperature to purge the air from the quartz tube, ensuring that the entire growth process is carried out in an inert atmosphere. Argon gas at 80 sccm is used as a carrier gas to transport the sulfur source. The tube furnace is heated to above 200°C at the location of the sulfur source and to 950°C at the locations of the erbium and molybdenum sources. The location of the SiO2 / Si substrate is heated to 800°C and held for 40 min to deposit erbium, molybdenum and sulfur elements to obtain an erbium-doped molybdenum disulfide film.

[0135] The erbium-doped molybdenum disulfide thin film obtained in Comparative Example 2 was characterized by optical microscopy. Without the addition of molecular sieves, the sulfur source, erbium source, molybdenum source, and substrate (deposition surface upward) were placed in sequence, but a single layer of molybdenum disulfide erbium single crystal material could not be obtained. When the temperature was raised to 950℃ (800℃ for the substrate), the precursor volatilized violently at high temperature, and the grown sample was uneven in thickness and had poor crystal quality.

[0136] The monolayer molybdenum disulfide erbium single crystal material provided in Comparative Example 2 can generate signals in the wavelength range of about 532 nm.

[0137] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method of producing a single crystal material of molybdenum disulfide erbium, characterized by, The method comprises: (1) placing a reaction boat with an opening in a first region of a tube furnace, and placing an erbium source and a molybdenum source in the reaction boat, then covering 2-2.5 mm thick 4A molecular sieve on it, placing a substrate upside down on the reaction boat with the opening, and reserving a gap for carrier gas to flow; the erbium source and the molybdenum source are placed separately in the reaction boat; (2) placing sulfur powder in a second region upstream of the tube furnace; (3) introducing inert carrier gas, after exhausting the air in the quartz tube, heating the tube furnace, until the second region reaches above the melting temperature of the sulfur powder, and the first region reaches a chemical vapor deposition temperature of 900-1050°C, to deposit erbium, molybdenum and sulfur elements, and obtain a molybdenum disulfide erbium single crystal material; The erbium element of the molybdenum disulfide erbium single crystal material is doped into the crystal lattice of molybdenum disulfide, the doping amount of the erbium element is 3-12%, and the molybdenum disulfide erbium single crystal material has a photoelectric response signal in the range of 532nm-2200nm, and still has a significant photoelectric response signal under the condition of 150-200°C.

2. The production method according to claim 1, wherein The erbium source includes any one of erbium oxide, erbium chloride hexahydrate, or a mixture of erbium oxide and sodium chloride.

3. The production method according to claim 1, wherein The molybdenum source includes molybdenum trioxide.

4. The production method according to claim 1, wherein The substrate includes a silicon substrate or a sapphire substrate.

5. The production method according to claim 1, wherein The inert carrier gas includes any one or a combination of at least two of argon, helium or nitrogen.

6. The production method according to claim 1, wherein The flow rate of the inert carrier gas is 70-90sccm.

7. The production method according to claim 1, wherein The chemical vapor deposition temperature is 900-1000°C.

8. The production method according to claim 1, wherein The deposition time of the erbium, molybdenum and sulfur elements is 8-12min.

9. The production method according to claim 1, wherein The heating rate of the heating is 25-35°C / min.

10. The production method according to claim 1, wherein The method comprises: (1) placing a reaction boat with an opening in a first region of a tube furnace, and placing an erbium source and a molybdenum source in the reaction boat, then covering 2-2.5 mm thick 4A molecular sieve on it, placing a substrate upside down on the reaction boat with the opening, and reserving a gap for carrier gas to flow; the erbium source and the molybdenum source are placed separately in the reaction boat; (2) placing sulfur powder in a second region upstream of the tube furnace; (3) introducing inert carrier gas at a flow rate of 70-90sccm, after exhausting the air in the quartz tube, heating the tube furnace, until the second region reaches above the melting temperature of the sulfur powder, and the first region reaches a chemical vapor deposition temperature of 900-1000°C, to deposit erbium, molybdenum and sulfur elements, and obtain a single-layer molybdenum disulfide erbium single crystal material; The erbium element of the molybdenum disulfide erbium single crystal material is doped into the crystal lattice of molybdenum disulfide, the doping amount of the erbium element is 3-12%, and the molybdenum disulfide erbium single crystal material has a photoelectric current signal in the range of 532nm-2200nm, and can have a photoelectric signal under the condition of 150-200°C.

11. A molybdenum disulfide erbium single crystal material obtained by the preparation method of any one of claims 1-10.

12. Use of a single crystal of molybdenum disulfide erbium as claimed in claim 11, characterized in that, The molybdenum disulfide erbium single crystal is applied to semiconductors.

13. Use of a single crystal material of molybdenum disulfide erbium as claimed in claim 11, characterized in that, The molybdenum disulfide erbium single crystal is applied to infrared photoelectric detection.

14. Use of a single crystal material of molybdenum disulfide erbium as claimed in claim 11, characterized in that, The molybdenum disulfide erbium single crystal is applied to materials in the field of sensing.

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