A synthesis method of a two-dimensional tellurium selenium heterojunction based on a two-dimensional tellurium template method

Abstract

The application discloses a synthesis method of a two-dimensional tellurium selenium heterojunction based on a two-dimensional tellurium template method, and the synthesis method comprises the following steps: providing a two-dimensional tellurium crystal; dissolving the two-dimensional tellurium crystal in water to obtain a first solution; dissolving selenium powder in hydrazine hydrate to obtain a second solution; mixing the first solution and the second solution according to a molar ratio of 1:1, and reacting at 180 DEG C for 8-14 hours to obtain a two-dimensional tellurium selenium heterojunction. The two-dimensional tellurium selenium heterojunction is obtained by using the hydrothermal method for epitaxial growth according to the similar atomic structure of selenium and tellurium. The method has the characteristics of low temperature and low pressure, simple operation, low cost and industrialization. Moreover, the two-dimensional tellurium selenium heterojunction can greatly improve the photoelectric detection performance of the two-dimensional tellurium.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of two-dimensional nanomaterial preparation, and particularly relates to a synthesis method of a two-dimensional tellurium-selenium heterojunction based on a two-dimensional tellurium template method. BACKGROUND

[0002] Two-dimensional materials can meet the needs of future large-scale photonic integrated circuits in high speed and low power consumption in terms of process processing and optical performance. Two-dimensional materials have super-high carrier mobility, strong light-matter interaction and interlayer van der Waals force combination, and can be combined with integrated optics to realize high-speed, efficient and easy-to-process optoelectronic devices. At present, two-dimensional materials are widely used in integrated platform laser sources, optical modulators and photodetectors. Among them, the application of photodetectors attracts a large number of scientific researches because the band gap of two-dimensional materials is wide and can cover a wide wavelength range, and the very large specific surface makes it have outstanding effect in photoelectric absorption. In the research of two-dimensional atomic crystal materials as channel materials, designing and preparing heterojunction materials with adjustable atomic structure and optoelectronic properties is an important basis for realizing new functions and new applications, and is also a hot spot and difficulty in current two-dimensional heterojunction research. The controllable construction of two-dimensional heterojunction with adjustable interface band arrangement can provide rich material resources for the development of nanometer optoelectronic devices and accelerate the development of two-dimensional semiconductor devices in the fields of diversification, multifunction, wide spectrum response and tunable optoelectronic devices.

[0003] Two-dimensional tellurium is a typical narrow-bandgap p-type semiconductor, and its bulk material has a band gap of 0.35 electron volts, has good light absorption (1 μm-3 μm) for near-infrared and mid-infrared bands, and has super-high carrier mobility (the hole mobility of tellurium can reach 700 square centimeters per volt per second), which is a good candidate for two-dimensional infrared photodetectors. Focusing on the photoconductive type photodetector of tellurium as a single material, although it can realize wide-spectrum infrared light response, but due to the large dark current, it will cause large device power consumption. In the past research, a method of directly transferring an N-type material such as two-dimensional transition metal oxide and a P-type material of tellurium to form a heterojunction has been adopted to improve the performance of the photodetector. However, there is no work to grow an N-type material on the surface of tellurium using tellurium as a seed. The advantage of this is that it can reduce impurities and other adverse factors caused by the transfer process, and the combination at the interface is more compact, which can effectively make the photo-generated carriers migrate in this area.

[0004] Selenium and tellurium are elements of the same group and have similar one-dimensional van der Waals force helical structures. At the same time, it is an N-type material. Therefore, if a certain growth method can form this tellurium-selenium heterojunction, a tight interface can be formed, and the lattice structure can be matched. This heterojunction can shine in the fields of optoelectronics and electronics. SUMMARY

[0005] In view of this, the present application provides a synthesis method of a two-dimensional tellurium selenium heterojunction based on a two-dimensional tellurium template method.

[0006] According to a first aspect of an embodiment of the present application, a synthesis method of a two-dimensional tellurium selenium heterojunction based on a two-dimensional tellurium template method is provided, and the synthesis method comprises:

[0007] providing a two-dimensional telluriumene crystal;

[0008] dissolving the two-dimensional telluriumene crystal in water to obtain a first solution;

[0009] dissolving selenium powder in hydrazine hydrate to obtain a second solution;

[0010] mixing the first solution and the second solution at a molar ratio of 1:1, and reacting at 180℃ for 8-14 hours to obtain a two-dimensional tellurium selenium heterojunction.

[0011] Further, the two-dimensional telluriumene crystal is provided and comprises:

[0012] 0.1g of sodium tellurite and 0.5g of polyvinylpyrrolidone with a molecular weight of 55000 are dissolved in 30mL of deionized water with a conductivity of 18.2MΩ·cm to form a solution A with a concentration of 0.014mol / L, then 1.65mL of hydrazine hydrate and 3.3mL of ammonia water are mixed to form solution B and added to solution A, and then placed in a hydrothermal reaction container, sealed and reacted in a 160℃ oven for 30 hours to obtain the product two-dimensional telluriumene crystal.

[0013] Further, the concentration of the second solution is 0.025-0.1mol / L.

[0014] Further, the concentration of the second solution is 0.05mol / L.

[0015] Further, the selenium powder is dissolved in hydrazine hydrate at 30-50℃.

[0016] Further, the selenium powder is dissolved in hydrazine hydrate at 40℃.

[0017] Further, the first solution and the second solution are reacted at 180℃ for 10 hours.

[0018] Further, the synthesis method further comprises:

[0019] washing the two-dimensional tellurium selenium heterojunction, transferring the washed two-dimensional tellurium selenium heterojunction to a silicon wafer to observe the morphology, and obtaining the results of EDS energy spectrum analysis.

[0020] According to a second aspect of the embodiment of the present application, a two-dimensional tellurium selenium heterojunction is provided, which is prepared by the synthesis method of the two-dimensional tellurium selenium heterojunction based on the two-dimensional tellurium template method.

[0021] According to a third aspect of the embodiment of the present application, a field effect transistor is provided, which comprises a back-gate substrate, a source and a drain arranged on both sides of the upper surface of the substrate, and the two-dimensional tellurium selenium heterojunction described above arranged between the upper surface of the substrate and the source and the drain.

[0022] The beneficial effects of the present application are as follows:

[0023] (1) The present application uses a new material, two-dimensional tellurium sheet, as a template to prepare a two-dimensional tellurium selenium heterojunction with high quality and high crystallinity through wet chemical method. The two-dimensional tellurium selenium heterojunction has the same morphology as the template and can be used to prepare various optoelectronic and electronic devices.

[0024] (2) The present application characterizes the photoelectric properties of the tellurium selenium heterojunction and finds that it has high photoelectric detection responsivity.

[0025] (3) The process of the present application is simple and controllable, has a short preparation period, is safe and pollution-free, and is inexpensive. According to actual production requirements, two-dimensional heterojunctions of different thicknesses can be prepared flexibly, providing a new idea for the application of tellurium in the field of optoelectronics. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0027] Figure 1 is a flowchart of a synthesis method of a two-dimensional tellurium selenium heterojunction based on a two-dimensional tellurium template method provided by the embodiment of the present application;

[0028] Figure 2 is a morphology photograph of tellurium before reaction in Example 1 of the present application;

[0029] Figure 3 is basic thickness information of tellurium before reaction in Example 1 of the present application;

[0030] Figure 4 is scanning microscopic information of the two-dimensional tellurium selenium heterojunction obtained in Example 1 of the present application;

[0031] Figure 5 is an EDS mapping picture of the two-dimensional tellurium selenium heterojunction obtained in Example 1 of the present application;

[0032] Figure 6 is a light detection device picture of the two-dimensional tellurium selenium obtained by the embodiment 1 of the present application;

[0033] Figure 7 is a current-voltage curve picture of the two-dimensional tellurium selenium heterojunction light detection performance obtained by the embodiment 1 of the present application;

[0034] Figure 8 is a scanning electron microscope picture of the two-dimensional tellurium selenium heterojunction obtained by the embodiment 2 of the present application;

[0035] Figure 9 is an EDS Mapping result picture of the two-dimensional tellurium selenium heterojunction obtained by the embodiment 2 of the present application;

[0036] Figure 10 is a scanning electron microscope picture of the two-dimensional tellurium selenium heterojunction obtained by the embodiment 3 of the present application;

[0037] Figure 11 is an EDS Mapping result picture of the two-dimensional tellurium selenium heterojunction obtained by the embodiment 4 of the present application;

[0038] Figure 12 is a scanning electron microscope picture of the two-dimensional tellurium selenium heterojunction obtained by the embodiment 5 of the present application. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0040] It should be noted that the features in the following embodiments and implementation manners can be combined with each other without conflict.

[0041] The embodiment of the present application provides a synthesis method of a two-dimensional tellurium selenium heterojunction based on a two-dimensional tellurium template method. The two-dimensional telluriumene synthesized by a first-step hydrothermal method is used as a crystal seed, and a layer of selenium is grown on the telluriumene by using a hydrothermal method, so as to finally form a tellurium-selenium heterojunction, and the high photoelectric detection characteristics are tested. The method can effectively control the composition and morphology. Compared with other two-dimensional material heterojunction preparation methods such as pulsed laser deposition (PLD) and molecular beam epitaxy (MBE), the method shows the characteristics of simplicity, controllability and mass production.

[0042] As shown in Figure 1 , the method specifically comprises:

[0043] S1, providing a two-dimensional telluriumene crystal;

[0044] In the embodiments of the present application, the two-dimensional tellurene crystals are prepared by the steps in <Wang Yixiu, Qiu Gang, Wang Ruoxing, et al. Field-effect transistors made from solution-grown two-dimensional tellurene [J]. Nature Electronics, 2018, 1(4): 228-236. doi: 10.1038 / s41928-018-0058-4>.

[0045] 0.1 g of sodium tellurite and 0.5 g of polyvinylpyrrolidone with a molecular weight of 55000 are dissolved in 30 mL of deionized water with a conductivity of 18.2 MΩ·cm, stirred under a magnetic stirrer for 30 minutes to form solution A with a concentration of 0.014 mol / L, then 1.65 mL of hydrazine hydrate and 3.3 mL of ammonia water are mixed to form solution B, which is added to solution A and placed in a hydrothermal reactor, sealed and reacted in a 160℃ oven for 30 hours, and then taken out to obtain the product two-dimensional tellurene. The morphology of the two-dimensional tellurium nanocrystals can be observed under a microscope, which has a width of about 15 microns, a length of 80 microns, and a thickness of only a few tens of nanometers.

[0046] Step S2, dissolving the two-dimensional tellurene crystals in water to obtain a first solution.

[0047] Specifically, the two-dimensional tellurene crystals are washed with deionized water for 3-4 times to obtain the first solution.

[0048] Step S3, dissolving selenium powder in hydrazine hydrate to obtain a second solution;

[0049] Further, the concentration of the second solution is 0.025-0.1 mol / L, preferably 0.05 mol / L.

[0050] Further, the selenium powder is dissolved in hydrazine hydrate at 30-50℃, preferably at 40℃.

[0051] Step S4, epitaxial growth in a hydrothermal reactor to obtain a tellurium-selenium heterojunction structure: mixing the first solution and the second solution at a molar ratio of 1:1, reacting at 180℃ for 10-13 hours to obtain a two-dimensional tellurium-selenium heterojunction.

[0052] Embodiment 1

[0053] This embodiment 1 is a preferred embodiment of the synthesis method of the two-dimensional tellurium-selenium heterojunction based on the two-dimensional tellurium template method provided by the present application, which specifically includes the following steps:

[0054] Step S1, providing a two-dimensional tellurene crystal. Figure 2 A morphology photograph of tellurene before reaction is shown. Figure 3 Basic thickness information of tellurene before reaction is shown.

[0055] Step S2, after the two-dimensional tellurene crystal is washed with deionized water for 3-4 times, a first solution with a concentration of 0.05 mol / L is obtained.

[0056] Step S3, the selenium powder is dissolved in hydrazine hydrate by heating to 40℃, and a second solution with a concentration of 0.05 mol / L is obtained.

[0057] Step S4, epitaxial growth is carried out in a hydrothermal reaction kettle to obtain a tellurium-selenium heterojunction structure: equal volumes of the first solution and the second solution are mixed, and a two-dimensional tellurium-selenium heterojunction is obtained by reacting at 180 degrees for 10 hours. The morphology thereof is shown in Figure 4

[0058] Step S5: the two-dimensional tellurium-selenium heterojunction is washed with deionized water and a centrifuge for three times, and then transferred to a silicon wafer to observe the morphology thereof, and the results of EDS mapping thereof are shown in Figure 5 Figure 5 It can be seen that the template morphology of tellurene is unchanged, and selenium element is epitaxially grown on the template normally, and the surface is smooth.

[0059] Step S6: the obtained heterojunction is prepared into a photoelectric detector to test its photoelectric detection performance: the clean two-dimensional tellurium-selenium heterojunction is transferred to a silicon wafer, and a standard two-end photoelectric detector device is prepared by using a standard micro-nano processing process (glue spinning, exposure, development, metal evaporation) as shown in Figure 6 The photoelectric performance thereof is shown in Figure 7

[0060] As can be seen from the preferred example, the EDS mapping of the two-dimensional tellurium-selenium heterojunction product of the present application can prove that selenium can be epitaxially grown directly on the surface of tellurium. The product has semiconductor characteristics through the prepared photoelectric device, and the photoelectric responsivity thereof can be 377 A / W at a wavelength of 532 nm. It is shown that the two-dimensional tellurium-selenium heterojunction has potential application in the field of photoelectric devices.

[0061] Example 2

[0062] Step S1, providing a two-dimensional tellurene crystal;

[0063] Step S2, the product two-dimensional tellurene crystal of step S1 is washed with deionized water for three times to obtain a first solution with a concentration of 0.05 mol / L.

[0064] ​​​Step S3, selenium powder is dissolved in hydrazine hydrate at 40 degrees to obtain a second solution of 0.025 mol / L.

[0065] Step S4, the first solution and the second solution are mixed in a volume ratio of 1:1, and reacted at 180 degrees for 10 hours to obtain a heterojunction product. The morphology thereof is shown in Figure 8 .

[0066] Step S5, the product is washed with deionized water and a centrifuge three times, and then transferred to a silicon wafer to observe the morphology thereof, and the results of EDS mapping thereof are shown in Figure 9 .

[0067] This embodiment 2 is to reduce the concentration of the selenium solution by half, and it can be seen that the template morphology of tellurene remains unchanged, but from the EDS mapping, it can be seen that the element of selenium is very small, so the concentration of the raw material of the reaction should not be too low.

[0068] Embodiment 3

[0069] Step S1, provide a two-dimensional tellurene crystal;

[0070] Step S2, the product two-dimensional tellurene crystal of S1 is washed with deionized water three times to obtain a first solution of 0.05 mol / L.

[0071] Step S3, selenium powder is dissolved in hydrazine hydrate at 40 degrees to obtain a second solution of 0.1 mol / L.

[0072] Step S4, the first solution and the second solution are mixed in a volume ratio of 1:1, and reacted at 180 degrees for 10 hours to obtain a heterojunction product. The morphology thereof is shown in Figure 10 .

[0073] This embodiment 3 is to increase the concentration of the selenium solution by half, and the template morphology of tellurene has changed, there are many defects and breaks due to stress on the surface, so the concentration of the raw material of the reaction should not be too high.

[0074] Embodiment 4

[0075] Step S1, provide a two-dimensional tellurene crystal;

[0076] Step S2, the product two-dimensional tellurene crystal of S1 is washed with deionized water three times to obtain a first solution of 0.05 mol / L.

[0077] Step S3, selenium powder is dissolved in hydrazine hydrate at 40 degrees to obtain a second solution of 0.05 mol / L.

[0078] Step S4, the first solution and the second solution are mixed in a volume ratio of 1:1, and the heterojunction product is obtained by reacting at 180 degrees for 5 hours.

[0079] Step S5, the heterojunction product obtained in step S4 is washed with deionized water and a centrifuge three times, and then transferred to a silicon wafer to observe its morphology, and the results of its EDS mapping are shown in Figure 11

[0080] This embodiment 4 is to change the reaction time of growing selenium to 5 hours, and finally from the EDS mapping figure, it can be found that the selenium element content on the two-dimensional telluriumene is very small, which shows that the reaction is incomplete, and the heterojunction has not been successfully synthesized. This embodiment shows that the reaction time of step S3 is also very important and should not be too short.

[0081] Embodiment 5

[0082] Step S1, provide two-dimensional telluriumene crystals.

[0083] Step S2, the product two-dimensional telluriumene crystals of step S1 are washed with deionized water three times to obtain a first solution of 0.05 mol / L.

[0084] Step S3, dissolve selenium powder in hydrazine hydrate at 40 degrees to obtain a second solution of 0.05 mol / L.

[0085] Step S4, the first solution and the second solution are mixed in a volume ratio of 1:1, and the heterojunction product is obtained by reacting at 180 degrees for 15 hours. Its morphology is shown in Figure 12

[0086] This embodiment 5 is to extend the reaction time, and its morphology also changes, the surface becomes rough, which is not suitable for subsequent device work. This embodiment shows that the reaction time should not be too long.

[0087] Embodiment 6

[0088] Step S1, provide two-dimensional telluriumene crystals.

[0089] Step S2, the product two-dimensional telluriumene crystals of step S1 are washed with deionized water three times to obtain a first solution of 0.05 mol / L.

[0090] Step S3, dissolve selenium powder in hydrazine hydrate at 40 degrees to obtain a second solution of 0.05 mol / L.

[0091] Step S4, epitaxial growth in a hydrothermal reactor to obtain a tellurium-selenium heterojunction structure: mix equal volumes of the first solution and the second solution, and react at 180 degrees for 8 hours to obtain a two-dimensional tellurium-selenium heterojunction. ​​

[0092] The heterojunction is prepared into a photodetector to test its photodetection performance, and the results show that the template morphology of the tellurene is unchanged, the selenium element is normally epitaxially grown on the template, the surface is smooth, and the two-dimensional tellurium selenium heterojunction product has semiconductor characteristics.

[0093] Example 7

[0094] Step S1, providing a two-dimensional tellurene crystal.

[0095] Step S2, the product two-dimensional tellurene crystal of step S1 is washed with deionized water for three times to obtain a first solution of 0.05 mol / L.

[0096] Step S3, the selenium powder is dissolved in hydrazine hydrate heated to 40 DEG C to obtain a second solution of 0.05 mol / L.

[0097] Step S4, epitaxial growth in a hydrothermal reaction kettle to obtain a tellurium selenium heterojunction structure: mixing equal volumes of the first solution and the second solution, reacting at 180 degrees for 9 hours to obtain a two-dimensional tellurium selenium heterojunction.

[0098] The heterojunction is prepared into a photodetector to test its photodetection performance, and the results show that the template morphology of the tellurene is unchanged, the selenium element is normally epitaxially grown on the template, the surface is smooth, and the two-dimensional tellurium selenium heterojunction product has semiconductor characteristics.

[0099] Example 8

[0100] Step S1, providing a two-dimensional tellurene crystal.

[0101] Step S2, the product two-dimensional tellurene crystal of step S1 is washed with deionized water for three times to obtain a first solution of 0.05 mol / L.

[0102] Step S3, the selenium powder is dissolved in hydrazine hydrate heated to 40 DEG C to obtain a second solution of 0.05 mol / L.

[0103] Step S4, epitaxial growth in a hydrothermal reaction kettle to obtain a tellurium selenium heterojunction structure: mixing equal volumes of the first solution and the second solution, reacting at 180 degrees for 9 hours to obtain a two-dimensional tellurium selenium heterojunction.

[0104] The heterojunction is prepared into a photodetector to test its photodetection performance, and the results show that the template morphology of the tellurene is unchanged, the selenium element is normally epitaxially grown on the template, the surface is smooth, and the two-dimensional tellurium selenium heterojunction product has semiconductor characteristics.

[0105] Example 9

[0106] Step S1, providing a two-dimensional tellurene crystal.

[0107] Step S2, the product two-dimensional tellurene crystal of step S1 is washed with deionized water for three times to obtain a first solution of 0.05 mol / L.

[0108] Step S3, the selenium powder is dissolved in hydrazine hydrate heated to 40℃ to obtain a second solution of 0.05 mol / L.

[0109] Step S4, epitaxial growth in a hydrothermal reactor to obtain a tellurium-selenium heterojunction structure: mix equal volumes of the first solution and the second solution, react at 180 degrees for 12 hours to obtain a two-dimensional tellurium-selenium heterojunction.

[0110] By observing the results of its EDS mapping, and preparing the heterojunction into a photodetector to test its photodetection performance, the results show that the template morphology of the tellurene is unchanged, the selenium element is normally epitaxially grown on the template, the surface is smooth, and the two-dimensional tellurium-selenium heterojunction product has semiconductor characteristics.

[0111] Example 10

[0112] Step S1, providing a two-dimensional tellurene crystal.

[0113] Step S2, the product two-dimensional tellurene crystal of step S1 is washed with deionized water for three times to obtain a first solution of 0.05 mol / L.

[0114] Step S3, the selenium powder is dissolved in hydrazine hydrate heated to 40℃ to obtain a second solution of 0.05 mol / L.

[0115] Step S4, epitaxial growth in a hydrothermal reactor to obtain a tellurium-selenium heterojunction structure: mix equal volumes of the first solution and the second solution, react at 180 degrees for 13 hours to obtain a two-dimensional tellurium-selenium heterojunction.

[0116] By observing the results of its EDS mapping, and preparing the heterojunction into a photodetector to test its photodetection performance, the results show that the template morphology of the tellurene is unchanged, the selenium element is normally epitaxially grown on the template, the surface is smooth, and the two-dimensional tellurium-selenium heterojunction product has semiconductor characteristics.

[0117] Example 11

[0118] Step S1, providing a two-dimensional tellurene crystal.

[0119] Step S2, the product two-dimensional tellurene crystal of step S1 is washed with deionized water for three times to obtain a first solution of 0.05 mol / L.

[0120] Step S3, dissolve the selenium powder in hydrazine hydrate at 40°C to obtain a second solution with a concentration of 0.05 mol / L.

[0121] Step S4, epitaxial growth in a hydrothermal reaction kettle to obtain a tellurium-selenium heterojunction structure: mix equal volumes of the first solution and the second solution, and react at 180 degrees for 14 hours to obtain a two-dimensional tellurium-selenium heterojunction.

[0122] By observing the results of the EDS mapping and preparing the heterojunction into a photodetector to test its photodetection performance, it is found that the template morphology of the tellurene remains unchanged, the selenium element is epitaxially grown on the template normally, the surface is smooth, and the two-dimensional tellurium-selenium heterojunction product has semiconductor characteristics.

[0123] Example 12

[0124] Step S1, provide a two-dimensional tellurene crystal.

[0125] Step S2, after washing the product two-dimensional tellurene crystal of step S1 with deionized water three times, a first solution with a concentration of 0.06 mol / L is obtained.

[0126] Step S3, dissolve the selenium powder in hydrazine hydrate at 40°C to obtain a second solution with a concentration of 0.06 mol / L.

[0127] Step S4, epitaxial growth in a hydrothermal reaction kettle to obtain a tellurium-selenium heterojunction structure: mix equal volumes of the first solution and the second solution, and react at 180 degrees for 12 hours to obtain a two-dimensional tellurium-selenium heterojunction.

[0128] By observing the results of the EDS mapping and preparing the heterojunction into a photodetector to test its photodetection performance, it is found that the template morphology of the tellurene remains unchanged, the selenium element is epitaxially grown on the template normally, the surface is smooth, and the two-dimensional tellurium-selenium heterojunction product has semiconductor characteristics.

[0129] Example 13

[0130] Step S1, provide a two-dimensional tellurene crystal.

[0131] Step S2, after washing the product two-dimensional tellurene crystal of step S1 with deionized water three times, a first solution with a concentration of 0.04 mol / L is obtained.

[0132] Step S3, dissolve the selenium powder in hydrazine hydrate at 40°C to obtain a second solution with a concentration of 0.04 mol / L.

[0133] Step S4, epitaxial growth in a hydrothermal reactor to obtain tellurium-selenium heterojunction structure: mix equal volumes of the first solution and the second solution, react at 180 degrees for 12 hours to obtain a two-dimensional tellurium-selenium heterojunction.

[0134] By observing the results of its EDS mapping, and preparing the heterojunction into a photodetector to test its photodetection performance, the results show that the template morphology of tellurene is unchanged, selenium element is epitaxially grown on the template normally, the surface is smooth, and the two-dimensional tellurium-selenium heterojunction product has semiconductor characteristics.

[0135] Example 14

[0136] Step S1, provide two-dimensional tellurene crystals.

[0137] Step S2, after the product two-dimensional tellurene crystals of step S1 are washed with deionized water for three times, a first solution with a concentration of 0.035 ol / L is obtained.

[0138] Step S3, dissolve selenium powder in hydrazine hydrate at 35 degrees to obtain a second solution with a concentration of 0.035 ol / L.

[0139] Step S4, epitaxial growth in a hydrothermal reactor to obtain tellurium-selenium heterojunction structure: mix equal volumes of the first solution and the second solution, react at 180 degrees for 12 hours to obtain a two-dimensional tellurium-selenium heterojunction.

[0140] By observing the results of its EDS mapping, and preparing the heterojunction into a photodetector to test its photodetection performance, the results show that the template morphology of tellurene is unchanged, selenium element is epitaxially grown on the template normally, the surface is smooth, and the two-dimensional tellurium-selenium heterojunction product has semiconductor characteristics.

[0141] Example 15

[0142] Step S1, provide two-dimensional tellurene crystals.

[0143] Step S2, after the product two-dimensional tellurene crystals of step S1 are washed with deionized water for three times, a first solution with a concentration of 0.08 mol / L is obtained.

[0144] Step S3, dissolve selenium powder in hydrazine hydrate at 40 degrees to obtain a second solution with a concentration of 0.08 mol / L.

[0145] Step S4, epitaxial growth in a hydrothermal reactor to obtain tellurium-selenium heterojunction structure: mix equal volumes of the first solution and the second solution, react at 180 degrees for 12 hours to obtain a two-dimensional tellurium-selenium heterojunction.

[0146] The template morphology of the tellurene is unchanged, the selenium element is normally epitaxially grown on the template, the surface is smooth, and the two-dimensional tellurium selenium heterojunction product has semiconductor characteristics.

[0147] Example 16

[0148] Step S1, providing a two-dimensional tellurene crystal.

[0149] Step S2, the product two-dimensional tellurene crystal of step S1 is washed with deionized water for three times to obtain a first solution with a concentration of 0.085 mol / L.

[0150] Step S3, the selenium powder is dissolved in hydrazine hydrate at 35 DEG C to obtain a second solution with a concentration of 0.085 mol / L.

[0151] Step S4, epitaxial growth in a hydrothermal reaction kettle to obtain a tellurium selenium heterojunction structure: mixing equal volumes of the first solution and the second solution, reacting at 180 degrees for 12 hours to obtain a two-dimensional tellurium selenium heterojunction.

[0152] The template morphology of the tellurene is unchanged, the selenium element is normally epitaxially grown on the template, the surface is smooth, and the two-dimensional tellurium selenium heterojunction product has semiconductor characteristics.

[0153] Example 17

[0154] Step S1, providing a two-dimensional tellurene crystal.

[0155] Step S2, the product two-dimensional tellurene crystal of step S1 is washed with deionized water for three times to obtain a first solution with a concentration of 0.075 mol / L.

[0156] Step S3, the selenium powder is dissolved in hydrazine hydrate at 35 DEG C to obtain a second solution with a concentration of 0.075 mol / L.

[0157] Step S4, epitaxial growth in a hydrothermal reaction kettle to obtain a tellurium selenium heterojunction structure: mixing equal volumes of the first solution and the second solution, reacting at 180 degrees for 10 hours to obtain a two-dimensional tellurium selenium heterojunction.

[0158] The template morphology of the tellurene is unchanged, the selenium element is normally epitaxially grown on the template, the surface is smooth, and the two-dimensional tellurium selenium heterojunction product has semiconductor characteristics.

[0159] Example 18

[0160] Step S1, providing a two-dimensional tellurene crystal.

[0161] Step S2, the product two-dimensional tellurene crystal of step S1 is washed three times with deionized water to obtain a first solution with a concentration of 0.095 mol / L.

[0162] Step S3, the selenium powder is dissolved in hydrazine hydrate at 30°C to obtain a second solution with a concentration of 0.095 mol / L.

[0163] Step S4, epitaxial growth in a hydrothermal reactor to obtain a tellurium-selenium heterojunction structure: mix equal volumes of the first solution and the second solution, and react at 180 degrees for 11 hours to obtain a two-dimensional tellurium-selenium heterojunction.

[0164] The results of observing the EDS mapping thereof, and the preparation of the heterojunction into a photodetector to test its photodetection performance, show that the template morphology of the tellurene is unchanged, the selenium element is normally epitaxially grown on the template, the surface is smooth, and the two-dimensional tellurium-selenium heterojunction product has semiconductor properties.

[0165] Other embodiments of the application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. It is intended that the application be construed as including any variations, uses or adaptations of the application following, in general, the principles of the application and including such insubstantial variations and changes as come within the scope of the application. The specification and examples are to be regarded as exemplary only.

[0166] It should be understood that the application is not limited to the precise construction that has been described above and illustrated in the accompanying drawings and that various modifications and changes can be made by those skilled in the art without departing from the scope of the application.

Claims

1. A method for synthesizing two-dimensional tellurium selenium heterojunctions based on two-dimensional tellurium template method, characterized in that, The synthesis method comprises: providing a two-dimensional tellurene crystal; dissolving the two-dimensional tellurene crystal in water to obtain a first solution; dissolving selenium powder in hydrazine hydrate at 30-50 DEG C to obtain a second solution, the concentration of the second solution being 0.025-0.1 mol / L; mixing the first solution and the second solution at a molar ratio of 1:1, and reacting at 180 DEG C for 8-14 hours to obtain a two-dimensional tellurium-selenium heterojunction.

2. The method for synthesis of two-dimensional TeSe heterojunction based on two-dimensional Te template according to claim 1, wherein, The two-dimensional tellurene crystal is provided by comprising: 0.1g of sodium tellurate and 0.5g of polyvinylpyrrolidone with a molecular weight of 55000 are dissolved in 30mL of deionized water with a conductivity of 18.2M Omega.cm to form a solution A with a concentration of 0.014mol / L, then 1.65mL of hydrazine hydrate and 3.3mL of ammonia are mixed to form solution B which is added to solution A, and then placed in a hydrothermal reaction container, sealed and reacted in an oven at 160 DEG C for 30 hours to obtain a product two-dimensional tellurene crystal.

3. The method of synthesis of two-dimensional tellurium selenium heterojunctions based on two-dimensional tellurium templates according to claim 1, characterized in that, The concentration of the second solution is 0.05mol / L.

4. The method for synthesis of two-dimensional TeSe heterojunction based on two-dimensional Te template according to claim 1, wherein, The selenium powder is dissolved in hydrazine hydrate at 40 DEG C.

5. The method of synthesis of two-dimensional tellurium selenium heterojunctions based on two-dimensional tellurium templates according to claim 1, wherein, The first solution and the second solution are reacted at 180 DEG C for 10 hours.

6. The method of synthesis of two-dimensional tellurium selenium heterojunctions based on two-dimensional tellurium templates according to claim 1, wherein, The synthesis method further comprises: the two-dimensional tellurium-selenium heterojunction is cleaned, and the cleaned two-dimensional tellurium-selenium heterojunction is transferred to a silicon wafer to observe the morphology and obtain the results of EDS energy spectrum analysis.

7. A two-dimensional tellurium-selenium heterojunction, characterized by The two-dimensional tellurium-selenium heterojunction is prepared by the synthesis method based on the two-dimensional tellurium template method according to any one of claims 1-5.

8. A field effect transistor, characterized by It comprises: a substrate with a back gate, a source and a drain are arranged on both sides of the upper surface of the substrate, and a two-dimensional tellurium-selenium heterojunction according to claim 6 is further arranged between the upper surface of the substrate and the source and the drain.

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