A tellurium-doped two-dimensional bismuth selenide oxide, a preparation method and application thereof

Abstract

The application belongs to the field of two-dimensional semiconductor material preparation, and particularly relates to a tellurium-doped two-dimensional selenium bismuth oxide and a preparation method and application thereof. The application takes a tube furnace as a reaction equipment, takes bismuth selenide, bismuth oxide and tellurium as raw materials, takes nitrogen as a carrier gas, and takes a fluorophlogopite sheet as a growth substrate, and a tellurium-doped two-dimensional selenium bismuth oxide is prepared by a chemical vapor deposition method. The tellurium-doped two-dimensional selenium bismuth oxide prepared by the method has a regular shape, a large size of more than 40 mu m, and can be applied to the preparation of a photoelectric detector, and has good photoelectric response performance and excellent environmental stability.

Description

Technical Field

[0001] This invention belongs to the field of two-dimensional semiconductor material preparation, specifically relating to a tellurium-doped two-dimensional bismuth selenide oxide, its preparation method, and its application. Background Technology

[0002] In a broad sense, two-dimensional (2D) materials are defined as materials in three-dimensional space where electrons can only move freely within a plane consisting of two dimensions smaller than 100 nm. 2D materials are characterized by a structure where the layers are coupled only by a very weak van der Waals bond, and their properties can change from an indirect bandgap to a direct bandgap as the number of layers decreases. Furthermore, 2D materials possess unique physical and optical properties such as ideal carrier mobility and strong light-matter coupling, exhibiting significant advantages and application potential in numerous material systems and thus receiving widespread use. However, inherent drawbacks such as the zero bandgap confinement of graphene, the poor stability of black phosphorus in air, and the large bandgap and insulating properties of hexagonal boron nitride severely limit their application in photoelectric detection devices.

[0003] Two-dimensional bismuth selenide oxide (Bi₂O₂Se) possesses environmental stability and high electron mobility, making it highly advantageous for applications in photodetectors. Doping intrinsic semiconductor materials with other elements can significantly improve their physical properties. However, due to the stable crystal structure of two-dimensional Bi₂O₂Se, it is difficult to achieve elemental doping using conventional methods. Therefore, the ability to fabricate doped two-dimensional Bi₂O₂Se with regular shapes (regular quadrilaterals), moderate sizes (side length greater than 40 μm), and moderate and uniform thickness (10–40 nm) is of great significance for the application of Bi₂O₂Se. Summary of the Invention

[0004] In order to overcome the shortcomings and disadvantages of the prior art, the primary objective of this invention is to provide a method for preparing tellurium-doped two-dimensional bismuth selenide oxide (Te-Bi2O2Se).

[0005] The second objective of this invention is to provide tellurium-doped two-dimensional bismuth selenide oxide prepared by the above-described method, which has moderate size, uniform thickness, and regular shape, and is a good semiconductor material.

[0006] Another object of the present invention is to provide the application of the above-mentioned tellurium-doped two-dimensional bismuth selenide oxide in two-dimensional semiconductor materials.

[0007] The objective of this invention is achieved through the following technical solution:

[0008] A method for preparing tellurium-doped two-dimensional bismuth selenide oxide includes the following steps:

[0009] (1) Bismuth selenide (Bi2Se3) and bismuth oxide (Bi2O3) were used as reaction sources, tellurium (Te) was used as a doping source, and fluorinated phlogopite sheets were used as growth substrates; then Bi2Se3, Bi2O3, Te and fluorinated phlogopite sheets were placed sequentially on a quartz boat;

[0010] (2) Place the quartz boat containing Bi2Se3, Bi2O3, Te and fluorinated phlogopite sheets in step (1) in the central constant temperature zone of the tube furnace, wherein Bi2O3 is in the center of the heating source.

[0011] (3) Open the inlet and outlet valves of the tubular furnace and introduce gas into the furnace tubes to remove air impurities. Among them, Bi2Se3 is upstream of the gas flow and fluorinated phlogopite sheets are downstream of the gas flow.

[0012] (4) Turn on the heating source of the tube furnace and heat it to 700℃ at a uniform heating rate of 20℃ / min. During the heating process, the gas flow rate is 20-40 sccm. Then, hold the temperature at 700℃ for 30 min. During the holding process, the gas flow rate is 95-105 sccm. After the holding process is completed, start cooling. During the cooling process, the gas flow rate is 20-40 sccm. When the temperature of the tube furnace drops to 90-100℃, turn off the gas flow. Tellurium-doped two-dimensional bismuth selenide oxide (Te-Bi2O2Se) is obtained.

[0013] The preferred mass ratio of Bi2Se3 to Bi2O3 in step (1) is 1:2;

[0014] The preferred amount of Te in step (1) is 5% of the mass of Bi2Se3;

[0015] The mass of Bi2Se3 in step (1) is 0.2g, the mass of Bi2O3 is 0.4g, and the mass of Te is 10mg;

[0016] The preferred size of the fluorophlogopite sheet mentioned in step (1) is 10mm × 10mm;

[0017] The distance between Bi2Se3 and Bi2O3 in step (1) is preferably 1 cm;

[0018] The preferred distance between Bi2O3 and Te in step (1) is 1 cm;

[0019] The distance between Te and the fluorinated phlogopite substrate in step (1) is 12 cm;

[0020] In step (2), it is preferable to plug both ends of the tube furnace with cotton to prevent the sample source in the quartz tube of the tube furnace from being blown into the ventilation pipe and blocked.

[0021] The gas mentioned in steps (3) and (4) is preferably nitrogen;

[0022] The preferred flow rate of the gas in step (3) is 120 sccm, and the preferred introduction time is 10 min;

[0023] A tellurium-doped two-dimensional bismuth selenide oxide was prepared by the above preparation method;

[0024] Applications of tellurium-doped two-dimensional bismuth selenide oxide in the field of semiconductor materials:

[0025] The semiconductor material is preferably a two-dimensional semiconductor photodetector;

[0026] The principle of this invention:

[0027] This invention uses bismuth selenide (Bi₂Se₃) and bismuth oxide (Bi₂O₃) as reaction sources, a small amount of tellurium (Te) as a dopant source, and fluorophlogopite as a growth substrate. Tellurium-doped two-dimensional bismuth selenide oxide (Te-Bi₂O₂Se) is deposited on a fluorophlogopite sheet using a tube furnace and a unidirectional gas flow chemical vapor deposition method. The size and thickness of the target Te-Bi₂O₂Se can be controlled by adjusting parameters such as the carrier gas flow rate, the reaction temperature and time of the reactants, and the distance between the reactants and the fluorophlogopite growth substrate. The Te-Bi₂O₂Se obtained by this invention has a regular square shape, a size of approximately 40–60 μm, uniform thickness, and has been tested and proven to be effective for use in semiconductor devices.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] (1) The operation steps of this invention are simple, the experimental equipment has a high safety factor, the samples required for the experiment are non-toxic or have very low toxicity, and the preparation efficiency is higher.

[0030] (2) The Te-Bi2O2Se nanosheets prepared by the present invention have Te elements uniformly doped in Bi2O2Se, have regular square features, and their size is about 40 to 60 μm with uniform thickness.

[0031] (3) The Te-Bi2O2Se nanosheets prepared by this invention have good photoelectric response performance and excellent environmental stability. Attached Figure Description

[0032] Figure 1 The image shows an optical microscope analysis of the Te-Bi2O2Se prepared in Example 1, where (a): scale bar is 50 μm, and (b): scale bar is 30 μm.

[0033] Figure 2This is an elemental mapping diagram of Te-Bi2O2Se obtained in Example 1, where (a): Bi element, (b): Te element, (c): O element, and (d): Se element.

[0034] Figure 3 This is the HAADF diagram of Te-Bi2O2Se obtained in Example 1.

[0035] Figure 4 These are device illustrations and photoelectric properties diagrams of the Te-Bi2O2Se prepared in Example 1, where (a): optical microscopy analysis of the device, (b): I... ds -V ds Curve (c): I of the device ds -T curve, (d): Response time curve of the device.

[0036] Figure 5 The image shows the device display and photoelectric properties of the Te-Bi2O2Se prepared in Comparative Example 1, where (a): optical microscopy analysis of the device, and (b): I-type properties of the device. ds -V ds curve.

[0037] Figure 6 The diagram shows the device display and photoelectric properties of the Te-Bi2O2Se prepared in Comparative Example 2, where (a): optical microscopy analysis of the device, and (b): I0 of the device. ds -V ds curve.

[0038] Figure 7 The diagram shows the device display and photoelectric properties of the Te-Bi2O2Se prepared in Comparative Example 3, where (a): optical microscopy analysis of the device, and (b): I0 of the device. ds -V ds curve.

[0039] Figure 8 The image shows the device display and photoelectric properties of the Te-Bi2O2Se prepared in Comparative Example 4, where (a): optical microscopy analysis of the device, and (b): I of the device. ds -V ds curve.

[0040] Figure 9 This is a diagram showing the positional relationship between the reactants Bi2Se3, Bi2O3, Te, and fluorophlogopite sheets. Detailed Implementation

[0041] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0042] Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art. Unless otherwise stated, the reagents, methods, and equipment used in this invention are conventional reagents, methods, and equipment in this technical field.

[0043] Example 1

[0044] (1) Weigh 0.4g Bi2O3, 0.2g Bi2Se3 and 10mg Te accurately on an electronic balance, and take a fresh fluorophlogopite sheet (10mm×10mm) for later use; then place Bi2Se3, Bi2O3, Te and fluorophlogopite sheet on a quartz boat in sequence.

[0045] (2) Place the quartz boat from step (1) in the central constant temperature zone of the tubular furnace tube in the order of Bi2Se3, Bi2O3, Te, and fluorinated phlogopite from right to left. The distance between Bi2Se3 and Bi2O3 and the distance between Bi2O3 and Te are 1 cm, the distance between Te and the fluorinated phlogopite is 12 cm, and Bi2O3 is placed at the center of the heating source. Figure 9 In addition, a wad of cotton is plugged into both ends of the furnace tube to prevent the sample source in the tubular furnace quartz tube from being blown into the ventilation pipe and blocked.

[0046] (3) Open the inlet and outlet valves of the tube furnace and introduce nitrogen gas at a flow rate of 120 sccm into the furnace tube for 10 minutes to remove air impurities. Among them, Bi2Se3 is upstream of the gas flow and fluorinated phlogopite sheets are downstream of the gas flow.

[0047] (4) Turn on the heating source of the tube furnace and heat it to 700°C at a heating rate of 20°C / min. The gas flow rate during the heating process is 35 sccm. Then, hold the temperature at 700°C for 30 min. The gas flow rate during the holding process is 100 sccm. After the holding process ends, start cooling. During the cooling process, the gas flow rate is 35 sccm. When the temperature of the tube furnace drops to 100°C, turn off the gas flow. When the temperature of the tube furnace drops to room temperature, take out the fluorinated phlogopite sheet to obtain tellurium-doped two-dimensional bismuth selenide oxide (Te-Bi2O2Se).

[0048] The morphology and properties of the Te-Bi2O2Se prepared in this embodiment are as follows:

[0049] (1) Figure 1 This is an optical microscope analysis of the Te-Bi2O2Se prepared in this embodiment. As can be seen from the figure, the Te-Bi2O2Se prepared in this embodiment is a regular quadrilateral with a side length greater than 40 μm.

[0050] (2) Figure 2 and Figure 3The figures show the elemental mapping diagram and HAADF diagram of the Te-Bi2O2Se prepared in this embodiment. As can be seen from the figures, the Te-Bi2O2Se prepared in this embodiment is uniformly doped and has no obvious defects.

[0051] (3) The Te-Bi2O2Se prepared in this embodiment was used to prepare optoelectronic devices according to the method provided in the reference (Lu Jianting. Novel Non-Layered Two-Dimensional Material In2S3: Material Growth, Device Fabrication and Photoresponse Characteristics [D]. Guangdong University of Technology). Figure 4 (a)), and then its photoelectric properties were detected under ambient temperature and pressure and laser irradiation at a wavelength of 405 nm.

[0052] in, Figure 4 (b) shows the device at different power densities (102.69, 82.12, 45.55, 3.43 mW / cm²). 2 ) and current-voltage (I) under dark conditions ds –V ds Characteristic curves, where the curves from bottom to top in the figure represent the conditions under dark conditions, 3.43 mW / cm², etc. 2 45.55mW / cm 2 82.12mW / cm 2 102.69mW / cm 2 As can be seen from the figure, the source-drain current (I) ds The photocurrent I increases significantly under light irradiation. ph (I ph =I light -I dark The current gradually increases with increasing light intensity, and the current can reach the milliampere level.

[0053] Figure 4 (c) is the device at V ds =1V, optical power density is 45.55mW / cm² 2 The photoresponse diagram under periodic incident light irradiation is shown below. During light irradiation, the device current rises sharply, demonstrating its sensitivity to light. When the light is blocked, the device current decreases rapidly. Therefore, it can be seen that the device fabricated in this embodiment exhibits clear switching characteristics and good repeatability.

[0054] Figure 4 (d) is the device at V ds =1V, optical power density 45.55mW / cm² 2 The response time is shown in the graph below. As can be seen from the graph, the Te-Bi2O2Se prepared in Example 1 has a response time of about 0.7s, achieving a fast response.

[0055] Example 2

[0056] Steps (1)-(3) are the same as in Example 1;

[0057] (4) Turn on the heating source of the tube furnace and heat it to 700°C at a heating rate of 20°C / min. The gas flow rate during the heating process is 20 sccm. Then, hold the temperature at 700°C for 30 min. The gas flow rate during the holding process is 95 sccm. After the holding process ends, start cooling. During the cooling process, the gas flow rate is 20 sccm. When the temperature of the tube furnace drops to 100°C, turn off the gas flow. When the temperature of the tube furnace drops to room temperature, take out the fluorinated phlogopite sheet to obtain tellurium-doped two-dimensional bismuth selenide oxide (Te-Bi2O2Se).

[0058] Example 3

[0059] Steps (1)-(3) are the same as in Example 1;

[0060] (4) Turn on the heating source of the tube furnace and heat it to 700°C at a heating rate of 20°C / min. The gas flow rate during the heating process is 40 sccm. Then, hold the temperature at 700°C for 30 min. The gas flow rate during the holding process is 105 sccm. After the holding process ends, start cooling. During the cooling process, the gas flow rate is 40 sccm. When the temperature of the tube furnace drops to 90°C, turn off the gas flow. When the temperature of the tube furnace drops to room temperature, take out the fluorinated phlogopite sheet to obtain tellurium-doped two-dimensional bismuth selenide oxide (Te-Bi2O2Se).

[0061] Comparative Example 1

[0062] The difference from Example 1 is that the distance between Te and the fluorophlogopite sheet is 9 cm. Other parameters are the same as in Example 1.

[0063] according to Figure 5 The optical micrograph (a) shows that the Te-Bi2O2Se prepared in this embodiment is a regular quadrilateral, but its side length is smaller than that of the Te-Bi2O2Se prepared in Example 1, less than 20 μm.

[0064] The optoelectronic device was prepared according to the method in Example 1, and its optoelectronic properties were examined. Figure 5 As shown in the photoelectric properties diagram (b), the photocurrent of the Te-Bi2O2Se device prepared in this embodiment is only at the microampere level, and its response to light intensity is not as obvious as that of the Te-Bi2O2Se device prepared in Example 1.

[0065] Comparative Example 2

[0066] The difference from Example 1 is that in step (4), the temperature is uniformly increased to 600°C at a heating rate of 20°C / min, and then held at 600°C for 30 min. Other parameters are the same as in Example 1.

[0067] The optoelectronic device was prepared according to the method in Example 1, and its optoelectronic properties were examined. Figure 6 As shown in the photoelectric properties diagram (b), the photocurrent of the Te-Bi2O2Se device prepared in this embodiment is only at the picoampere level, and the response to light intensity is extremely insignificant.

[0068] Comparative Example 3

[0069] The difference from Example 1 is that the heat preservation time in step (4) is 20 min, and the other parameters are the same as in Example 1.

[0070] The optoelectronic device was prepared according to the method in Example 1, and its optoelectronic properties were examined. Figure 7 The optical micrograph in (a) shows that the Te-Bi2O2Se prepared in Comparative Example 3 has an irregular quadrilateral shape and a side length that is smaller than that of the Te-Bi2O2Se prepared in Example 1, only about 30 μm.

[0071] according to Figure 7 As shown in the photoelectric properties diagram in (b), the photocurrent of the Te-Bi2O2Se device prepared in Comparative Example 3 is only at the picoampere level, and its response to light intensity is extremely insignificant.

[0072] Comparative Example 4

[0073] The difference from Example 1 is that the heating rate in step (4) is 25°C / min (5°C / min higher than that in Example 1), and the temperature is raised to 700°C after 28 minutes of uniform heating. Other parameters are the same as in Example 1.

[0074] The optoelectronic device was prepared according to the method in Example 1, and its optoelectronic properties were examined. Figure 8 As shown in the photoelectric properties diagram in (b), the photocurrent of the Te-Bi2O2Se device prepared in Comparative Example 4 is only at the picoampere level, and its response to light intensity is extremely insignificant.

[0075] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for preparing tellurium-doped two-dimensional bismuth selenide oxide, characterized in that... It includes the following steps: (1) Using Bi2Se3 and Bi2O3 as reaction sources, Te as doping source, and fluorinated phlogopite sheet as growth substrate; then Bi2Se3, Bi2O3, Te and fluorinated phlogopite sheet are placed sequentially on a quartz boat; (2) Place the quartz boat containing Bi2Se3, Bi2O3, Te and fluorinated phlogopite sheets in step (1) in the central constant temperature zone of the tube furnace, wherein Bi2O3 is in the center of the heating source; (3) Open the inlet valve and outlet valve of the tubular furnace and introduce gas into the furnace tube to remove air impurities. Among them, Bi2Se3 is upstream of the airflow and fluorinated phlogopite is downstream of the airflow. (4) Turn on the heating source of the tube furnace and heat it to 700℃ at a heating rate of 20℃ / min. During the heating process, the gas flow rate is 20~40 sccm. Then, hold the temperature at 700℃ for 30min. During the holding process, the gas flow rate is 95~105 sccm. After the holding is completed, start cooling. During the cooling process, the gas flow rate is 20~40 sccm. When the temperature of the tube furnace drops to 90~100℃, turn off the gas flow. Tellurium-doped two-dimensional bismuth selenide oxide is obtained. The distance between Bi2Se3 and Bi2O3 in step (1) is 1 cm; The distance between Bi2O3 and Te in step (1) is 1 cm; The distance between Te and the growth substrate fluorine mica sheet in step (1) is 12 cm.

2. The method for preparing tellurium-doped two-dimensional bismuth selenide oxide according to claim 1, characterized in that: The mass ratio of Bi2Se3 and Bi2O3 mentioned in step (1) is 1:

2.

3. The method for preparing tellurium-doped two-dimensional bismuth selenide oxide according to claim 1, characterized in that: The amount of Te used in step (1) is 5% of the mass of Bi2Se3.

4. The method for preparing tellurium-doped two-dimensional bismuth selenide oxide according to claim 1, characterized in that: The fluorophlogopite sheet mentioned in step (1) has a size of 10 mm × 10 mm.

5. The method for preparing tellurium-doped two-dimensional bismuth selenide oxide according to claim 1, characterized in that: The mass of Bi2Se3 in step (1) is 0.2 g, the mass of Bi2O3 is 0.4 g, and the mass of Te is 10 mg.

6. The method for preparing tellurium-doped two-dimensional bismuth selenide oxide according to claim 1, characterized in that: In step (2), cotton is stuffed into both ends of the tubular furnace.

7. The method for preparing tellurium-doped two-dimensional bismuth selenide oxide according to claim 1, characterized in that: The gas mentioned in steps (3) and (4) is nitrogen.

8. The method for preparing tellurium-doped two-dimensional bismuth selenide oxide according to claim 1, characterized in that: The gas flow rate in step (3) is 120 sccm and the inlet time is 10 min.

9. A tellurium-doped two-dimensional bismuth selenide oxide, characterized in that... It is prepared by the preparation method according to any one of claims 1-8.

10. The application of the tellurium-doped two-dimensional bismuth selenide oxide as described in claim 9 in the field of semiconductor materials.

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