Method for synchronously synthesizing two-dimensional cuprous telluride with two phase states

Abstract

The invention discloses a method for synchronously synthesizing two-dimensional cuprous telluride with two phase states, and belongs to the field of semiconductor material preparation. The preparation method comprises the following steps: by taking KCl as a transmission agent, adding GaTe and KCl into a quartz tube with a specific structure according to a molar ratio of 1: (0.5-0.8), vacuumizing the quartz tube to 10 <-1 > Pa, carrying out flame sealing on the quartz tube to form a high-vacuum environment in the quartz tube, and carrying out heating reaction to obtain the two-dimensional Cu2Te with two phase states. The preparation process is simple, the product has two different phase states, the thickness is small, the size is large, and the product has the characteristics of a P-type semiconductor and has great significance in promoting the development of electronics and optoelectronics.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor material preparation, specifically relating to a method for simultaneously synthesizing two-dimensional copper telluride in two phases. Background Technology

[0002] Two-dimensional Cu₂Te exhibits excellent conductivity and high carrier mobility due to its low Cu ion migration energy, attracting widespread attention from researchers. As a p-type semiconductor with good air stability, two-dimensional Cu₂Te shows significant advantages in complementary metal-oxide-semiconductor (CMOS) integration and optoelectronic devices. Therefore, developing fabrication techniques capable of precisely controlling its phase state is crucial for advancing this material towards practical application.

[0003] Currently, mainstream methods such as crystal exfoliation, chemical vapor deposition, and hydrothermal methods are all difficult to prepare Cu2Te in two phases by controlling experimental conditions. They often require cumbersome post-processing steps, which greatly restricts their application research. Summary of the Invention

[0004] The purpose of this invention is to provide a method for simultaneously synthesizing two-dimensional cuprous telluride in two phases, which can synthesize two-dimensional Cu2Te in tetragonal and hexagonal phases. The two-dimensional Cu2Te in the two phases obtained has a large size and semiconductor properties.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] The preparation methods for Cu₂Te in two different phases include the following steps:

[0007] (1) Weigh a certain amount of GaTe powder and KCl respectively, and place each raw material at the bottom of a quartz tube sealed at one end;

[0008] (2) Using mica as the growth substrate, cut Cu foil with the same length and width as mica and place it under mica and put it into a quartz tube together, so that mica and powder raw materials are separated by the neck of the quartz tube.

[0009] (3) Place a quartz column with a diameter slightly smaller than that of the quartz tube on the mica, use a molecular pump to evacuate the vacuum, and then use a flame gun to heat the quartz column to use the high temperature to fuse the quartz tube and the quartz column to achieve sealing, thereby creating a high vacuum growth environment inside the quartz tube.

[0010] (4) Place the flame-sealed quartz tube horizontally in a single-temperature zone tube furnace, with the bottom of the quartz tube aligned with the center of the tube furnace and the mica close to the end of the quartz column. After heating and reaction, Cu2Te in different phases is obtained.

[0011] Furthermore, the molar ratio of GaTe powder to KCl used in step (1) is 1:(0.5-0.8).

[0012] Furthermore, in step (2), the mica and copper foil are placed 13 cm away from the bottom of the quartz tube.

[0013] Furthermore, in step (3), a vacuum is drawn to 10. -1 Pa.

[0014] Furthermore, the heating reaction temperature in step (4) is 600-800 °C, the growth temperature is 500-600 °C, the heating rate is 10-20 °C / min, the heating time is 30-80 min, and the holding time is 5-40 min.

[0015] The two-dimensional Cu₂Te prepared by the above method has two phases and exhibits semiconductor properties, making it suitable for the fabrication of field-effect transistors, photodetectors, phototransistors, etc.

[0016] The significant advantages of this invention are:

[0017] (1) This invention uses chemical vapor transport method to successfully synthesize two-dimensional Cu2Te in different phases by controlling the heating rate, the distance between the growth substrate and the bottom of the quartz tube and the holding time. This process does not require complicated post-processing, and the phase of the product can be controlled by optimizing the holding time, which greatly simplifies the process, reduces energy consumption and material costs, and has good process controllability, repeatability and potential for large-scale production.

[0018] (2) The two phases of two-dimensional Cu2Te prepared by the present invention have semiconductor properties, which is of great significance to promoting the development of electronics and optoelectronics. Attached Figure Description

[0019] Figure 1 The diagram shows the reaction apparatus for simultaneously acquiring two phases of two-dimensional Cu2Te according to the present invention.

[0020] Figure 2 This is an optical microscope image of the two-dimensional Cu2Te prepared in Example 1 at 100x magnification.

[0021] Figure 3 This is an optical microscope image of the two-dimensional Cu₂Te obtained in Example 2 at 100x magnification. As can be seen from the optical microscope image, the obtained material has a rectangular shape.

[0022] Figure 4 The image shows a sample of hexagonal Cu2Te prepared in Example 1 and a transmission electron microscope image.

[0023] Figure 5 The images show a sample of tetragonal Cu2Te prepared in Example 2 and a transmission electron microscope image.

[0024] Figure 6 The image shows the Raman spectrum of the hexagonal Cu₂Te obtained in Example 1.

[0025] Figure 7 The image shows the Raman spectrum of the tetragonal Cu₂Te obtained in Example 2.

[0026] Figure 8 The IV curve was probed for a field-effect transistor made from hexagonal Cu2Te obtained in Example 1 at a source-drain voltage of 0.3V and a gate-source voltage of -25-25V.

[0027] Figure 9 The IV curve was probed for a field-effect transistor made from tetragonal Cu2Te obtained in Example 1 at a source-drain voltage of 0.5V and a gate-source voltage of -25-25V. Detailed Implementation

[0028] The preparation methods for two-dimensional Cu₂Te in different phases include the following steps:

[0029] (1) Weigh a certain amount of GaTe powder and KCl at a molar ratio of 1:(0.5-0.8) and place each raw material at the bottom of a quartz tube sealed at one end;

[0030] (2) Using mica as the growth substrate, place it and a copper foil cut to the same size as the mica into a quartz tube, so that the mica, copper foil and powder raw materials are separated by the constriction of the quartz tube, and the distance between the mica and the bottom of the quartz tube is 13cm.

[0031] (3) Place a quartz column with a diameter slightly smaller than that of the quartz tube close to the mica, and use a molecular pump to evacuate to 10. -1 Pa, then use a flame gun to seal the quartz column, thereby creating a high vacuum growth environment inside the quartz tube;

[0032] (4) Place the flame-sealed quartz tube horizontally in a single-temperature zone tube furnace, with the bottom of the quartz tube aligned with the center of the tube furnace and the mica close to the end of the quartz column. Heat at a rate of 10-20 °C / min, with the heating reaction temperature at 600-800 °C and the growth temperature at 500-600 °C (heating time controlled at 30-80 min). Then hold at this temperature for 5-40 min and allow to cool naturally to room temperature to obtain two-dimensional Cu2Te in two phases.

[0033] The reaction apparatus for simultaneously obtaining two phases of two-dimensional Cu2Te in this invention is shown in the figure below. Figure 1 As shown.

[0034] To make the content of this invention easier to understand, the technical solution of this invention will be further described below with reference to specific embodiments, but this invention is not limited thereto.

[0035] Example 1

[0036] (1) Weigh 10 mg GaTe and 5 mg KCl in sequence, and transport them to the bottom of the quartz tube through the transfer tube. Then add a clean mica substrate and copper foil 13 cm away from the bottom of the quartz tube, and separate the mica and powder raw materials through the neck of the quartz tube. Then put in a quartz column with a diameter slightly smaller than that of the quartz tube.

[0037] (2) Use a molecular pump to evacuate to 10 -1 Pa, then a hydrogen-oxygen flame gun was used to seal the quartz column, creating a high-vacuum growth environment inside the quartz tube;

[0038] (3) Place the flame-sealed quartz tube horizontally in a single-temperature zone tube furnace, so that the bottom of the quartz tube is aligned with the center of the tube furnace and the mica base is close to the end of the quartz column, i.e. the flame-sealed area.

[0039] (4) Heat at a rate of 10 °C / min until the temperature of the heating reaction is 700 °C and the growth temperature is 550 °C (heating time is controlled at 69 min). Then hold for 10 min and then cool naturally. The resulting phase on the mica substrate is a hexagonal phase with a transverse dimension of 10-20 μm.

[0040] The optical microscope image of the two-dimensional Cu2Te obtained in this embodiment at 100x magnification is shown below. Figure 2 As shown in the optical microscope image, the obtained material has a triangular shape.

[0041] The sample image of the hexagonal Cu₂Te and the transmission electron microscope image are as follows: Figure 4 As shown in the transmission electron microscope image, the obtained Cu2Te is hexagonal and has good crystallinity.

[0042] The Raman spectrum of the hexagonal Cu₂Te is as follows: Figure 6 As shown in the figure, the peak position of the hexagonal Raman peak is 90 cm. -1 121 cm -1 143 cm -1 This is largely consistent with reports in the literature, indicating that the hexagonal Cu2Te phase was successfully synthesized.

[0043] Example 2

[0044] (1) Weigh 10 mg GaTe and 5 mg KCl in sequence, and transport them to the bottom of the quartz tube through the transfer tube. Then add a clean mica substrate and copper foil 13 cm away from the bottom of the quartz tube, and separate the mica and powder raw materials through the neck of the quartz tube. Then put in a quartz column with a diameter slightly smaller than that of the quartz tube.

[0045] (2) Use a molecular pump to evacuate to 10 -1 Pa, then a hydrogen-oxygen flame gun was used to seal the quartz column, creating a high-vacuum growth environment inside the quartz tube;

[0046] (3) Place the flame-sealed quartz tube horizontally in a single-temperature zone tube furnace, so that the bottom of the quartz tube is aligned with the center of the tube furnace and the mica base is close to the end of the quartz column, i.e. the flame-sealed area.

[0047] (4) Heat at a rate of 10 °C / min until the temperature of the heating reaction is 700 °C and the growth temperature is 550 °C (heating time is controlled at 69 min), then hold for 40 min and then cool naturally. The resulting phase on the mica substrate is a tetragonal phase with a lateral dimension of 10-20 μm.

[0048] The optical microscope image of the two-dimensional Cu2Te obtained in this embodiment at 100x magnification is shown below. Figure 3 As shown in the optical microscope image, the obtained material has a rectangular shape.

[0049] The sample image of the tetragonal Cu₂Te and the transmission electron microscope image are as follows: Figure 5 As shown in the transmission electron microscope image, the obtained Cu2Te is a tetragonal phase with good crystallinity.

[0050] The Raman spectrum of the tetragonal Cu₂Te is as follows: Figure 7 As shown in the figure, the peak position of the tetragonal Raman peak is 92 cm. -1 123 cm -1 145 cm -1 This is largely consistent with reports in the literature, indicating that tetragonal Cu2Te was successfully synthesized.

[0051] Electrical performance testing:

[0052] The hexagonal and tetragonal two-dimensional Cu₂Te obtained in Example 1 and Experiment 2 were used to fabricate transistors and subjected to electrical tests. In the electrical tests, the IV curves were probed under conditions of a source-drain voltage of 0.3 V and a gate-source voltage of -1 to -1 V. Further analysis confirmed their semiconductor characteristics, and the results are as follows. Figure 8 and Figure 9 As shown.

[0053] The results showed that the hexagonal and tetragonal two-dimensional Cu₂Te obtained in Examples 1 and 2 respectively achieved carrier mobilities of 203.40 cm⁻¹. 2 / Vs and 53.08 cm 2 / Vs indicates that Cu2Te in different phases has high carrier mobility as a semiconductor, and Cu2Te exhibits P-type semiconductor characteristics, suggesting that it is promising for use in constructing high-performance electronic devices (such as field-effect transistors).

[0054] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made within the scope of the claims of the present invention should be included in the scope of the present invention.

Claims

1. A method for simultaneously synthesizing two-dimensional cuprous telluride in two phases, characterized in that, Includes the following steps: (1) Place GaTe powder and KCl powder at the bottom of a quartz tube that is sealed at one end; (2) Using mica as the growth substrate, cut Cu foil with a length and width equivalent to that of mica and place it under the mica and put it into the quartz tube together, so that the mica and the powder described in step (1) are separated by the neck of the quartz tube. (3) Place a quartz column with a diameter slightly smaller than that of the quartz tube close to the mica, evacuate the vacuum and then perform flame sealing to create a high vacuum growth environment inside the quartz tube. (4) Place the flame-sealed quartz tube horizontally in a single-temperature zone tube furnace, with the bottom of the quartz tube aligned with the center of the tube furnace and the mica close to the end of the quartz column. After heating and reaction, keep it at the temperature for different times within the growth temperature range to obtain the two-dimensional Cu2Te in different phases.

2. The method according to claim 1, characterized in that: The molar ratio of GaTe powder to KCl used in step (1) is 1:(0.5-0.8).

3. The method according to claim 1, characterized in that: In step (2), the mica and Cu foil are placed 13 cm away from the bottom of the quartz tube.

4. The method according to claim 1, characterized in that: In step (3), a vacuum is drawn to 10. -1 Pa.

5. The method according to claim 1, characterized in that: The heating reaction in step (4) is carried out at a temperature of 600-800 °C, the growth temperature is 500-600 °C, the heating rate is 10-20 °C / min, and the holding time is 5-40 min.

6. A two-dimensional Cu₂Te in different phases prepared by the method of any one of claims 1-5.

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