One-dimensional GaSe nanobelt and preparation method thereof

Abstract

The invention discloses a one-dimensional GaSe nanobelt and a preparation method thereof, and belongs to the technical field of nano material growth. GaSe powder and Ga metal are mixed and placed in a first temperature zone of a tubular furnace, and a substrate is placed on a high-temperature-resistant plate to form a laminated body which is placed in a second temperature zone. Then the tubular furnace is vacuumized to be lower than 0.1 Pa, protective gas is introduced for purging, and the pressure intensity is maintained to be 1 atm; and heating the first temperature zone and the second temperature zone to 900-960 DEG C and 600-750 DEG C respectively, vacuumizing the tubular furnace to be lower than 0.1 Pa, and introducing protective gas for material growth to obtain the one-dimensional GaSe nanobelt. According to the method, the metal source containing GaSe and Ga is used as a precursor, at a high temperature, other metals do not need to be added as a catalyst, the metal source volatilizes and diffuses to the substrate in the second temperature zone to obtain the high-quality nanobelt, and the growth density and length of NWs are controllable by regulating and controlling the concentration of the metal source, the flow of carrier gas and the distance between the metal source and the substrate; a new thought is provided for the preparation of the one-dimensional nano material.

Description

Technical Field

[0001] The invention belongs to the technical field of nano material growth, and in particular relates to a one-dimensional GaSe nanobelt and a preparation method thereof. Background Art

[0002] As an important III-VI semiconductor material, GaSe is known for its high carrier mobility, suitable optical band gap, nonlinear optical properties and excellent light response characteristics. In the field of optics, GaSe has high optical transmittance in the visible and near-infrared regions, and can be used to make optical components such as optical windows and lenses. It also has a strong second-order nonlinear optical effect and can play a role in nonlinear optical devices such as laser frequency conversion and optical switches. In the electrical field, as a semiconductor material, it has a moderate band gap width and high carrier mobility, and has certain application potential in field effect transistors, photodetectors, etc. In addition, GaSe also shows potential application prospects in other fields such as flexible electronics and energy conversion.

[0003] However, there are some problems with the existing preparation methods. Although the hydrothermal method is relatively simple to operate, low in cost and can regulate the size and morphology of nanobelts, it needs to be carried out under high pressure and the purity and crystallinity of the product are poor. Although the molecular beam epitaxy (MBE) method can prepare high-quality ultra-thin nanobelts and can accurately control the thickness and composition, the equipment is expensive, the operation is complicated, the growth rate is slow, and the yield is low. The mechanical exfoliation method has irregular morphology, low yield and serious time consumption. The morphology of nanobelts has an important influence on their performance and application. The existing synthesis method is difficult to obtain one-dimensional gallium selenide nanomaterials with high growth density. There are also disadvantages such as complex procedures, high costs, long growth cycles, low quality, and poor universality, which poses a challenge to the need to integrate more transistors on chips to achieve complex functions. Therefore, obtaining a large number of high-quality GaSe nanobelts in a simple way, especially considering the quantum confinement effect and unique physical and chemical properties brought about by the reduction of material dimensions, has become a key issue in the current development of science and technology. Summary of the invention

[0004] In view of the above-mentioned shortcomings of the prior art, the present invention provides a one-dimensional GaSe nanoribbon and a preparation method thereof.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] The preparation method of one-dimensional GaSe nanoribbon comprises the following steps:

[0007] (1) GaSe powder and Ga metal are mixed and placed in the first temperature zone of a tube furnace, a substrate is placed on a high temperature resistant plate to form a laminate, and the laminate is placed in the second temperature zone of the tube furnace;

[0008] (2) After the tube furnace is evacuated to a pressure below 0.1 Pa, a protective gas is introduced for purging, and then the pressure is maintained at 1 atm;

[0009] (3) controlling the first temperature zone and the second temperature zone to heat up to 900-960° C. and 600-750° C. respectively, and then evacuating the tube furnace to a pressure lower than 0.1 Pa, and introducing a protective gas to grow the material;

[0010] (4) After the growth is completed, the heating power is turned off, the protective gas flow rate is maintained unchanged, and the mixture is cooled to room temperature to obtain a one-dimensional GaSe nanoribbon.

[0011] As a preferred embodiment of the present invention, the mass ratio of GaSe powder to Ga metal is controlled to be (1.5-2):1. If it is not within this range, only particles can be grown on the substrate and GaSe nanobelts cannot be grown.

[0012] As a preferred embodiment of the present invention, in step (2), the protective gas is 500-1000 sccm of gas A and 40-100 sccm of hydrogen; gas A is argon or nitrogen.

[0013] As a preferred embodiment of the present invention, in the step (2), the purging time is 10-30 minutes.

[0014] As a preferred embodiment of the present invention, in step (3), the protective gas is 50-100 sccm of gas B and 5-10 sccm of hydrogen; gas B is argon or nitrogen.

[0015] As a preferred embodiment of the present invention, in the step (2), the material growth time is 2-30 minutes.

[0016] As a preferred embodiment of the present invention, the substrate is SiO 2 Substrate, sapphire, fused quartz or mica sheet; the high temperature resistant plate is a quartz plate.

[0017] As a preferred embodiment of the present invention, the substrate is repeatedly rinsed with ethanol and rinsed with a high-speed argon gas flow before use.

[0018] The present invention also claims to protect the one-dimensional GaSe nanoribbon prepared by the method for preparing the one-dimensional GaSe nanoribbon.

[0019] Compared with the prior art, the present invention has the following beneficial effects: the present invention places a metal source containing GaSe and Ga in a specific temperature zone of a tube furnace as a precursor. At high temperature, without adding a metal catalyst, the mixture volatilizes and diffuses to the substrate in the second temperature zone to obtain high-quality nanobelts, and the growth density and length of NWs can be controlled by adjusting the concentration of the metal source, the flow rate of the carrier gas, and the distance between the metal source and the substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the growth process of GaSe nanoribbons of the present invention.

[0021] Figure 2 This is a SEM morphology image of the GaSe nanobelt prepared in Example 1 of the present invention.

[0022] Figure 3 This is a local SEM morphology image of the GaSe nanobelt prepared in Example 1 of the present invention.

[0023] Figure 4 These are the Raman spectrum and fluorescence spectrum of the GaSe nanobelt sample of Example 1 of the present invention; a is the Raman spectrum; b is the fluorescence spectrum.

[0024] Figure 5 It is a SEM morphology image of the GaSe nanobelt sample of Example 2 of the present invention and a corresponding scanning distribution image of Ga and Se elements.

[0025] Figure 6 These are the SEM morphology images and EDS spectra of the GaSe nanobelts prepared in Example 3 of the present invention; wherein a is the SEM morphology image, and b is the EDS spectrum.

[0026] Figure 7 The SiO prepared in Comparative Example 1 of the present invention 2 SEM images of the materials on the substrate.

[0027] Figure 8 The SiO prepared in Comparative Example 3 of the present invention 2 SEM images of materials on substrate, a is a low-magnification SEM image of the material; b is a high-magnification SEM image of the material. DETAILED DESCRIPTION

[0028] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0029] Figure 1 Schematic diagram of the device for preparing GaSe nanoribbons according to the present invention, Figure 1As shown, the device includes a high-temperature tube furnace, in which a first temperature zone and a second temperature zone with different heating temperatures are arranged. In the present invention, a protective gas is introduced into the tube furnace, and the first temperature zone and the second temperature zone are sequentially arranged along the gas flow direction of the protective gas. The first temperature zone has a temperature of 900 to 960° C., and the second temperature zone has a temperature of 600 to 750° C. The protective gas can also be used as a carrier gas at the same time, and the protective gas is argon or nitrogen and hydrogen.

[0030] Example 1

[0031] The preparation method of one-dimensional GaSe nanoribbon comprises the following steps:

[0032] (1) 80 mg of Ga metal was dispersed into multiple spherical small particles through a quartz "sieve" with a pore size of 0.5 mm and a pore spacing of 5 mm, so that it covered 120 mg of GaSe powder. The mixture of Ga metal and GaSe powder was placed in the first temperature zone of a tube furnace. 1×1 cm SiO 2 The substrate is then flushed with high-speed argon and placed on a high-temperature resistant quartz plate to form a stack, which is placed in the second temperature zone of a tube furnace, with the substrate 12 cm away from the Ga and GaSe mixture.

[0033] (2) After the tube furnace is evacuated to a pressure below 0.1 Pa, 500 sccmAr+40 sccm hydrogen is introduced to flow through the Ga and GaSe powder mixture and the stack for 10 minutes, and then the inlet valve and outlet valve are closed to maintain the pressure in the tube at 1 atm. Then the heating rate is controlled to increase the temperature of the first temperature zone to 900°C and the second temperature zone to 690°C at a temperature increase rate of 22°C / min, and then the vacuum pump is turned on until the pressure in the tube furnace is below 0.1 Pa, and 50 sccmAr+5 sccmH is introduced. 2 , keep warm and grow for 5 minutes.

[0034] (3) After the growth is completed, turn off the heating power supply, maintain the Ar gas flow rate unchanged, and cool to room temperature to obtain clean SiO 2 GaSe nanoribbon samples on substrate. Figure 2 As shown in FIG. 1 , zigzag and straight-line GaSe nanoribbons are generated on the substrate of Example 1. Figure 3 As shown in Figure 1, the scanning electron microscope (SEM) image of a single GaSe nanoribbon shows that the width of the GaSe nanoribbon is uniform and the surface is smooth. Figure 4 As shown in Figure a, the Raman spectrum of a single GaSe nanoribbon at room temperature is shown in Figure a. -1 , 209.7cm -1 , 233.2cm -1 and 303.5cm -1 Four characteristic peaks corresponding to the A1 1g ,E 1 2g ,E 2 1g and A 2 1g Vibration mode. 1 2g and E 2 1g Corresponding to the vibration modes in the plane, the two A 1g Corresponding to the out-of-plane vibration mode. Figure b is the photoluminescence spectrum of a single GaSe nanoribbon at room temperature, with a luminescence peak at 619nm (2eV). The half-width of the luminescence peak is about 10nm, which is relatively small. The grown GaSe nanoribbon exhibits excellent optical properties, and the crystal quality of the material is very good.

[0035] Example 2

[0036] The preparation method of one-dimensional GaSe nanoribbon comprises the following steps:

[0037] (1) 100 mg of Ga metal was dispersed into multiple spherical small particles through a quartz "sieve" with a pore size of 0.5 mm and a pore spacing of 5 mm, so that it covered 170 mg of GaSe powder. The mixture of Ga metal and GaSe powder was placed in the first temperature zone of a tube furnace. 1×1 cm SiO 2 The substrate is then flushed with high-speed argon and placed on a high-temperature resistant quartz plate to form a stack, which is placed in the second temperature zone of a tube furnace, with the substrate 12 cm away from the Ga and GaSe mixture.

[0038] (2) After the tube furnace is evacuated to a pressure below 0.1 Pa, 500 sccmAr+40 sccm hydrogen is introduced to flow through the Ga and GaSe powder mixture and the stack for 10 minutes, and then the inlet valve and outlet valve are closed to maintain the pressure in the tube at 1 atm. Then the heating rate is controlled to increase the temperature of the first temperature zone to 930°C and the second temperature zone to 710°C at a temperature increase rate of 20°C / min, and then the vacuum pump is turned on until the pressure in the tube furnace is lower than 0.1 Pa, and 50 sccmAr+5 sccmH is introduced. 2 , keep warm and grow for 2 minutes.

[0039] (3) After the growth is completed, turn off the heating power supply, maintain the Ar gas flow rate unchanged, and cool to room temperature to obtain clean SiO 2 GaSe nanoribbon samples on substrate. Figure 5 As shown, Ga and Se elements are evenly distributed on the GaSe nanobelts, which also indicates that the structure of the grown material is very uniform.

[0040] Example 3

[0041] The preparation method of one-dimensional GaSe nanoribbon comprises the following steps:

[0042] (1) 100 mg of Ga metal was dispersed into multiple spherical small particles through a quartz "sieve" with a pore size of 0.5 mm and a pore spacing of 5 mm, so that it covered 200 mg of GaSe powder. The mixture of Ga metal and GaSe powder was placed in the first temperature zone of a tube furnace. 1×1 cm SiO 2 The substrate is then flushed with high-speed argon and placed on a high-temperature resistant quartz plate to form a stack, which is placed in the second temperature zone of a tube furnace, with the substrate 12 cm away from the Ga and GaSe mixture.

[0043] (2) After the tube furnace is evacuated to a pressure below 0.1 Pa, 500 sccmAr+40 sccm hydrogen is introduced to flow through the Ga and GaSe powder mixture and the stack for 10 minutes, and then the inlet valve and outlet valve are closed to maintain the pressure in the tube at 1 atm. Then the heating rate is controlled to increase the temperature of the first temperature zone to 960°C and the second temperature zone to 750°C at a temperature increase rate of 20°C / min, and then the vacuum pump is turned on until the pressure in the tube furnace is below 0.1 Pa, and 50 sccmAr+5 sccmH is introduced. 2 , keep warm and grow for 30 minutes.

[0044] (3) After the growth is completed, turn off the heating power supply, maintain the Ar gas flow rate unchanged, and cool to room temperature to obtain clean SiO 2 GaSe nanoribbon samples on substrate. Figure 6 As shown, the nanobelts have uniform width and smooth surface. At the same time, the EDS spectrum shows that the nanobelts contain only two elements, Ga and Se, and their ratio is close to 1:1, indicating that the stoichiometric ratio of the synthesized nanobelts is 1:1, that is, GaSe.

[0045] Comparative Example 1

[0046] A method for preparing a GaSe material comprises the following steps:

[0047] (1) 80 mg of Ga metal was dispersed into multiple spherical small particles through a quartz "sieve" with a pore size of 0.5 mm and a pore spacing of 5 mm, so that it covered 120 mg of GaSe powder. The mixture of Ga metal and GaSe powder was placed in the first temperature zone of a tube furnace. 1×1 cm SiO 2 The substrate is then flushed with high-speed argon and placed on a high-temperature resistant quartz plate to form a stack, which is placed in the second temperature zone of a tube furnace, with the substrate 12 cm away from the Ga and GaSe mixture.

[0048] (2) After the tube furnace is evacuated to a pressure below 0.1 Pa, 500 sccmAr+40 sccm hydrogen is introduced to flow through the Ga and GaSe mixture and the stack for 10 minutes, and then the inlet valve and outlet valve are closed to maintain the pressure in the tube at 1 atm. Then the heating rate is controlled to increase the temperature of the first temperature zone to 850°C and the second temperature zone to 660°C at 22°C / min, and then the vacuum pump is turned on until the pressure in the tube furnace is below 0.1 Pa, and 50 sccmAr+5 sccmH is introduced. 2 , keep warm and grow for 5 minutes.

[0049] (3) After the growth is completed, turn off the heating power supply, maintain the Ar gas flow rate unchanged, and cool to room temperature to obtain clean SiO 2 GaSe nanoribbon samples on substrate. Figure 7 As shown, in SiO 2 No GaSe nanoribbons were observed on the substrate.

[0050] Comparative Example 2

[0051] A method for preparing a GaSe material comprises the following steps:

[0052] (1) 120 mg of GaSe powder was placed in the first temperature zone of a tube furnace. 1×1 cm SiO 2 The substrate is then flushed with high-speed argon gas and placed on a high-temperature resistant quartz plate to form a stack, which is placed in the second temperature zone of the tube furnace with the substrate 12 cm away from the GaSe powder.

[0053] (2) After the tube furnace is evacuated to a pressure below 0.1 Pa, 500 sccm Ar + 40 sccm hydrogen is introduced to flow through the GaSe powder and the stack for 10 minutes, and then the inlet valve and outlet valve are closed to maintain the pressure in the tube at 1 atm. Then the heating rate is controlled to increase the temperature of the first temperature zone to 900°C and the second temperature zone to 690°C at a temperature increase rate of 22°C / min, and then the vacuum pump is turned on until the pressure in the tube furnace is below 0.1 Pa, and 50 sccm Ar + 5 sccm H is introduced. 2 , keep warm and grow for 5 minutes.

[0054] (3) After the growth is completed, turn off the heating power supply, maintain the Ar gas flow rate unchanged, and cool to room temperature. 2 Some small particles were generated on the substrate, but no material with nanoribbon morphology was found.

[0055] Comparative Example 3

[0056] A method for preparing a GaSe material comprises the following steps:

[0057] (1) 80 mg of Ga metal was dispersed into multiple spherical small particles through a quartz "sieve" with a pore size of 0.5 mm and a pore spacing of 5 mm, so that it was covered with 120 mg of Na 2 Se powder, Ga metal and Na 2 The mixture of Se powder is placed in the first temperature zone of the tube furnace. The 1×1 cm SiO2 substrate is repeatedly cleaned with ethanol, then flushed with high-speed argon gas, and placed on a high-temperature quartz plate to form a stack. The stack is placed in the second temperature zone of the tube furnace, and the substrate is 1.5 meters away from the Ga metal and Na 2 Se mixture 12cm.

[0058] (2) After the tube furnace is evacuated to a pressure below 0.1 Pa, 500 sccm Ar + 40 sccm hydrogen is introduced to flow through the Ga metal and Na 2 The Se mixture and the stack were purged for 10 min, and then the inlet and outlet valves were closed to maintain the pressure in the tube at 1 atm. The temperature was then raised to 900°C in the first temperature zone and 690°C in the second temperature zone at a heating rate of 22°C / min. The vacuum pump was then turned on until the pressure in the tube furnace was lower than 0.1 Pa, and 50 sccmAr+5 sccmH was introduced. 2 , keep warm and grow for 5 minutes.

[0059] (3) After the growth is completed, turn off the heating power, maintain the Ar gas flow rate unchanged, and cool to room temperature. Figure 8 As shown, SiO 2 Some small particles gathered on the substrate, and no material with nanobelt morphology was found.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A method for preparing a one-dimensional GaSe nanoribbon, characterized in that: The steps include: (1) GaSe powder and Ga metal are mixed and placed in the first temperature zone of a tube furnace, a substrate is placed on a high temperature resistant plate to form a laminate, and the laminate is placed in the second temperature zone of the tube furnace; (2) After the tube furnace is evacuated to a pressure below 0.1 Pa, a protective gas is introduced for purging, and then the pressure is maintained at 1 atm; (3) controlling the first temperature zone and the second temperature zone to heat up to 900-960° C. and 600-750° C. respectively, and then evacuating the tube furnace to a pressure lower than 0.1 Pa, and introducing a protective gas to grow the material; (4) After the growth is completed, the heating power is turned off, the protective gas flow rate is maintained unchanged, and the mixture is cooled to room temperature to obtain a one-dimensional GaSe nanoribbon.

2. The method for preparing the one-dimensional GaSe nanoribbon according to claim 1, characterized in that: The mass ratio of the GaSe powder to Ga metal is (1.5-2):

1.

3. The method for preparing a one-dimensional GaSe nanoribbon according to claim 1, characterized in that: In the step (2), the protective gas is 500-1000 sccm of gas A and 40-100 sccm of hydrogen; gas A is argon or nitrogen.

4. The method for preparing a one-dimensional GaSe nanoribbon according to claim 1, characterized in that: In the step (2), the purging time is 10-30 minutes.

5. The method for preparing a one-dimensional GaSe nanoribbon according to claim 1, characterized in that: In the step (3), the protective gas is 50-100 sccm of gas B and 5-10 sccm of hydrogen; gas B is argon or nitrogen.

6. The method for preparing a one-dimensional GaSe nanoribbon according to claim 1, characterized in that: In the step (2), the material growth time is 2-30 minutes.

7. The method for preparing a one-dimensional GaSe nanoribbon according to claim 1, characterized in that: The substrate is a SiO2 substrate, sapphire, fused quartz or mica sheet; the high temperature resistant plate is a quartz plate.

8. The method for preparing a one-dimensional GaSe nanoribbon according to claim 1, characterized in that: The substrate was rinsed repeatedly with ethanol and flushed with a high-speed argon stream before use. 9 . The one-dimensional GaSe nanoribbon prepared by the method for preparing the one-dimensional GaSe nanoribbon according to claim 1 .

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