CN106966384A - A kind of preparation method of molybdenum disulfide/graphene stratiform assembly - Google Patents

Abstract

The invention relates to a method for preparing a molybdenum disulfide/graphene layered assembly. A single quartz tube is used to cooperate with a tube furnace with double heating furnaces; a SiO ₂ /Si substrate transferred with a graphene film is placed in a place Above the container of molybdenum trioxide powder, place the container with sulfur powder in the center of the first heating furnace of the tube furnace; place the container of molybdenum trioxide in the center of the second heating furnace of the tube furnace; Enter argon; under the argon atmosphere, the internal pressure of the tube furnace is emphasized to 133.29Pa, the first heating zone is heated up to the volatilization temperature of sulfur powder, and the second heating zone is heated up to the volatilization temperature of molybdenum trioxide; the disulfide Molybdenum is deposited on the substrate and then cooled to room temperature to obtain a molybdenum disulfide/graphene layered assembly. It has the characteristics of large area and high quality, the light intensity is 94μW/cm ² , the photocurrent density reaches 3.0μA/cm ² , and the photocurrent response is completed within 2.3s at the moment of light on-off; it has a good application prospect.

Description

A kind of preparation method of molybdenum disulfide/graphene layer assembly

technical field

The invention relates to a method for preparing a molybdenum disulfide/graphene layered assembly, belonging to the field of semiconductor film material preparation.

Background technique

The two-dimensional layered materials molybdenum disulfide and graphene have strong electron-hole confinement, flexibility, and high transparency due to their unique planar structures, making them thinner, more flexible, and high-performance in the next generation. The field of optoelectronic devices has a wide range of applications. However, the phototransistor prepared by molybdenum disulfide alone has a low photoresponse of 7.5mA/W, which is due to the low carrier mobility of molybdenum disulfide, and the Schottke formed between molybdenum disulfide and the electrode in the device. The effect of the base junction (regulated by the electrode material). And because the absorbance of graphene is only 2.3% of visible light, the photoresponse of a photodetector made of graphene alone is only 6.1mA W ^-1 , which greatly limits the application of graphene in the field of optoelectronic devices. In view of this, the focus is on the use of molybdenum disulfide/graphene layered composites to enhance the photoresponse of phototransistors. Using the photoselectivity of molybdenum disulfide and the high carrier mobility properties of graphene, molybdenum disulfide is used for light absorption, and graphene is used as a channel for carrier migration to improve photoresponse. Therefore, the present invention combines _two materials of graphene and MoS2 to form a new type of heterojunction device, which combines the sensitivity of MoS2 to light and the excellent electrical properties of graphene, complements the advantages of the _two materials, and promotes the development of graphite. Extensive applications of alkenes and _MoS2 in electronics.

There are three main methods to prepare molybdenum disulfide/graphene layered composites: hydrothermal synthesis, physical assembly, and chemical vapor deposition. Both the hydrothermal synthesis method and the physical assembly method have their own advantages and disadvantages. Among them, the molybdenum disulfide/graphene layered composite material prepared by the hydrothermal synthesis method has small and uneven sheets, and the morphology cannot be effectively controlled. The efficiency is low, and the process is various and the operation is complicated, which is not conducive to industrial mass production; the sheets of the molybdenum disulfide/graphene layered assembly prepared by the physical assembly method are only micron, which is not conducive to the integration and industrialization of optoelectronic devices. The impurities introduced during the physical assembly transfer process and the weak van der Waals force between molybdenum disulfide and graphene layers will affect its photoelectric performance. However, the preparation of molybdenum disulfide/graphene layered assembly by chemical vapor deposition is to directly grow molybdenum disulfide on a large-area graphene film. Graphene can be produced on a large scale, and the crystallinity of the obtained complex and the quality of molybdenum disulfide can be well controlled.

However, although the molybdenum disulfide/graphene layered assembly prepared by the chemical vapor phase method has a relatively large area, it still has the defects of poor crystallization performance and low crystal quality of molybdenum disulfide. This will definitely affect the performance of the assembled body in the field of optoelectronic devices. Among them, factors affecting the crystallization quality of the bilayer molybdenum disulfide/graphene layered assembly include: the mass ratio of molybdenum source to sulfur source, preparation pressure, preparation temperature, carrier gas flow rate, heating rate, etc. Through a series of experimental explorations and optimization of the experimental process, the optimal preparation pressure, temperature, carrier gas flow rate, and heating rate for the preparation of layered assemblies were obtained. The invention realizes the controllable preparation of two-layer molybdenum disulfide/graphene and three-layer molybdenum disulfide/graphene layered assembly by adjusting the mass ratio of molybdenum source and sulfur source.

The invention adopts a chemical vapor deposition method to prepare a double-layer molybdenum disulfide/graphene layered assembly, and prepares a large-area, high-quality composite assembly. On the whole, the chemical vapor deposition method is an excellent means for the controllable preparation of molybdenum disulfide/graphene layered assemblies and the realization of their integrated applications in the field of optoelectronic devices.

Contents of the invention

The object of the present invention is to provide a kind of preparation method of molybdenum disulfide/graphene layer assembly, on the SiO ₂ /Si substrate that is transferred with graphene film, prepare double-layer molybdenum disulfide by chemical vapor deposition, just obtain Bilayer molybdenum disulfide/graphene layered assemblies. The semiconductor material prepared by the method has excellent photoelectric conversion and photocurrent response properties.

The present invention is achieved through the following technical solutions:

A preparation method of molybdenum disulfide/graphene layered assembly, comprising the following processes:

(1) Adopt single quartz tube, cooperate the tubular furnace of double heating furnace; SiO ₂ /Si substrate that will be transferred with graphene film, be placed on the container top that is placed molybdenum trioxide powder, will be placed the container that sulfur powder is placed In the center of the first heating furnace of the tube furnace; then place the container with molybdenum trioxide in the center of the second heating furnace of the tube furnace; feed argon;

(2) Under the argon atmosphere, the internal pressure of the tube furnace is emphasized to 133.29Pa, the first heating zone is heated up to the volatilization temperature of the sulfur powder, and the second heating zone is heated up to the volatilization temperature of the molybdenum trioxide; the molybdenum disulfide Deposited on the substrate and then cooled to room temperature, a molybdenum disulfide/graphene layered assembly is obtained.

The preferred volatilization temperature of sulfur powder is 160°C

The preferred volatilization temperature of molybdenum trioxide is 650°C

Preferably, the length of the SiO ₂ /Si substrate is not greater than 1 cm, the width is not greater than 1 cm, and the thickness is 0.5 mm.

Preferably, the container with molybdenum trioxide powder is a boat-shaped porcelain boat.

The preferred boat-shaped porcelain boat is 6cm long, 3cm wide, and 1cm deep.

Preferably, the mass ratio of molybdenum trioxide to sulfur powder is 1-3:100.

The specific description is as follows: the following does not limit the only method, and graphene films prepared by other methods are applicable to the present invention.

A kind of preparation method of molybdenum disulfide/graphene layer assembly of the present invention comprises the following processes:

1. Preparation and transfer of graphene

(1) Copper foil substrate pretreatment: Cut the copper foil into a certain size, put it in a certain concentration of acetic acid solution, acetone reagent, and ethanol reagent for ultrasonic treatment for a period of time, and then store it in acetone for later use;

(2) prepare graphene: put the treated copper foil into the tube furnace, set the heating program, first pass into the argon of 500sccm, the air in the tube furnace is exhausted; then mix in argon 300sccm and hydrogen 100sccm Raise to 1030-1050°C under atmosphere and keep for 30-40min. Then cool down, feed methane with a gas flow rate of 0.6-0.8 sccm, accompanied by a certain gas flow rate of argon gas 1000 sccm and hydrogen gas 10 sccm, and keep it for 20 minutes; finally, quickly drop to room temperature under an argon gas flow rate of 300 sccm to obtain a large-area graphene film;

(3) Transfer of graphene: configure the PMMA solution of 10mg/ml, then spin-coat the above-mentioned graphene film with a desktop glue spreader; bake the spin-coated sample at 150°C for 10-20min to solidify the PMMA; Use 20mg/ml sodium hydroxide solution as the electrolyte, the anode is metal platinum, and the cathode is graphene/copper foil coated with PMMA. The applied voltage is set to -5 to -6V, and hydrogen is generated on the surface of the copper foil by electrochemical reaction. , peel the PMMA/graphene film off the surface of the copper foil, wash the PMMA/graphene film in deionized water; cut the cleaned sample and place it on the SiO ₂ /Si substrate, dry it and bake it at 120°C Bake for 15 minutes to strengthen the bonding force between PMMA and the substrate, then soak in acetone, isopropanol, and chloroform for 10 minutes, remove the PMMA film, and then dry it with nitrogen, and finally successfully transfer the graphene to the new SiO ₂ /Si substrate (length not greater than 1cm, width not greater than 1cm, thickness 0.5mm).

2. Preparation method of molybdenum disulfide/graphene layered assembly

(1) Place the SiO ₂ /Si substrate transferred with a graphene film directly above the ship-shaped high-temperature-resistant container with a certain quality of molybdenum trioxide powder, and place the ship-shaped high-temperature-resistant container with a certain quality of sulfur powder on the tube The center of the first heating furnace of the type furnace (the amount of sulfur powder is 500mg, the mass ratio of molybdenum trioxide to sulfur powder is 1-3:100. 1:100 mass ratio can get 2 layers of molybdenum disulfide, 3:100 mass ratio specific energy to obtain 3 layers of molybdenum disulfide); then put a container with a certain quality of molybdenum trioxide on the second heating furnace center of the tube furnace; before starting to heat up, feed a certain amount of argon to exhaust the air in the quartz tube;

(2) Then under the argon atmosphere, the internal pressure of the tube furnace is emphasized to 133.29Pa, the temperature of the first heating zone is raised to 160°C, and the temperature of the second heating zone is raised to 650°C (keep the two heating zones at the same temperature during the heating process) time, rise to the corresponding temperature, and the heating time is 1 hour). Keep the temperature for 10 minutes respectively, and then lower to room temperature to obtain a molybdenum disulfide/graphene layered assembly.

The double-layer molybdenum disulfide/graphene layered assembly was prepared into a super-large phototransistor and its photoelectric performance was tested. It obtained excellent photoelectric conversion and photocurrent response performance. The photocurrent density can still reach 94μW/cm ² at the light intensity 3.0μA/cm ² , the photocurrent response can be completed within 2.3s at the moment of light on-off, and the photocurrent has no obvious attenuation within 8 cycles.

The molybdenum disulfide/graphene layered assembly prepared by the present invention has the characteristics of large area and high quality, and has good application in the field of optoelectronic devices such as secondary batteries, field effect transistors, sensors, organic electroluminescence, and electric storage. Application prospect.

Description of drawings

The optical photo of the double-layer molybdenum disulfide/graphene layered assembly obtained in (a) implementation example 1 among Fig. 1;

The optical photo of the bilayer MoS ₂ /graphene layered assembly obtained in (b) implementation example 1 in Fig. 1;

The optical photo of the bilayer MoS ₂ /graphene layered assembly obtained in (c) implementation example 1 in Fig. 1;

TEM image of the bilayer molybdenum disulfide/graphene layered assembly in (a) Example 2 in FIG. 2 .

(b) TEM image of the bilayer molybdenum disulfide/graphene layered assembly in Example 2 in FIG. 2 .

(a) High magnification TEM image of the three-layer molybdenum disulfide/graphene layered assembly obtained in Example 3 in (a) of FIG. 3 .

In Fig. 3 (b) the high-magnification TEM image of the three-layer molybdenum disulfide/graphene layered assembly obtained in Example 3.

detailed description

The specific examples of the present invention given below are further descriptions of the present invention, rather than limiting the scope of the present invention.

Example 1:

The graphene used in this example is prepared and transferred by the method of the present invention.

(1) Place the SiO ₂ /Si substrate transferred with graphene film directly above the boat-shaped porcelain boat with 5 mg of molybdenum trioxide powder, and place the boat-shaped porcelain boat with 500 mg of sulfur powder in the first tube furnace. Heating zone, and then put the porcelain boat with molybdenum trioxide in the second heating zone of the tube furnace, and pass argon gas to exhaust the air in the quartz tube before starting to heat up.

(2) Under the protection of 50 sccm argon gas, the pressure is increased to 133.29 Pa, within one hour, the temperature of the first heating zone is raised to 160° C., and the temperature of the second heating zone is raised to 650° C. at the same time. Keep the temperature for 10 minutes, and then lower it to room temperature to obtain a double-layer molybdenum disulfide/graphene layered assembly.

The optical photographs of the samples in this embodiment are shown in (a), (b), and (c) in Figure 1 . Figure (b) is an enlarged image of the framed area in Figure (a). Further comparison shows the uniformity of large-area graphene and the uniformity of large-area molybdenum disulfide on graphene. Figure (c) is an enlarged image of the square area in Figure (b), from which it can be seen that a large area of molybdenum disulfide is grown on the graphene film. The color consistency of molybdenum disulfide can also indicate that the crystal quality of molybdenum disulfide is very good.

The double-layer molybdenum disulfide/graphene layered assembly was prepared into a super-large phototransistor and its photoelectric performance was tested. It obtained excellent photoelectric conversion and photocurrent response performance. The photocurrent density can still reach 94μW/cm ² at the light intensity 3.0μA/cm ² , the photocurrent response can be completed within 2.3s at the moment of light on-off, and the photocurrent has no obvious attenuation within 8 cycles.

Example 2:

The graphene used in this example is purchased from Nanjing Xianfeng Nano Material Technology Co., Ltd., the number is: XF040, and the parameters are: single layer, size 1cm*1cm.

(1) Place the SiO ₂ /Si substrate transferred with graphene film directly above the boat-shaped porcelain boat with 10 mg of molybdenum trioxide powder, and place the boat-shaped porcelain boat with 500 mg of sulfur powder in the first tube furnace. Heating zone, and then put the porcelain boat with molybdenum trioxide in the second heating zone of the tube furnace, and pass argon gas to exhaust the air in the quartz tube before starting to heat up.

(2) Under the protection of 50 sccm argon gas, the pressure is increased to 133.29 Pa, within one hour, the temperature of the first heating zone is raised to 160° C., and the temperature of the second heating zone is raised to 650° C. at the same time. Keep the temperature for 10 minutes respectively, and then lower to room temperature to obtain a double-layer molybdenum disulfide/graphene layered assembly.

The results obtained in this embodiment are shown in Figure 2, (a) in Figure 2, (b) simply illustrate the growth process of molybdenum disulfide on the graphene template, molybdenum disulfide is deposited on the surface of graphene to form tens of Nano-scale molybdenum disulfide particles, the reaction is further carried out, and the micron-scale molybdenum disulfide continues to be connected into a large-area molybdenum disulfide on graphene as shown in figure (b).

Example 3:

The graphene used in this example is according to literature: Li X, Cai W, An J, et al.Large-areasynthesis of high-quality and uniform graphene films on copper foils.[J].Science,2009,324(5932 ):1312. Prepared.

(1) Place the SiO ₂ /Si substrate transferred with graphene film directly above the boat-shaped porcelain boat with 15 mg of molybdenum trioxide powder, and place the boat-shaped porcelain boat with 500 mg of sulfur powder in the first tube furnace. Heating zone, and then put the porcelain boat with molybdenum trioxide in the second heating zone of the tube furnace, and pass argon gas to exhaust the air in the quartz tube before starting to heat up.

(2) Then, under the protection of 50 sccm argon gas, the pressure was raised to 133.29 Pa. Over a period of one hour, the first heating zone was raised to 160°C and the second heating zone was simultaneously raised to 650°C. Keep the temperature for 10 minutes respectively, and then lower to room temperature to obtain a three-layer molybdenum disulfide/graphene layered assembly.

The transmission electron micrograph of the sample in this embodiment is shown in FIG. 3 . It can be clearly seen from Figure 3 that the obtained molybdenum disulfide has good crystallinity.

Claims (7)

1. the preparation method of a kind of molybdenum disulfide/graphene stratiform assembly, it is characterised in that including procedure below：

(1) single quartz ampoule is used, coordinates the tube furnace of double furnace；The SiO for having graphene film will be shifted₂/ Si substrates, put In being placed with above the container of molybdenum trioxide powder, the container for being placed with sulphur powder is placed in first heating furnace center of tube furnace；Again The container for being placed with molybdenum trioxide is put in second heating furnace center of tube furnace；It is passed through argon gas；

2) under an argon atmosphere, tube furnace internal pressure is emphasized to 133.29Pa, the first heating zone is warming up to the volatilization temperature of sulphur powder Degree, the second heating zone is warming up to the volatilization temperature of molybdenum trioxide；Molybdenum disulfide is deposited on substrate, be then down to room temperature, must To molybdenum disulfide/graphene stratiform assembly.

2. the method as described in claim 1, it is characterized in that SiO₂/ Si substrates are failed to grow up in 1cm, wide to be not more than 1cm, thickness 0.5mm。

3. the method as described in claim 1, it is characterized in that the container for being placed with molybdenum trioxide powder is ship type porcelain boat.

4. method as claimed in claim 3, it is characterized in that ship type porcelain boat long 6cm, wide 3cm, deep 1cm.

5. the method as described in claim 1, it is characterized in that molybdenum trioxide and the mass ratio of sulphur powder are 1~3:100.

6. the method as described in claim 1, it is characterized in that 160 DEG C of the volatilization temperature of sulphur powder.

7. the method as described in claim 1, it is characterized in that 650 DEG C of the volatilization temperature of molybdenum trioxide.