CN113418552B - A two-dimensional transition metal sulfide material flexible sensor and preparation method thereof - Google Patents

Abstract

A two-dimensional transition metal sulfide material flexible sensor, comprising electrodes, wires and a semiconductor material; wherein, the electrodes and the semiconductor material are connected through the wires, and the semiconductor material comprises a substrate, a two-dimensional transition metal sulfide, and a conductive strip connected to the substrate and the two-dimensional transition metal sulfide. The device of the present invention has a simple structure, the two-dimensional material and the paper-based flexible substrate are easy to combine, the conductive electrode is convenient to build, and the overall preparation cost is low; at the same time, the overall device preparation process of the present invention has no special requirements for the two-dimensional material, does not introduce other difficult-to-remove substances, and is flexible. The sensor device preparation method has universality and stable performance, and can be suitable for large-scale production.

Description

A two-dimensional transition metal sulfide material flexible sensor and preparation method thereof

technical field

The invention belongs to the technical field of semiconductor flexible device preparation, in particular to a preparation method and application of a two-dimensional transition metal sulfide material flexible sensor.

Background technique

Transition metal dichalcogenides (TMDs) refer to a layered structure material with chemical formula MX ₂ formed by transition metal group elements M (such as molybdenum, tungsten, titanium) and chalcogen elements X (such as sulfur, selenium, tellurium). , the layers are combined with weak van der Waals force, which is easy to peel off. When the transition metal sulfide is peeled off at least one layer or even a single layer, it will be transformed from an indirect bandgap semiconductor to a direct bandgap semiconductor, and its layered structure will be transformed from three-dimensional to two-dimensional, so that two-dimensional transition metal sulfides can have excellent electrical properties. , optical and bending properties, it has great potential in the application and preparation of new flexible electronic devices.

Currently, two-dimensional TMDs materials often require complex material transfer techniques and High-cost evaporation electrodes are used to prepare flexible devices, so that flexible sensor elements with simple device structure, low cost and reliable performance cannot be obtained. It is necessary to design a reasonable device structure and find a suitable flexible device substrate and two-dimensional TMDs material preparation. The preparation method can obtain a stable and reliable two-dimensional TMDs material-based flexible sensor device.

Therefore, it is an urgent problem for those skilled in the art to provide a flexible sensor with a simple structure and low cost and a preparation method thereof.

SUMMARY OF THE INVENTION

In view of this, the present invention provides a two-dimensional transition metal sulfide material flexible sensor and a preparation method thereof. Through a reasonable and feasible device structure design, the present invention successfully solves the difficulty in preparing two-dimensional transition metal sulfides with simple structure and low cost. of flexible sensor devices.

In order to achieve the above object, the present invention adopts the following technical solutions:

A two-dimensional transition metal sulfide material flexible sensor, comprising electrodes, wires and a semiconductor material; wherein, the electrodes and the semiconductor material are connected through the wires, and the semiconductor material comprises a substrate, a two-dimensional transition metal sulfide, and a conductive strip connected to the substrate and the two-dimensional transition metal sulfide.

The device of the invention has a simple structure, the two-dimensional material is easily combined with the paper-based flexible substrate, the conductive electrode is conveniently constructed, and the overall preparation cost is low.

Preferably, the substrate is a filter membrane with a pore size below 0.22um.

Preferably, the substrate is any one of polyvinylidene fluoride, hydrophilic polycarbonate film and mixed cellulose.

The filter membrane substrate can tightly adsorb two-dimensional materials to form a membrane through a simple suction filtration method, which cannot be achieved by other flexible substrates; and has good mechanical bending strength, and the preparation and combination method is simple.

Preferably, the preparation method of the semiconductor material is:

(1) Mix the transition metal sulfide powder with the n-butyllithium solution, heat and stir at 40-60°C for 24-48h, filter, add deionized water to the precipitate and ultrasonically peel for 1-1.5h, to obtain a suspension liquid;

(2) centrifuging the suspension to remove the precipitation to obtain a two-dimensional transition metal sulfide suspension;

(3) suction filtration of the two-dimensional transition metal sulfide suspension to the substrate, then after washing with water, alcohol washing and drying, a two-dimensional transition metal sulfide composite film is obtained;

(4) connecting the conductive tape with the surface of the two-dimensional transition metal sulfide and the surface of the filter membrane to obtain a semiconductor material.

Compared with methods for preparing two-dimensional transition metal sulfides such as mechanical peeling method and vapor deposition method, the method of the invention has the advantages of simple preparation, high yield, no difficult removal of impurities, and easy subsequent suction filtration and adsorption treatment; The conductive tape can be attached to the material and the substrate.

Preferably, in step (1), the transition metal sulfide powder is any one of molybdenum sulfide or tungsten sulfide, and the concentration of the n-butyllithium solution is 1.8-2.2 mol/L.

The present invention adopts raw materials for easy preparation, wide purchasing sources and low relative cost.

Preferably, the mass volume ratio of the transition metal sulfide powder and the n-butyllithium solution in step (1) is 0.3-0.8 g:10-20 mL.

In the proportion of the invention, the added amount of transition metal sulfide powder is large, and the yield of preparing two-dimensional materials is high.

Preferably, the mass-volume ratio of the transition metal sulfide powder to the deionized water in step (1) is 0.3-0.8 g:80-100 mL.

Preferably, the conditions for centrifugation in step (2) are: centrifugation at 1500-3000 r/min for 10-15 min.

Preferably, the drying conditions in step (3) are: vacuum drying at 45-55° C. for 1.52 h.

The above-mentioned preparation method of a two-dimensional transition metal sulfide material flexible sensor includes the following specific steps: connecting one end of the wire with the electrode, and attaching the other end to the end of the conductive tape to form a conductive path from the electrode to the semiconductor material, that is, to obtain A two-dimensional transition metal sulfide material flexible sensor.

In the present invention, the electrode construction is very simple and feasible, there is no packaging difficulty, and a high success rate of device preparation can be ensured.

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

1) The device structure of the present invention is simple, the two-dimensional material is tightly combined with the paper-based flexible substrate through suction filtration, so the adhesion is high, the conductive electrode is convenient to build, and the overall preparation cost is low;

2) The overall device preparation process of the present invention has no special requirements for two-dimensional materials, and no other difficult-to-remove substances are introduced. The flexible sensor device preparation method has universality and stable performance, and can be suitable for large-scale production.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only It is an embodiment of the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to the provided drawings without creative work.

1 is a flow chart of the preparation of a two-dimensional transition metal sulfide material flexible sensor according to an embodiment of the present invention;

2 is a structural diagram of a two-dimensional tungsten disulfide-based flexible device according to Embodiment 1 of the present invention;

Fig. 3 is the response curve diagram that the application example of the present invention obtains;

FIG. 4 is a flow chart of the preparation of the flexible sensor of the comparative example of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Example 1

As shown in Figure 1, a preparation method of a two-dimensional transition metal sulfide material flexible sensor includes the following specific steps:

(1) Take 0.6g of layered tungsten disulfide powder and put it in a 30mL conical flask, and move it into a glove box protected by an inert gas; add 15mL of n-butyllithium solution (concentration: 2M, solvent: n-hexane) into the conical flask Inside, heat and stir at 60°C for 24 hours after sealing; filter the n-butyllithium-treated tungsten disulfide powder with n-hexane to remove the surface n-butyllithium, put it in a three-necked flask and add 100 mL of deionized water for ultrasonic peeling for 1 hour, collect the ultrasonic the suspension;

(2) centrifuge the suspension at 1500r/min for 15min, remove the unstripped thick sheet, and obtain a two-dimensional tungsten disulfide suspension;

(3) Suction filtration of 30 mL of the suspension onto a polyvinylidene fluoride membrane (Merck Millipore, 0.22um pore size, GVHP04700), washed with water and alcohol for three times to remove impurities, and then placed at 45°C and dried in vacuum After 2 h, a two-dimensional tungsten disulfide composite film that closely adhered to the filter membrane and was uniformly dispersed was obtained.

(4) According to the shape requirements of the device, trim the two-dimensional tungsten disulfide composite film, stick a suitable double-sided conductive tape (single-sided tape) on the surface of the two-dimensional transition metal sulfide and the surface of the filter membrane, and then use DuPont wire to stick it on the surface of the filter membrane. The end of the conductive tape forms a conductive path from the electrode to the semiconductor material, and finally a two-dimensional tungsten disulfide-based flexible sensor device with a simple device structure and tight bonding is prepared (as shown in Figure 2).

Example 2

As shown in Figure 1, a preparation method of a two-dimensional transition metal sulfide material flexible sensor includes the following specific steps:

(1) Take 0.3g of layered tungsten disulfide powder and put it in a 30mL conical flask, and move it into a glove box protected by an inert gas; add 10mL of n-butyllithium solution (concentration: 1.8M, solvent: n-hexane) into the conical In the bottle, heat and stir at 60°C for 24 hours after sealing; filter the n-butyllithium-treated tungsten disulfide powder with n-hexane, remove the surface n-butyllithium, put it in a three-necked flask, add 80 mL of deionized water, and ultrasonically peel for 1 hour, and collect the ultrasonic waves. after the suspension;

(2) centrifuge the suspension at 1500r/min for 10min, remove the unstripped thick sheet, and obtain a two-dimensional tungsten disulfide suspension;

(3) Suction filtration of 30 mL of the suspension onto a polyvinylidene fluoride membrane (Merck Millipore, 0.22um pore size, GVHP04700), washed with water and alcohol for three times to remove impurities, and then placed at 45°C and dried in vacuum After 1.5 h, a two-dimensional tungsten disulfide composite film that closely adhered to the filter membrane and was uniformly dispersed was obtained.

(4) According to the shape requirements of the device, trim the two-dimensional tungsten disulfide composite film, stick a suitable double-sided conductive tape (single-sided tape) on the surface of the two-dimensional transition metal sulfide and the surface of the filter membrane, and then use DuPont wire to stick it on the surface of the filter membrane. The end of the conductive tape forms a conductive path from the electrode to the semiconductor material, and finally a two-dimensional tungsten disulfide-based flexible sensor device with a simple device structure and tight bonding is prepared (as shown in Figure 2).

Example 3

As shown in Figure 1, a preparation method of a two-dimensional transition metal sulfide material flexible sensor includes the following specific steps:

(1) Take 0.8g of layered tungsten disulfide powder and put it in a 30mL conical flask, and move it into a glove box protected by an inert gas; add 20mL of n-butyllithium solution (concentration: 2.2M, solvent: n-hexane) into the conical In the bottle, heat and stir at 40°C for 48h after sealing; filter the n-butyllithium-treated tungsten disulfide powder with n-hexane, remove the surface n-butyllithium, put it in a three-necked flask and add 100mL deionized water to ultrasonically peel for 1.5h, and collect Suspension after ultrasound;

(2) centrifuge the suspension at 3000r/min for 15min, remove the unstripped thick sheet, and obtain a two-dimensional tungsten disulfide suspension;

(3) Suction filtration of 30 mL of the suspension onto a polyvinylidene fluoride filter membrane (Merck Millipore, 0.22um pore size, GVHP04700), washed with water and alcohol for three times to remove impurities, then placed at 55°C and dried in vacuum After 2 h, a two-dimensional tungsten disulfide composite film that closely adhered to the filter membrane and was uniformly dispersed was obtained.

(4) According to the shape requirements of the device, trim the two-dimensional tungsten disulfide composite film, stick a suitable double-sided conductive tape (single-sided tape) on the surface of the two-dimensional transition metal sulfide and the surface of the filter membrane, and then use DuPont wire to stick it on the surface of the filter membrane. The end of the conductive tape forms a conductive path from the electrode to the semiconductor material, and finally a two-dimensional tungsten disulfide-based flexible sensor device with a simple device structure and tight bonding is prepared (as shown in Figure 2).

Application example

(1) When the device prepared in Example 1 was placed between the upper lip and the nose, the response curve of the two-dimensional tungsten disulfide flexible sensor device to relatively weak and deep breathing signals was obtained, namely (a) in Figure 3; The change of the current signal intensity of the sensor, the product of the present invention can detect and distinguish weak and deep breathing. The main principle is that the difference in exhalation intensity leads to the difference in airflow intensity and water and oxygen flow rate, which will cause the sensor sensitive material tungsten disulfide to carry current. Changes in subconcentrations are ultimately reflected in changes in current signal strength.

(2) The device prepared in Example 1 was continuously pulsed NH ₃ gas with a concentration of 500 ppm in the actual environment, and the response curve was obtained, that is, (b) in Figure 3; NH ₃ molecules and WS ₂ will be adsorbed for electronic interaction. , eliciting a change in the baseline current of WS ₂ , it can be seen that the response intensity of WS ₂ to 500 ppm of pulsed NH ₃ gas at room temperature is about 6%.

(3) Simultaneously bend the response of the device prepared in Example 1 and the response to 200 ppm NH ₃ gas in a closed cavity to obtain a response curve diagram, namely (c) in Figure 3, the inset shows an enlarged diagram of the bending response curve (bending The radius is 10mm); through the bending experiment of the sensor while passing NH ₃ gas, it can be seen that the sensor shows a response intensity of 6% to NH ₃ gas under the overall response, and the enlarged signal graph can be seen , the device also exhibits the phenomenon of regular current changes to the bending. This indicates that the flexible sensor can simultaneously acquire and present multiple signals of gas response and bending response.

(4) Detect the response curve of the sensor to 500 ppm NH ₃ before and after bending the device prepared in Example 1 for 8000 times, and obtain the response curve diagram, namely (d) in FIG. 3 . Through repeated bending experiments, it can be seen that the flexible sensor can still maintain a good current response. Therefore, the electrical performance of the device is stable.

Comparative ratio

A more advanced method for preparing two-dimensional transition metal sulfide-based flexible sensors currently reported in the literature is shown in Figure 4, which was reported by Zhao et al. (References: Zhao Y, Song JG, Ryu GH, et al. Low-temperature synthesis of 2D MoS ₂ on a plastic substrate for a flexible gas sensor[J]. Nanoscale, 2018, 10(19): 9338-9345) A vapor deposition method (CVD) for two-dimensional growth at relatively low temperature (200 °C) Molybdenum sulfide material is deposited on the traditional flexible substrate PI, and then titanium (Ti, 2nm)/gold (Au, 40nm) electrodes are evaporated on the PI substrate with two-dimensional molybdenum sulfide material through a mask by thermal evaporation method, so as to A two-dimensional molybdenum sulfide-based flexible gas sensor was prepared; this method requires high experimental conditions in terms of material preparation methods, and needs to be carried out in a high-temperature tube furnace, and the substrate PI material needs to undergo strict cleaning steps before it can be used for material growth. The material growth experiment is random, and the yield cannot be guaranteed; in addition, the electrode needs to be adhered to the material by thermal evaporation of the metal electrode through a complex and expensive mask, the preparation is complicated and the cost is high, and it cannot be prepared on a large scale. Two-dimensional metal sulfide-based flexible sensor devices.

The various embodiments are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the various embodiments may be referred to each other.

The above description of the disclosed embodiments enables any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (9)

1. a two-dimensional transition metal sulfide material flexible sensor, is characterized in that, comprises electrode, wire and semiconductor material; Wherein, described electrode and described semiconductor material are connected by described wire, and described semiconductor material comprises filter membrane substrate , a two-dimensional transition metal sulfide, and a conductive band connected to the filter membrane substrate and the two-dimensional transition metal sulfide; The preparation method of the semiconductor material is: (1) Mix the transition metal sulfide powder with the n-butyllithium solution, heat and stir at 40-60°C for 24-48h, filter, add deionized water to the precipitate and carry out ultrasonic peeling for 1-1.5h, that is, the suspension is obtained. turbid liquid; (2) centrifuging the suspension to remove precipitation to obtain a two-dimensional transition metal sulfide suspension; (3) suction-filtering the two-dimensional transition metal sulfide suspension to a filter membrane substrate, and then washing with water, alcohol, and drying to obtain a two-dimensional transition metal sulfide composite film; (4) Connecting the conductive tape with the surface of the two-dimensional transition metal sulfide and the surface of the filter membrane substrate to obtain a semiconductor material. 2 . The two-dimensional transition metal sulfide material flexible sensor according to claim 1 , wherein the filter membrane substrate is a filter membrane with a pore size of less than 0.22 μm. 3 . 3. A kind of two-dimensional transition metal sulfide material flexible sensor according to claim 1, is characterized in that, described filter membrane base is polyvinylidene fluoride filter membrane, hydrophilic polycarbonate microporous filter membrane and mixed Any of the cellulose filters. 4 . The two-dimensional transition metal sulfide material flexible sensor according to claim 1 , wherein the transition metal sulfide powder in step (1) is molybdenum sulfide or tungsten sulfide, and the n-butyllithium The concentration of the solution is 1.8-2.2 mol/L. 5 . The two-dimensional transition metal sulfide material flexible sensor according to claim 1 , wherein the mass-volume ratio of the transition metal sulfide powder and the n-butyllithium solution in step (1) is 5 . 0.3-0.8g: 10-20mL. 6 . The two-dimensional transition metal sulfide material flexible sensor according to claim 1 , wherein the mass-volume ratio of the transition metal sulfide powder to the deionized water in step (1) is 0.3- 0.8g: 80-100mL. 7 . The two-dimensional transition metal sulfide material flexible sensor according to claim 1 , wherein the centrifugation conditions in step (2) are: centrifugation at 1500-3000 r/min for 10-15 min. 8 . 8 . The two-dimensional transition metal sulfide material flexible sensor according to claim 1 , wherein the drying conditions in step (3) are: vacuum drying at 45-55° C. for 1.5-2 hours. 9 . 9. The preparation method of a two-dimensional transition metal sulfide material flexible sensor according to any one of claims 1-8, wherein the method comprises the following specific steps: connecting one end of the wire with the electrode, and attaching the other end to the conductive Tape the end to form a conductive path from the electrode to the semiconductor material, thus obtaining a two-dimensional transition metal sulfide material flexible sensor.

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