CN109411331B - Two-dimensional superlattice indium selenide, preparation method thereof and application thereof in preparation of photoelectric detector - Google Patents

Abstract

The invention discloses a two-dimensional superlattice indium selenide, a preparation method thereof, and an application in the preparation of a photoelectric detector, belonging to the field of high-performance photoelectric detectors; the preparation method of the two-dimensional superlattice indium selenide is: SiO ₂ /Si substrate pretreatment; paste InSe material with scotch tape and transfer it to SiO ₂ /Si substrate, soak in acetone; high temperature treatment under vacuum conditions, two-dimensional superlattice InSe nanostructures can be prepared on the surface of SiO ₂ /Si substrate piece. The two-dimensional superlattice InSe prepared by the method of the invention has high electrical transport performance, high light response, good stability and fast light response speed, and has a good application prospect in the field of high-performance photodetectors.

Description

Two-dimensional superlattice indium selenide and its preparation method and use in the preparation of photodetectors application

technical field

The invention belongs to the field of high-performance photoelectric detectors, and in particular relates to two-dimensional superlattice indium selenide, a preparation method thereof, and applications in the preparation of photoelectric detectors.

Background technique

A photodetector is a device that converts optical signals into electrical signals. It has great application prospects in the fields of optical communication, optical imaging, environmental monitoring, missile monitoring and remote control. It is a hot research field in the scientific community and attracts scientists. wide attention and rapid development. Semiconductor materials with good light-absorbing ability and electrical properties are the basis for designing and fabricating high-performance photodetectors. Photodetectors based on traditional semiconductor materials (silicon, gallium nitride, and indium gallium arsenide) exhibit small photodetection performance, with photoresponse values less than 1 A/W.

Nanomaterials have special electrical and optical properties different from three-dimensional materials, and have great application prospects in the field of high-performance photodetectors. So far, scientists have explored various nanomaterials such as carbon nanotubes and nanowires. However, the poor stability of devices and poor repeatability of materials are the biggest problems that plague the application of 1D nanomaterials. Two-dimensional semiconductor materials can overcome the weaknesses of one-dimensional materials and are compatible with current thin-film integration technologies. However, the electrical transport properties of two-dimensional semiconductor materials are much smaller than that of three-dimensional semiconductor materials. The exploration of two-dimensional semiconductor materials with high electrical transport properties is of great significance for the development of high-performance photodetectors.

SUMMARY OF THE INVENTION

The invention aims to solve the technical problems of poor electrical transport performance of existing two-dimensional semiconductor materials and low photodetection performance of photodetectors, and provides a preparation method of two-dimensional superlattice indium selenide and the method for preparing the photodetector. applications in .

The invention uses indium selenide (InSe) nanosheets as raw materials, adopts a solid phase annealing method to prepare a two-dimensional superlattice InSe, and constructs a photodetector.

First, the present invention provides a preparation method of two-dimensional superlattice indium selenide, and the technical scheme is as follows:

Step 1, pretreating the SiO ₂ /Si substrate;

Step 2: Repeatedly stick the bulk InSe material with scotch tape, and then stick the scotch tape on the SiO ₂ /Si substrate processed in step 1. After tearing off the scotch tape, soak the SiO ₂ /Si substrate in acetone, take out The SiO ₂ /Si substrate can obtain randomly distributed two-dimensional InSe nanosheets on its surface;

Step 3. Put the SiO ₂ /Si substrate into the tube furnace, evacuate the tube furnace, and pass in the mixed gas of Ar/H ₂ , heat up to 350 ° C, keep the temperature, and then cool down to room temperature, take out the SiO ₂ / Si substrate, that is, two-dimensional superlattice InSe nanosheets can be prepared on the surface of SiO ₂ /Si substrate.

In step 1, the thickness of the SiO ₂ /Si substrate is 300 nm. The SiO ₂ /Si substrate pretreatment method is specifically as follows: the SiO ₂ /Si substrate is immersed in isopropanol, acetone, ethanol and ultrapure water in sequence for ultrasonic treatment, dried with nitrogen, and ready for use. The essence of the ultrasonic treatment is to perform ultrasonic cleaning, and the ultrasonic frequency can be above 10KHz.

In step 2, the repeated sticking of the bulk InSe material refers to sticking the scotch tape on the surface of the bulk InSe material, then removing the scotch tape, repeating the above operation 4-9 times, and using the same position of the scotch tape for each sticking operation (roughly overlapping).

In step 2, the Scotch single-sided scotch tape is preferred for the scotch tape.

In the second step, the transparent tape is pasted on the SiO ₂ /Si substrate processed in the first step, and the pasting time is 5-12 hours.

In the second step, the SiO ₂ /Si substrate is soaked in acetone, and the soaking time is 2-4 hours.

In step 3, the vacuum is performed, and the pressure is 50-100 Torr.

In step 3, in the mixed gas of Ar/H ₂ , the volume ratio of Ar/H ₂ is (9-4):1; the flow rate of the mixed gas of Ar/H ₂ is 100-150 sccm.

In step 3, in the temperature increase, the temperature increase rate is 20-40°C/min.

In step 3, the heat preservation time is 0.5-1.5 hours.

In step 3, the cooling rate is 100-200°C/min.

In addition, the present invention also provides the _two -dimensional superlattice InSe prepared by the above method and its application in the preparation of photodetectors. , use silver glue to fix the metal mask on one side of the InSe nanosheet to cover the center of the two-dimensional superlattice InSe nanosheet, leaving a width of at least 3 μm on each side of the two-dimensional superlattice InSe nanosheet, and then place it in a vacuum coating In the machine, a metal chromium electrode and a metal gold electrode are sequentially evaporated on one side of the InSe nanosheet under vacuum conditions to obtain a two-dimensional superlattice indium selenide photodetector for ultraviolet-visible light detection.

The SiO ₂ /Si substrate with two-dimensional superlattice InSe nanosheets on the surface has a lateral size of 20-40 μm and a thickness of 20-40 nm on the surface of the InSe nanosheets.

In the vacuum conditions, the degree of vacuum is 1×10 ^-4 -5×10 ^-4 Pa.

The thickness of the vapor-deposited metal chromium electrode is 5-10 nm.

The thickness of the vapor-deposited metal gold electrode is 30-50 nm.

beneficial effect

The two-dimensional superlattice InSe prepared by the method of the invention has high electrical transport performance, high light response, good stability and fast light response speed, and has good application prospects in the field of high-performance photodetectors.

The two-dimensional superlattice InSe prepared by the method of the present invention is used to prepare a photodetector, and the obtained photodetector has a significant increase in current under the irradiation of visible light, indicating that the two-dimensional superlattice InSe prepared by the present invention has good photoelectric detection performance. The photoresponse value is as high as the gage factor as high as 1.95×10 ⁵ A/W, which is much higher than that of traditional semiconductors (silicon, gallium nitride and indium gallium arsenide < 1A/W) and two-dimensional semiconductor materials (InSe: 10 ³ A/W, MoS ₂ :880A/W).

The two-dimensional superlattice InSe prepared by the method of the invention is used to prepare a photodetector, and the obtained photodetector has good stability and fast corresponding speed (20ms). The device field has great application prospects.

Description of drawings

1 is a selected electron diffraction image of a) two-dimensional InSe and b) two-dimensional superlattice InSe;

Figure 2 is a) a three-dimensional schematic diagram, b) an optical image and c) an atomic force image of a two-dimensional superlattice InSe photodetector;

Figure 3 is the electrical transport properties of the prepared two-dimensional superlattice InSe: a) transfer curve and b) output curve;

Fig. 4 is the current curve of the two-dimensional superlattice InSe photodetector under excitation light of 700 nm;

Figure 5 is a) stability and b) response speed curves of a two-dimensional superlattice InSe photodetector.

Detailed ways

Example 1 Preparation of two-dimensional superlattice InSe

Step 1. The SiO ₂ /Si substrate with a thickness of 300 nm is ultrasonically treated with isopropanol, acetone, ethanol and ultrapure water at 10KHz in turn, the ultrasonic treatment time is 10min, dried with nitrogen, and set aside for use;

Step 2: Repeatedly paste the bulk InSe material 6 times at the same position with the transparent tape, and then paste the transparent tape on the SiO ₂ side of the 300nm SiO ₂ /Si substrate processed in the first step for 8 hours. After removing the transparent tape , soak the SiO ₂ /Si substrate in acetone for 3 hours, and then take out the SiO ₂ /Si substrate to obtain randomly distributed two-dimensional InSe nanosheets on its surface;

Step 3. Put the SiO ₂ /Si substrate into the tube furnace, evacuate the tube furnace to 80 Torr, and feed the mixed _gas of _100sccmAr / _H The furnace temperature was raised to 350°C, maintained for 1 hour, and then lowered to room temperature for 2 minutes, and the SiO ₂ /Si substrate was taken out to obtain the two-dimensional superlattice InSe.

Example 2 Preparation of two-dimensional superlattice InSe photodetector

The two-dimensional superlattice InSe nanosheets with a lateral dimension of 50 μm and a thickness of 31 nm on the surface of the 300 nm SiO ₂ /Si substrate prepared in Example 1 were selected, and the two-dimensional superlattice InSe nanosheets were covered with a silver glue-fixed metal mask. In the center position, two-dimensional superlattice InSe nanosheets with a width of 3 μm are left on each side, and then placed in a vacuum coating machine, under the condition of vacuum degree of 3×10 ^-4 Pa, on the two-dimensional superlattice InSe nanosheets one The two-dimensional superlattice InSe photodetector can be obtained by evaporating 5nm metal chromium and 40nm metal gold electrodes in turn.

Detection of excitation light at 700 nm using the two-dimensional superlattice InSe photodetector of this embodiment:

In this embodiment, two-dimensional superlattice InSe nanosheets are obtained by heat treatment. FIG. 1 is a selected electron diffraction image of intrinsic InSe and superlattice InSe. By comparison, it can be known that two-dimensional superlattice InSe can be obtained by heat treatment. The two-dimensional superlattice InSe with a size of 20-40 μm and a thickness of 20-40 nm was selected as the channel material of the photodetector. Figure 2c is the atomic force image of the two-dimensional superlattice InSe photodetector, and the thickness of the selected two-dimensional superlattice InSe nanosheet is 31 nm as shown in Figure 2c. Figure 3 is the electrical transport curve of the prepared two-dimensional superlattice InSe. The calculated electron mobility of the superlattice InSe is as high as 299cm ² V ^-1 s ^-1 . It can be seen from Figure 3 that the mechanical sensor has high electrical Conductive properties, laying the foundation for high-performance photodetectors. Figure 4 is the current curve of the two-dimensional superlattice InSe photodetector under the excitation of 700 nm excitation light with an excitation power of 0.29 mW/cm ² . It can be seen from Figure 4 that the current increases significantly under the action of 700 nm excitation light, indicating that the two-dimensional InSe It has good photodetection performance, and the photoresponse of the photodetector is calculated to be as high as 1.95×10 ⁵ A/W when a voltage of 5V is applied. Figure 5 shows the stability and response speed curves of the photodetector under the test conditions of 0.1V voltage and 700nm excitation light of 0.29mW/ ^cm2 . It can be seen that the two-dimensional superlattice InSe photodetector has good stability The high photoresponse and fast photoresponse speed (20ms) further indicate that the two-dimensional superlattice InSe has good photodetection performance.

Claims (9)

1. a preparation method of two-dimensional superlattice indium selenide, is characterized in that: comprise the following steps: Step 1, pretreating the SiO ₂ /Si substrate; Step 2: Repeatedly stick the bulk InSe material with scotch tape, and then stick the scotch tape on the SiO ₂ /Si substrate processed in step 1. After tearing off the scotch tape, soak the SiO ₂ /Si substrate in acetone, take out The SiO ₂ /Si substrate obtains randomly distributed two-dimensional InSe nanosheets on its surface; Step 3, put the SiO ₂ /Si substrate into the tube furnace, evacuate the tube furnace, and pass into the mixed gas of Ar/H ₂ , the volume ratio of Ar/H ₂ is (9-4): 1, The temperature was raised to 350 °C, maintained at a temperature of 20-40 °C/min, and the SiO ₂ /Si substrate was taken out to obtain two-dimensional superlattice InSe nanosheets on the surface of the SiO ₂ /Si substrate; the heating rate was 20-40 ° C/min; the holding time was It is 0.5-1.5 hours; the cooling rate is 100-200 ℃/min. 2 . The preparation method of two-dimensional superlattice indium selenide according to claim 1 , wherein in step 1, the thickness of the SiO ₂ /Si substrate is 300 nm; the SiO ₂ /Si substrate is pretreated. 3 . The specific method is as follows: the SiO ₂ /Si substrate is sequentially immersed in isopropanol, acetone, ethanol and ultrapure water for ultrasonic treatment, dried with nitrogen, and set aside for use. 3. The preparation method of two-dimensional superlattice indium selenide according to claim 1, characterized in that: in step 2, the repeated sticking of the bulk InSe material refers to sticking a scotch tape on the surface of the bulk InSe material, Then remove the scotch tape and repeat the operation 4-9 times. 4. The preparation method of two-dimensional superlattice indium selenide according to claim 1, characterized in that: described in step 2, the transparent tape is pasted on the SiO ₂ /Si substrate processed in step one, and the pasting time 5~12 hours. 5 . The method for preparing two-dimensional superlattice indium selenide according to claim 1 , wherein in step 2, the SiO ₂ /Si substrate is soaked in acetone for a soaking time of 2 to 4 hours. 6 . 6. The preparation method of two-dimensional superlattice indium selenide according to claim 1, characterized in that: in step ₃ , the vacuum is evacuated, and the pressure is 50-100 Torr; The flow rate of the mixed gas is 100-150 sccm. 7. A two-dimensional superlattice indium selenide prepared by the method for preparing two-dimensional superlattice indium selenide according to any one of claims 1-6. 8. A method for preparing a photodetector using the two-dimensional superlattice indium selenide as claimed in claim 7, characterized in that: taking a SiO ₂ /Si substrate with a two-dimensional superlattice InSe nanosheet on the surface, On one side of the InSe nanosheets, a metal mask was fixed with silver glue to cover the center of the two-dimensional superlattice InSe nanosheets, leaving a width of at least 3 μm on each side of the two-dimensional superlattice InSe nanosheets, and then placed in vacuum coating In the machine, a metal chromium electrode and a metal gold electrode are sequentially evaporated on one side of the InSe nanosheet under vacuum conditions to obtain a two-dimensional superlattice indium selenide photodetector. 9 . The method for preparing a photodetector using two-dimensional superlattice indium selenide according to claim 8 , wherein the surface has a SiO ₂ /Si substrate with two-dimensional superlattice InSe nanosheets. 10 . , the lateral size of the InSe nanosheets on the surface is 20-40 μm, and the thickness is 20-40 nm; under the vacuum conditions, the vacuum degree is 1×10 ^-4 - 5×10 ^-4 Pa; the thickness of the metal chromium electrode is 5-10 nm; the thickness of the metallic gold electrode is 30-50 nm.

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