Application of CdSe-coated Ti < 3 > C < 2 > T < x > MXene heterojunction material in semiconductor device

Abstract

The invention relates to an application of a CdSe-coated Ti < 3 > C < 2 > T < x > MXene heterojunction material in a semiconductor device. The semiconductor device comprises one of a field effect transistor, a photoelectric detector, a super capacitor and an electrolytic water catalytic device. The field effect transistor, the photoelectric detector, the supercapacitor and the water electrolysis device with high performance are prepared by utilizing the excellent electrical and optical characteristics of the CdSe-coated Ti3C2TxMXene heterojunction material, and the method is simple and easy to implement, low in cost and suitable for large-scale production and application.

Description

Technical Field

[0001] The present invention belongs to the technical field of semiconductor devices, and particularly relates to a CdSe@Ti3C2T x Application of MXene heterojunction materials in semiconductor devices. Background Art

[0002] Among various semiconductor photocatalysts, CdSe has attracted much attention due to its suitable band gap, strong absorption in the visible region, and high chemical stability. However, due to the rapid recombination of photogenerated carriers, the hydrogen production performance of CdSe alone is still unsatisfactory. To solve this problem, a new type of MXene material (Ti3C2T x ), due to its excellent conductivity, hydrophilicity, large ultrathin 2D interface and abundant active sites on the surface, which can promote the charge-carrier separation of CdSe. Therefore, 2D Ti3C2T was prepared from layered Ti3AlC2 by in situ etching with LiF and HCl and subsequent solvent stripping. x MXene nanosheets. Then, CdSe nanoparticles were fixed on Ti3C2T x A series of different Ti3C2T x However, the material is currently only used as a photocatalyst, and there is no report on its application in semiconductor devices. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a CdSe@Ti3C2T x The application of MXene heterojunction materials in semiconductor devices is achieved by utilizing CdSe@Ti3C2T x The excellent electrical and optical properties of MXene heterojunction materials can be used to prepare high-performance field-effect transistors, photodetectors, supercapacitors and water electrolysis devices. The method is simple, easy and low-cost, and suitable for large-scale production applications.

[0004] The present invention provides a CdSe@Ti3C2T x Application of MXene heterojunction materials in semiconductor devices, wherein the semiconductor devices include one of field effect transistors, photodetectors, supercapacitors and water electrolysis catalytic devices.

[0005] Preferably, the CdSe@Ti3C2T x The preparation method of MXene heterojunction material includes: preparing MXene nanosheets; synthesizing CdSe nanoparticles; uniformly dispersing the CdSe nanoparticles in a MXene nanosheet solution to form a CdSe / MXene semiconductor composite material; and post-processing the composite material.

[0006] The specific preparation steps are as follows: Step 1: Prepare MXene nanosheets. Disperse MXene precursor powder in an appropriate amount of solvent, and obtain MXene nanosheet solution through ultrasonic treatment, centrifugal separation and other steps.

[0007] Step 2: Synthesize CdSe nanoparticles. Use a hydrothermal method, a solvothermal method or a chemical vapor deposition method to synthesize CdSe nanoparticles under suitable conditions.

[0008] Step 3: Construct CdSe / MXene composite materials. Disperse CdSe nanoparticles evenly in the MXene nanosheet solution, and make the CdSe nanoparticles firmly adhere to the surface of the MXene nanosheets through electrostatic adsorption, chemical bonding or physical mixing to form a CdSe / MXene semiconductor composite material.

[0009] Step 4: Post-treatment: The composite material is washed, dried, annealed, etc. to improve its stability and electrochemical performance.

[0010] Furthermore, the semiconductor device is a field effect transistor, including a source, a drain, a gate and a channel; the material of the channel is CdSe@Ti3C2T x MXene heterojunction material. During the preparation process, the size and distribution of CdSe nanoparticles are optimized by controlling the growth time and reaction temperature, thereby improving the electron mobility and device switching ratio.

[0011] Furthermore, the semiconductor device is a photodetector, comprising a light absorption layer, an electrode and a photoelectric conversion layer; the material of the photoelectric conversion layer is CdSe@Ti3C2T x MXene heterojunction materials, Ti3C2T x MXene is an efficient conductive matrix, and CdSe nanoparticles are distributed on it to provide additional electrochemical active sites. The ion transport layer can be made of organic or inorganic electrolytes. By optimizing the CdSe and Ti3C2T x The heterojunction interface of MXene improves the electrochemical performance of the capacitor. CdSe@Ti3C2T x The MXene heterojunction material was prepared on the current collector and annealed to improve the interface bonding quality and conductivity.

[0012] Preferably, the light absorbing layer material is CdSe, which absorbs photons to generate electron-hole pairs, and Ti3C2T x MXene is used as an electrode material to provide an efficient electron conduction path. CdSe@Ti3C2T xThe MXene heterojunction material is coated on the substrate, and the photoelectric response performance of the material is enhanced through a subsequent heat treatment step.

[0013] Furthermore, the semiconductor device is a supercapacitor, comprising an electrode material layer, an ion transport layer and a current collector; the material of the electrode material layer is CdSe@Ti3C2T x MXene heterojunction materials, Ti3C2T x MXene is an efficient conductive matrix, and CdSe nanoparticles are distributed on it to provide additional electrochemical active sites. The ion transport layer can be made of organic or inorganic electrolytes. By optimizing the CdSe and Ti3C2T x The heterojunction interface of MXene improves the electrochemical performance of the capacitor. CdSe@Ti3C2T x The MXene heterojunction material was prepared on the current collector and annealed to improve the interface bonding quality and conductivity.

[0014] Furthermore, the semiconductor device is a water electrolysis catalytic device, comprising a catalytic layer and an electrode; the material of the catalytic layer is CdSe@Ti3C2T x MXene heterojunction materials, CdSe as a catalyst to promote water splitting reaction, Ti3C2T x MXene provides a conductive path. By controlling the size and distribution of CdSe nanoparticles, the catalytic performance and electrolysis efficiency can be optimized. CdSe@Ti3C2T x The MXene heterojunction material is coated on the electrolyzer electrodes, and a subsequent heat treatment step is performed to enhance the material's stability and catalytic activity.

[0015] Beneficial Effects The present invention utilizes CdSe@Ti3C2T x The excellent electrical and optical properties of MXene heterojunction materials can be used to prepare high-performance field-effect transistors, photodetectors, supercapacitors and water electrolysis devices. The method is simple, easy and low-cost, and suitable for large-scale production applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 For the preparation of CdSe@Ti3C2T in Example 1 x Schematic diagram of the preparation of MXene heterojunction materials.

[0017] Figure 2 For the preparation of CdSe@Ti3C2T in Example 1 x SEM image of MXene heterojunction material.

[0018] Figure 3 shows the preparation of CdSe@Ti3C2T in Example 1x XRD pattern (a) and Raman spectrum (b) of MXene heterojunction materials.

[0019] Figure 4 For the preparation of CdSe@Ti3C2T in Example 1 x Structural schematic diagram of MXene heterojunction materials used in photodetectors.

[0020] Figure 5 For the preparation of CdSe@Ti3C2T in Example 1 x Electrochemical performance test of MXene heterojunction materials.

[0021] Figure 6 For the preparation of CdSe@Ti3C2T in Example 1 x The principle and performance test diagram of MXene heterojunction materials used in supercapacitors.

[0022] Figure 7 For the preparation of CdSe@Ti3C2T in Example 1 x Performance test diagram of MXene heterojunction material applied to water electrolysis catalytic devices. DETAILED DESCRIPTION

[0023] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0024] Example 1 1. CdSe@Ti3C2T x Preparation of MXene heterojunction materials: ①Ti3C2T x MXene nanosheets were prepared by hydrofluoric acid etching.

[0025] First, weigh 1 gram of Ti3AlC2 (MAX phase) powder and slowly add 10 ml of hydrofluoric acid into a polytetrafluoroethylene cup. The reaction was carried out in a water bath at 40°C and 500 rpm for 24 hours. After the reaction, the solution was poured into a centrifuge tube and centrifuged at 4200 rpm for 3 minutes. The centrifuged solution was washed several times with deionized water and finally filtered with a pump until the water was completely removed. Finally, it was freeze-dried for 24 hours. The reaction was carried out at 40°C for 24 hours and the speed was 500 rpm to obtain Ti3C2T x MXene nanosheets.

[0026] ②Synthesis of CdSe nanorods.

[0027] Solution A was formed by mixing 0.366 g of cadmium chloride with 50 ml of deionized water for 25 minutes, while solution B was formed by mixing 0.272 g of selenium powder with 40 ml of UDMH solution for 25 minutes. Then, solution A and solution B were mixed for 15 minutes to ensure complete mixing, and then the mixed solution was transferred to a 100 ml polytetrafluoroethylene-lined autoclave and heated to 180 ° C for 6 hours. After the reaction, the solution was centrifuged three times and washed three times with deionized water to obtain a precipitate, and finally freeze-dried for 24 hours to obtain cadmium selenide nanoparticles.

[0028] ③ The preparation method obtained the cadmium selenide solution in exactly the same way as the above process. At the end of the above reaction, the cadmium selenide mixed solution obtained was mixed with 4 ml of Ti3C2T x The MXene solutions were mixed and stirred at 25 °C for 1 hour to obtain a new mixed solution. It was then transferred to an autoclave and heated to 100 °C for 12 hours. Subsequently, it was centrifuged three times and washed with deionized water and ethanol to obtain a precipitate, which was finally freeze-dried for 24 hours to obtain a precipitate. The final precipitate was freeze-dried for 24 hours to obtain CdSe nanorods and Ti3C2T x Mixed products of nanosheets.

[0029] 2. Figure 3a Provides CdSe@Ti3C2T x XRD spectrum of MXene. Through the XRD spectrum, the specific crystalline phases of the material (e.g., (111), (220), (311), etc.) were identified. The successfully prepared material showed characteristic diffraction peaks corresponding to expectations. At the same time, the sharp and high-intensity diffraction peaks in the XRD spectrum reflect the clarity and intensity of the semiconductor material CdSe@Ti3C2T x The high crystalline quality of MXene. The lattice parameters of the material were calculated by diffraction angle and compared with the literature values, verifying the successful preparation of the material.

[0030] Figure 3b The characteristic peaks in the Raman spectrum were compared with those of the known semiconductor material CdSe (approximately 200 cm -1 and 600cm -1 MXene characteristic peaks: MXene-related characteristic peaks (such as MO bond-related peaks) may also be seen in the Raman spectrum, indicating the preservation of the MXene structure.

[0031] 3. Figure 4 Provides CdSe@Ti3C2T x Schematic diagram of the structure of MXene heterojunction materials used in photodetectors. When light shines on CdSe@Ti3C2Tx When the photons are absorbed at the heterojunction, they excite the electrons in the semiconductor to jump from the valence band to the conduction band, generating electron-hole pairs. x Due to the energy band difference between the two, electrons and holes will separate at the heterojunction interface. Specifically: electrons may be separated by Ti3C2T x The conduction band energy of CdSe is lower and transfers to Ti3C2T x , while holes may remain in the valence band of CdSe or transfer to another electrode, depending on the work function and band structure of the electrode. This separation and collection process of electrons and holes generates photocurrent, thus realizing the function of photodetection. When the light intensity changes, the photocurrent will also change accordingly, so the light signal can be detected by measuring the photocurrent. In general, CdSe@Ti3C2T x Heterojunction materials achieve efficient photoelectric conversion and signal detection in photodetectors through their unique band structure and optoelectronic properties.

[0032] 4. Figure 5 CV, GCD and stability testing are three commonly used techniques in electrochemical research, which can provide important information about the performance of electrode materials or supercapacitors. By comparing the areas of the CV curves, it is found that the charge storage capacity is CdSe@Ti3C2T x >CdSe>MXene, indicating that the semiconductor material CdSe and Ti3C2T x The composite has an excellent charge storage level per unit volume. By comparing the discharge time, it can be found that CdSe@Ti3C2T x Can provide the highest specific capacity.

[0033] 5. Figure 6 The comprehensive performance analysis of supercapacitors, through CV, GCD and impedance tests, shows that the band structure of CdSe determines its semiconductor properties, including the band gap width, the position of the conduction band and the valence band. These properties can well affect the charge storage and transfer performance of CdSe in supercapacitors. The metallic conductivity of MXene is closely related to its band structure. Its wide conduction band and valence band overlap allows electrons to be easily transferred between them, resulting in a supercapacitor composed of it having a higher capacity.

[0034] 6. Figure 7 As shown in the figure, in the application of water electrolysis, the rich interface, numerous active sites, strong interaction and synergistic effect between the semiconductor material CdSe and MXene make CdSe@Ti3C2T xThe composite catalyst exhibits significant catalytic activity for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline electrolyte. x The composite material was -2 At a current density of 2.3 Å, the overpotentials of HER and OER are 201 mV and 273 mV, respectively, and the Tafel slope is 196 mVdec. -1 and 62mVdec -1 , which are superior to individual CdSe and MXene materials. Its excellent catalytic activity is attributed to the carefully designed structure and constructed heterojunction interface between CdSe and MXene, which promotes a larger specific surface area, mass and charge transfer, as well as an optimized electronic structure, providing new ideas for the design of efficient water electrolysis in the future.

Claims

1. A CdSe@Ti3C2T x The application of MXene heterojunction materials in semiconductor devices is characterized by: The semiconductor device includes one of a field effect transistor, a photodetector, a super capacitor and a water electrolysis catalytic device.

2. CdSe@Ti3C2T according to claim 1 x The application of MXene heterojunction materials in semiconductor devices is characterized by: The CdSe@Ti3C2T x The preparation method of MXene heterojunction material includes: preparing MXene nanosheets; synthesizing CdSe nanoparticles; uniformly dispersing the CdSe nanoparticles in a MXene nanosheet solution to form a CdSe / MXene semiconductor composite material; and post-processing the composite material.

3. CdSe@Ti3C2T according to claim 1 x The application of MXene heterojunction materials in semiconductor devices is characterized by: The semiconductor device is a field effect transistor, including a source, a drain, a gate and a channel; the material of the channel is CdSe@Ti3C2T x MXene heterojunction materials.

4. CdSe@Ti3C2T according to claim 1 x The application of MXene heterojunction materials in semiconductor devices is characterized by: The semiconductor device is a photodetector, including a light absorption layer, an electrode and a photoelectric conversion layer; the material of the photoelectric conversion layer is CdSe@Ti3C2T x MXene heterojunction materials.

5. CdSe@Ti3C2T according to claim 4 x The application of MXene heterojunction materials in semiconductor devices is characterized by: The material of the light absorption layer is CdSe.

6. The CdSe@Ti3C2T3 according to claim 1 x The application of MXene heterojunction materials in semiconductor devices is characterized by: The semiconductor device is a supercapacitor, comprising an electrode material layer, an ion transport layer and a current collector; the material of the electrode material layer is CdSe@Ti3C2T x MXene heterojunction materials.

7. The CdSe@Ti3C2T3 according to claim 1 x The application of MXene heterojunction materials in semiconductor devices is characterized by: The semiconductor device is a water electrolysis catalytic device, including a catalytic layer and an electrode; the material of the catalytic layer is CdSe@Ti3C2T x MXene heterojunction materials.

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