A CdSe@Ti3C2T x Applications of MXene heterojunction materials in semiconductor devices

Abstract

This invention relates to a CdSe@Ti3C2T x The application of MXene heterojunction materials in semiconductor devices, including one of field-effect transistors, photodetectors, supercapacitors, and water electrolysis catalytic devices. This invention utilizes CdSe@Ti3C2T... x The excellent electrical and optical properties of MXene heterojunction materials enable the fabrication of high-performance field-effect transistors, photodetectors, supercapacitors, and water electrolysis devices. The methods are simple, easy to implement, and low in cost, making them suitable for large-scale production applications.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor device technology, and specifically relates to a CdSe@Ti3C2T x Applications of MXene heterojunction materials in semiconductor devices. Background Technology

[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, the hydrogen production performance of CdSe alone remains unsatisfactory due to the rapid recombination of photogenerated carriers. To address this issue, a novel MXene material (Ti3C2T) has been developed. x Due to its excellent conductivity, hydrophilicity, large ultrathin two-dimensional interface, and numerous active sites on its surface, Ti3C2T can promote charge-carrier separation of CdSe. Therefore, two-dimensional Ti3C2T was prepared from layered Ti3AlC2 through in-situ etching with LiF and HCl followed by solvent stripping. x MXene nanosheets. Then, CdSe nanoparticles were immobilized on Ti3C2T using an in-situ hydrothermal method. x On MXene, a series of different Ti3C2T were synthesized. x The CdSe / MXene nanocomposite material has a high content. However, its application as a photocatalyst is currently only publicly disclosed, and there are no reports on its use 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, through the utilization of CdSe@Ti3C2T x The excellent electrical and optical properties of MXene heterojunction materials enable the fabrication of high-performance field-effect transistors, photodetectors, supercapacitors, and water electrolysis devices. The methods are simple, easy to implement, and low in cost, making them suitable for large-scale production applications.

[0004] This invention provides a CdSe@Ti3C2T x Application of MXene heterojunction materials in semiconductor devices, including 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 CdSe nanoparticles in an MXene nanosheet solution to form a CdSe / MXene semiconductor composite material; and performing post-processing on the composite material.

[0006] The specific preparation steps are as follows:

[0007] Step 1: Prepare MXene nanosheets. Disperse MXene precursor powder in an appropriate amount of solvent, and obtain an MXene nanosheet solution through steps such as ultrasonic treatment and centrifugation.

[0008] Step 2: Synthesis of CdSe nanoparticles. CdSe nanoparticles are synthesized under suitable conditions using methods such as hydrothermal, solvothermal, or chemical vapor deposition.

[0009] Step 3: Constructing the CdSe / MXene composite material. CdSe nanoparticles are uniformly dispersed in an MXene nanosheet solution. Through electrostatic adsorption, chemical bonding, or physical mixing, the CdSe nanoparticles are firmly attached to the surface of the MXene nanosheets to form a CdSe / MXene semiconductor composite material.

[0010] Step 4: Post-treatment. The composite material is washed, dried, and annealed to improve its stability and electrochemical properties.

[0011] Furthermore, the semiconductor device is a field-effect transistor, including a source, a drain, a gate, and a channel; the channel material is CdSe@Ti3C2T. x MXene heterojunction materials. During the fabrication process, the size and distribution of CdSe nanoparticles are optimized by controlling the growth time and reaction temperature, thereby improving electron mobility and device on / off ratio.

[0012] Furthermore, the semiconductor device is a photodetector, comprising a light absorption layer, electrodes, and a photoelectric conversion layer; the material of the photoelectric conversion layer is CdSe@Ti3C2T. x MXene heterojunction material, Ti3C2T x MXene serves as a highly efficient conductive matrix, with CdSe nanoparticles distributed on it providing additional electrochemical active sites. The ion transport layer can be either an organic or inorganic electrolyte. Optimization of CdSe and Ti3C2T... x The heterojunction interface of MXene improves the electrochemical performance of capacitors. CdSe@Ti3C2T can be applied using solution or spray methods. x MXene heterojunction materials were fabricated on current collectors, and the interfacial bonding quality and electrical conductivity were improved by annealing.

[0013] Preferably, the light-absorbing layer material is CdSe, which absorbs photons to generate electron-hole pairs, or Ti3C2T. x MXene, as an electrode material, provides an efficient electron conduction pathway. CdSe@Ti3C2T can be applied using solution methods or spin coating.x MXene heterojunction material is coated on a substrate, and the photoelectric response performance of the material is enhanced through subsequent heat treatment steps.

[0014] Furthermore, the semiconductor device is a supercapacitor, comprising an electrode material layer, an ion transport layer, and a current collector; the electrode material layer is made of CdSe@Ti3C2T. x MXene heterojunction material, Ti3C2T x MXene serves as a highly efficient conductive matrix, with CdSe nanoparticles distributed on it providing additional electrochemical active sites. The ion transport layer can be either an organic or inorganic electrolyte. Optimization of CdSe and Ti3C2T... x The heterojunction interface of MXene improves the electrochemical performance of capacitors. CdSe@Ti3C2T can be applied using solution or spray methods. x MXene heterojunction materials were fabricated on current collectors, and the interfacial bonding quality and electrical conductivity were improved by annealing.

[0015] Furthermore, the semiconductor device is a water electrolysis catalytic device, comprising a catalytic layer and an electrode; the catalytic layer is made of CdSe@Ti3C2T. x MXene heterojunction material, CdSe as a catalyst to promote water splitting reaction, Ti3C2T x MXene provides the conductive pathway. Catalytic performance and electrolysis efficiency are optimized by controlling the size and distribution of CdSe nanoparticles. CdSe@Ti3C2T nanoparticles can be applied using solution or spray methods. x MXene heterojunction material is coated onto the electrolyzer electrode, and its stability and catalytic activity are enhanced through subsequent heat treatment steps.

[0016] Beneficial effects

[0017] This invention utilizes CdSe@Ti3C2T x The excellent electrical and optical properties of MXene heterojunction materials enable the fabrication of high-performance field-effect transistors, photodetectors, supercapacitors, and water electrolysis devices. The methods are simple, easy to implement, and low in cost, making them suitable for large-scale production applications. Attached Figure Description

[0018] Figure 1 CdSe@Ti3C2T prepared in Example 1 x A schematic diagram of the fabrication of MXene heterojunction materials.

[0019] Figure 2 CdSe@Ti3C2T prepared in Example 1 x SEM image of MXene heterojunction material.

[0020] Figure 3 shows the CdSe@Ti3C2T prepared in Example 1. x XRD pattern (a) and Raman spectrum (b) of MXene heterojunction material.

[0021] Figure 4 CdSe@Ti3C2T prepared in Example 1 x Schematic diagram of the structural principle of MXene heterojunction material applied to photodetectors.

[0022] Figure 5 CdSe@Ti3C2T prepared in Example 1 x Electrochemical performance testing of MXene heterojunction materials.

[0023] Figure 6 CdSe@Ti3C2T prepared in Example 1 x The principle and performance test diagram of MXene heterojunction material applied to supercapacitors.

[0024] Figure 7 CdSe@Ti3C2T prepared in Example 1 x Performance test diagram of MXene heterojunction material applied to water electrolysis catalytic device. Detailed Implementation

[0025] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0026] Example 1

[0027] 1.CdSe@Ti3C2T x Preparation of MXene heterojunction materials:

[0028] ①Ti3C2T x MXene nanosheets were prepared by etching with hydrofluoric acid.

[0029] First, weigh 1 gram of Ti3AlC2 (MAX phase) powder and slowly add 10 mL of hydrofluoric acid to a polytetrafluoroethylene (PTFE) beaker. The reaction is carried out in a water bath at 40°C and 500 rpm for 24 hours. After the reaction, the solution is poured into a centrifuge tube and centrifuged at 4200 rpm for 3 minutes. The centrifuged solution is washed several times with deionized water, and finally filtered through a pump until all water is removed. Finally, it is freeze-dried for 24 hours. The reaction is carried out at 40°C for 24 hours at 500 rpm to obtain Ti3C2T. xMXene nanosheets.

[0030] ② Synthesis of CdSe nanorods.

[0031] Solution A was prepared by mixing 0.366 g of cadmium chloride with 50 mL of deionized water for 25 minutes, while solution B was prepared by mixing 0.272 g of selenium powder with 40 mL of unsymmetrical dimethylhydrazine solution for 25 minutes. Solutions A and B were then mixed for 15 minutes to ensure complete mixing. The mixture was then transferred to a 100 mL PTFE-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. Finally, the precipitate was freeze-dried for 24 hours to obtain cadmium selenide nanoparticles.

[0032] ③ The preparation method for obtaining cadmium selenide solution is exactly the same as described above. At the end of the above reaction, the cadmium selenide mixed solution is reacted with 4 mL of Ti3C2T... x The MXene solution was mixed and stirred at 25°C for 1 hour to obtain a new mixed solution. This solution was then transferred to a high-pressure reactor 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 then lyophilized for 24 hours to obtain the final precipitate. The final precipitate was lyophilized for 24 hours to obtain CdSe nanorods and Ti3C2T. x A mixture of nanosheets.

[0033] 2. Figure 3a CdSe@Ti3C2T is provided x XRD patterns of MXene were obtained. Specific crystal phases of the material (e.g., (111), (220), (311), etc.) were identified through the XRD patterns. The successfully prepared material exhibited characteristic diffraction peaks corresponding to the expectations. Furthermore, the sharp and high-intensity diffraction peaks in the XRD patterns indicate clarity and intensity, reflecting the characteristics of the CdSe@Ti3C2T semiconductor material. x The high crystal quality of MXene was demonstrated. The lattice parameters of the material were calculated using diffraction angles and compared with literature values, verifying the successful preparation of the material.

[0034] Figure 3b The characteristic peaks appearing in the Raman spectrum were compared with those of the known semiconductor material CdSe (approximately 200 cm⁻¹). -1 and 600cm -1 The peaks confirmed the successful preparation of the composite material. MXene characteristic peaks: Characteristic peaks related to MXene (such as MO bond-related peaks) may also be seen in the Raman spectrum, indicating the preservation of the MXene structure.

[0035] 3. Figure 4CdSe@Ti3C2T is provided x Schematic diagram of the structural principle of MXene heterojunction material applied to photodetectors. When light shines on CdSe@Ti3C2T... x In heterojunctions, photons are absorbed and excited electrons in the semiconductor to transition from the valence band to the conduction band, generating electron-hole pairs. This is due to the interaction between CdSe and Ti3C2T. x Due to the band structure difference, electrons and holes will separate at the heterojunction interface. Specifically: electrons may separate due to the band structure difference between Ti3C2T. x The conduction band energy is lower and the conduction band shifts from CdSe to Ti3C2T. x Holes, on the other hand, may remain in the valence band of CdSe or migrate to another electrode, depending on the work function and band structure of the electrode. This separation and collection of electrons and holes generates a photocurrent, thus enabling photodetection. The photocurrent changes with varying light intensity, allowing the detection of the optical signal by measuring the photocurrent. In summary, CdSe@Ti3C2T x Heterojunction materials, through their unique band structure and photoelectric properties, have enabled efficient photoelectric conversion and signal detection in photodetectors.

[0036] 4. Figure 5 CV, GCD, and stability testing are three commonly used techniques in electrochemical research, providing crucial information about the performance of electrode materials or supercapacitors. By comparing the areas under the CV curves, the charge storage capacities were found to be, in descending order, CdSe@Ti3C2T. x >CdSe>MXene indicates that the semiconductor material CdSe is significantly different from Ti3C2T. x The composite exhibits excellent charge storage per unit volume. Comparison of discharge times reveals that CdSe@Ti3C2T... x It can provide the highest specific capacity.

[0037] 5. Figure 6 A comprehensive performance analysis of supercapacitors, using CV, GCD, and impedance measurements, revealed that the band structure of CdSe determines its semiconductor properties, including the band gap, conduction band, and valence band positions. These properties significantly influence the charge storage and transport performance of CdSe in supercapacitors. The metallic conductivity of MXene is closely related to its band structure; its broad conduction band and valence band overlap facilitate electron transport, resulting in supercapacitors composed of MXene exhibiting high capacitance.

[0038] 6. Figure 7As shown, in water electrolysis applications, the rich interface, numerous active sites, and strong interactions and synergistic effects between the semiconductor materials CdSe and MXene make CdSe@Ti3C2T x The composite catalyst exhibits significant catalytic activity for the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) in alkaline electrolytes. CdSe@Ti3C2T x Composite materials at 10mA cm -2 At the given current density, the overpotentials of HER and OER are 201 mV and 273 mV, respectively, and the Tafel slope is 196 mVdec. -1 and 62mVdec -1 Both exhibit superior catalytic activity compared to individual CdSe and MXene materials. Their exceptional catalytic activity is attributed to the carefully designed structure between CdSe and MXene, and the constructed heterojunction interface, which promotes greater specific surface area, mass and charge transfer, as well as an optimized electronic structure, providing new insights for the design of future high-efficiency water electrolysis.

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, and a supercapacitor. The CdSe@Ti3C2T x The preparation methods of MXene heterojunction materials include: Preparation of MXene nanosheets: Weigh 1 gram of Ti3AlC2 (MAX phase) powder and slowly add 10 mL of hydrofluoric acid to a polytetrafluoroethylene (PTFE) cup; the reaction is carried out in a water bath at 40°C and 500 rpm for 24 hours; after the reaction, pour the solution into a centrifuge tube and centrifuge at 4200 rpm for 3 minutes. The centrifuged solution is washed several times with deionized water, and finally filtered with a pump until the water is completely removed. Finally, it is freeze-dried for 24 hours; the reaction is carried out at 40°C for 24 hours at 500 rpm to obtain Ti3C2T x MXene nanosheets; Synthesis of CdSe nanoparticles: 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 unsymmetrical dimethylhydrazine solution for 25 minutes. Then, solutions A and B were mixed for 15 minutes to ensure complete mixing. The mixture was then transferred to a 100 mL polytetrafluoroethylene-lined high-pressure reactor 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 the precipitate. Finally, the precipitate was freeze-dried for 24 hours to obtain cadmium selenide nanoparticles. CdSe nanoparticles were uniformly dispersed in an MXene nanosheet solution to form a CdSe / MXene semiconductor composite material; the composite material was then post-treated.

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

3. The application according to claim 1, characterized in that: The semiconductor device is a photodetector, comprising a light absorption layer, electrodes, and a photoelectric conversion layer; the material of the photoelectric conversion layer is CdSe@Ti3C2T. x MXene heterojunction material.

4. The application according to claim 3, characterized in that: The light-absorbing layer material is CdSe.

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

Images