Preparation method of zirconium pentatelluride film

Abstract

The invention discloses a preparation method of a zirconium pentatelluride film, which specifically comprises the following steps: firstly, growing ZrTe5 crystals by a fluxing agent method, grinding the ZrTe5 crystals into powder, and adding a dispersing agent for intercalation treatment to weaken Van der Waals' force between layers of the ZrTe5 crystals; and then an ultrasonic dispersion technology is adopted to prepare a ZrTe5 dispersion liquid with good dispersibility. In order to improve the stability of the dispersion liquid, a stabilizer is further added, so that the dispersion degree and the stability of ZrTe5 particles in the solution are remarkably enhanced. And finally, realizing uniform deposition of the thin film through a spin coating or dispensing technology. The method is easy and convenient to operate, low in cost and suitable for preparation and application of topological functional materials.

Description

Technical Field

[0001] The invention relates to the technical field of nano material preparation and describes a method for preparing a zirconium pentatelluride film. Background Art

[0002] Topological materials are currently a frontier research object that has attracted widespread attention in the fields of condensed matter physics and materials science. Unlike traditional materials, topological materials have the characteristics of bulk insulation and boundary state conductivity under the action of strong spin-orbit coupling. This novel electronic topological property makes topological materials have certain application potential in spin electronics, quantum computing, and low-power electronic devices. With the miniaturization of electronic devices, research on two-dimensional topological materials is increasing. Two-dimensional topological materials have unique properties such as one-dimensional topological boundary states and quantum spin Hall effect, which make them show higher stability, integration and unique application potential in dissipative electron transport and nanoelectronics. As a star material among two-dimensional topological materials, ZrTe5 has attracted much attention because of its topological insulator, thermoelectric material and quantum transport properties.

[0003] The energy gap characteristics of ZrTe5 are complex and changeable, and are significantly affected by factors such as crystal structure, temperature and pressure. At room temperature, ZrTe5 is a narrow-bandgap semiconductor with high mid-infrared light absorption capacity and excellent thermoelectric properties. It shows broad application prospects in optoelectronic devices, flexible thermoelectric materials, and wearable power generation or temperature difference sensing. Under low temperature conditions, due to the energy gap approaching zero or even the occurrence of energy band overlap, ZrTe5 phase changes to a topological Dirac semimetal with extremely high electron mobility, significant spin-orbit coupling and quantum transport properties, which is suitable for the research and development of quantum computing, high-performance sensors and topological electronic devices. In addition, the dynamic regulation ability of ZrTe5 enables it to achieve flexible switching of electronic states under external excitation (such as pressure and magnetic field), further expanding its functional applications. The excellent physical and chemical properties make ZrTe5 one of the research focuses of new functional materials.

[0004] At present, ZrTe5 thin films are mainly prepared by mechanical exfoliation. Although the mechanical exfoliation method is simple to operate and low in cost, it is impossible to obtain large-scale thin films of uniform thickness at the millimeter level due to the quasi-one-dimensional linear and strip-shaped structure of ZrTe5. Therefore, large-scale preparation of highly crystalline ZrTe5 thin films is urgently needed.

[0005] Therefore, the preparation of topological material dispersions based on the solution method has become a feasible alternative. By depositing the uniformly dispersed topological material dispersion on the substrate, a thin film with few surface defects and uniform and dense structure can be obtained. At present, the main methods for preparing topological material dispersions include liquid phase dispersion, chemical dispersion, electrochemical dispersion, and mechanical ball milling. Among them, the liquid phase dispersion method has become the preferred method for preparing topological material dispersions due to its simplicity, low cost and high efficiency. Through liquid phase dispersion, a topological material dispersion with high crystallinity, few defects and excellent electrical properties can be obtained. The film prepared using this dispersion shows broad application prospects in the fields of flexible electronic devices, optoelectronic devices, sensors, and energy storage and conversion. However, ZrTe5 particles have poor stability during solution dispersion and it is difficult to achieve a high-uniformity film. Summary of the invention

[0006] The purpose of the present invention is to prepare a stable ZrTe5 dispersion using a liquid phase ultrasonic dispersion technology with simple operation process and low cost, and further realize uniform thin film deposition by a spin coating or drop coating method.

[0007] The specific technical solution for achieving the purpose of the present invention is: A method for preparing a zirconium pentatelluride thin film comprises the following specific steps: (1) Growth of ZrTe5 crystals: Zr and Te powders are placed in a quartz tube at a molar ratio of 1:45-50 and sealed in a vacuum tube. The tube is then placed in a muffle furnace and the temperature is set at 950-1100 °C for 20-30 h to allow the mixture to fully melt and form a uniform Zr-Te melt. The temperature is then lowered in two stages: the first stage is rapid cooling at 600-650 °C; the second stage is slow cooling at 450-500 °C until the crystal growth is complete. (2) Preparing a ZrTe5 dispersion: crushing the ZrTe5 crystals grown in step (1) into powder in an agate mortar; placing the ZrTe5 powder in a container, adding a dispersant and mixing uniformly; placing the mixture in an ultrasonic processor to achieve dispersion to obtain a ZrTe5 dispersion, and then adding a stabilizer to the dispersion to allow it to be fully mixed; wherein the dispersant is selected from one or more of 1-pyrenesulfonic acid sodium salt, 2-hydroxy-7-naphthalenesulfonic acid sodium salt, dimethyl sulfoxide, N-methylpyrrolidone and N,N-dimethylformamide; when 1-pyrenesulfonic acid sodium salt or 2-hydroxy-7-naphthalenesulfonic acid sodium salt is used as a dispersant, deionized water is added as a solvent; ZrTe5, 1-pyrenesulfonic acid sodium salt or 2-hydroxy-7-naphthalenesulfonic acid sodium salt and deionized water are prepared according to a ratio of 5 mg: 1 ~ 2 mg: 1 ~ 2 mL; using dimethyl sulfoxide, N-methylpyrrolidone or N When N-dimethylformamide is used as the dispersant, the concentration of ZrTe5 dispersion is 1-10 mg / mL; the stabilizer is pinene alcohol or oleylamine, wherein the volume ratio of ZrTe5 dispersion to the stabilizer is 10:1; the ultrasonic power is 100-120 W, and the ultrasonic temperature is maintained at 20-40 °C; (3) Preparing a ZrTe5 thin film: coating the ZrTe5 dispersion prepared in step (2) onto a substrate by spin coating or drop coating to form a ZrTe5 thin film, and then subjecting the ZrTe5 thin film to vacuum annealing and cooling to room temperature to obtain the zirconium pentatelluride thin film; the vacuum annealing has a temperature of 60 to 120 °C and an annealing time of 5 to 30 min.

[0008] Furthermore, the substrate is a silicon / silicon dioxide substrate, an aluminum oxide substrate or a conductive glass; wherein the substrate is cleaned with deionized water, acetone and isopropanol before spin coating or drop coating.

[0009] A zirconium pentatelluride film prepared based on the above method.

[0010] The invention prepares ZrTe5 dispersion liquid based on liquid phase ultrasonic dispersion technology, has simple preparation process and low cost; the prepared thin film has high crystallinity, relatively few defects and good electrical properties.

[0011] In addition, the two-dimensional ZrTe5 particles after ultrasonic dispersion have a very high specific surface area, and the van der Waals force between the layers makes the ZrTe5 particles in the dispersion liquid easy to settle and agglomerate, and the prepared ZrTe5 dispersion liquid is unstable. In the present invention, the dispersion degree of the ZrTe5 dispersion liquid is adjusted by adding a stabilizer, so that it has good dispersibility and is not prone to agglomeration or sedimentation. At the same time, the uniformity of film deposition is significantly improved, and high-quality ZrTe5 films can be directly prepared on the substrate using a spin coating or drop coating process. In addition, by adjusting the spin coating speed and time, the thickness of the ZrTe5 film can also be accurately controlled, thereby laying a solid foundation for its application in electronic devices and related fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a flow chart of the present invention; Figure 2 Schematic diagram of the ZrTe5 dispersion prepared by the present invention; Figure 3 These are optical microscope images of the ZrTe5 thin film obtained in Example 1 of the present invention at different magnifications. DETAILED DESCRIPTION

[0013] The present invention provides a method for preparing a zirconium pentatelluride thin film. In order to make the purpose, technical solution and advantages of the present invention clearer, the present invention will be described in more detail below. It should be particularly noted that the specific embodiments described herein are only used to illustrate and explain the content of the present invention and do not limit the scope of the present invention.

[0014] The invention prepares a stable ZrTe5 dispersion liquid by adding a suitable dispersant and using a liquid phase ultrasonic dispersion technology, and the operation process is simple and the cost is low. In addition, the use of a suitable stabilizer is conducive to improving the dispersion degree and stability of ZrTe5 particles in the dispersion liquid, so that uniform thin film deposition can be directly achieved by a spin coating method or a drop coating method.

[0015] The present invention provides the following embodiments to provide a more complete understanding of the present invention.

[0016] The ZrTe5 crystals described in the following examples are all prepared by the following solvent method. Zr and Te single-substance powders are placed in a quartz tube at a molar ratio of 1:45~50 and vacuum-sealed; then placed in a muffle furnace, the temperature is set to 950~1100℃, and the insulation time is 20~30 hours to fully melt the mixture and form a uniform Zr-Te melt; then the temperature is cooled in two stages, the first stage is rapid cooling, the temperature is 600~650℃; the second stage is slow cooling, the temperature is 450~500℃, until the crystal growth is completed. Figure 1 shown. Example

[0017] Take 10 mg of flux-grown ZrTe5 crystals and grind them into powder using an agate mortar. Add the ZrTe5 powder and 2 mL of N-methylpyrrolidone into a container, set the temperature of the ultrasonic processor at 30 °C, set the power to 120 W, and ultrasonicate the solution for 4 h to obtain a ZrTe5 dispersion. Add 200 μL of oleylamine and stir in a magnetic stirrer for 5 min. Figure 2 shown.

[0018] The size of the silicon / silicon dioxide substrate was 1 cm × 1 cm and was cut manually using a scriber. It was cleaned with deionized water, acetone, and isopropanol before spin coating. The ZrTe5 dispersion was then spun at a low speed of 300 rpm for 20 s and vacuum annealed at 120 °C for 20 min. The resulting ZrTe5 film was as shown in Figure 2. Figure 3 Shown are optical microscope images of ZrTe5 topological films under different magnifications (scale bar: 0.1 mm). Example

[0019] Take 10 mg of flux-grown ZrTe5 crystals and grind them into powder using an agate mortar. Add the ZrTe5 powder and 5 mL of N,N-dimethylformamide into a container, set the temperature of the ultrasonic processor at 25 °C, set the power to 100 W, and ultrasonicate the solution for 8 h to obtain a ZrTe5 dispersed solution. Add 500 μL of oleylamine as a stabilizer and place it in a magnetic stirrer for stirring for 10 min.

[0020] The silicon / silicon dioxide substrate (alumina substrate size, conductive glass) was 1 cm × 1 cm and was cut manually using a scriber. It was cleaned with deionized water, acetone, and isopropanol before spin coating. The dispersion was then spin-coated on the chip at a constant speed of 500 rpm and vacuum annealed at 120 °C for 20 min. Example

[0021] Take 5 mg of flux-grown ZrTe5 crystals and grind them into powder using an agate mortar. Add the ZrTe5 powder and 2 mL of dimethyl sulfoxide into a container, set the temperature of the ultrasonic processor at 20 °C, set the power to 120 W, and ultrasonicate the solution for 6 h to obtain a ZrTe5 dispersed solution. Add 200 μL of pinene alcohol as a stabilizer and place it in a magnetic stirrer for 15 min.

[0022] The size of the silicon / silicon dioxide substrate and the alumina substrate were both 1 cm × 1 cm, and they were cut manually using a scriber. They were pre-cleaned with deionized water, acetone, and isopropanol before spin coating. Then, an appropriate amount of ZrTe5 dispersion was dropped on the silicon / silicon dioxide substrate (or alumina substrate) with a dropper, dried at room temperature for 20 min, and finally vacuum annealed at 60 °C for 25 min. Example

[0023] Take 5 mg of flux-grown ZrTe5 crystals and grind them into powder using an agate mortar. Add ZrTe5 powder, 1 mL of deionized water and 2 mg of 1-pyrenesulfonic acid sodium salt into a container, set the temperature of the ultrasonic processor at 35°C, set the power to 120 W, and ultrasonicate the solution for 10 h to obtain a ZrTe5 dispersed solution. Then add 100 μL of oleylamine as a stabilizer and place it in a magnetic stirrer for 5 min.

[0024] The conductive glass was 1 cm × 1 cm in size and was cut manually using a scriber. It was pre-cleaned with deionized water, acetone, and isopropanol before spin coating. The dispersion was then spin-coated on the conductive glass at a constant speed of 800 rpm and vacuum annealed at 90 °C for 30 min.

Claims

1. A method for preparing a zirconium pentatelluride thin film, characterized in that: The steps include: (1) Growth of ZrTe5 crystals: Zr and Te powders are placed in a quartz tube at a molar ratio of 1:45-50 and sealed in a vacuum tube. The tube is then placed in a muffle furnace and the temperature is set at 950-1100 °C for 20-30 h to allow the mixture to fully melt and form a uniform Zr-Te melt. The temperature is then lowered in two stages: the first stage is rapid cooling at 600-650 °C; the second stage is slow cooling at 450-500 °C until the crystal growth is complete. (2) Preparing a ZrTe5 dispersion: crushing the ZrTe5 crystals grown in step (1) into powder in an agate mortar; placing the ZrTe5 powder in a container, adding a dispersant and mixing uniformly; placing the mixture in an ultrasonic processor to achieve dispersion to obtain a ZrTe5 dispersion, and then adding a stabilizer to the dispersion to allow it to be fully mixed; wherein the dispersant is selected from one or more of 1-pyrenesulfonic acid sodium salt, 2-hydroxy-7-naphthalenesulfonic acid sodium salt, dimethyl sulfoxide, N-methylpyrrolidone and N,N-dimethylformamide; when 1-pyrenesulfonic acid sodium salt or 2-hydroxy-7-naphthalenesulfonic acid sodium salt is used as a dispersant, deionized water is added as a solvent; ZrTe5, 1-pyrenesulfonic acid sodium salt or 2-hydroxy-7-naphthalenesulfonic acid sodium salt and deionized water are prepared according to a ratio of 5 mg: 1 ~ 2 mg: 1 ~ 2 mL; using dimethyl sulfoxide, N-methylpyrrolidone or N When N-dimethylformamide is used as the dispersant, the concentration of ZrTe5 dispersion is 1-10 mg / mL; the stabilizer is pinene alcohol or oleylamine, wherein the volume ratio of ZrTe5 dispersion to the stabilizer is 10:1; the ultrasonic power is 100-120 W, and the ultrasonic temperature is maintained at 20-40 °C; (3) Preparing a ZrTe5 thin film: coating the ZrTe5 dispersion prepared in step (2) onto a substrate by spin coating or drop coating to form a ZrTe5 thin film, and then subjecting the ZrTe5 thin film to vacuum annealing and cooling to room temperature to obtain the zirconium pentatelluride thin film; the vacuum annealing has a temperature of 60 to 120 °C and an annealing time of 5 to 30 min.

2. The method for preparing a zirconium pentatelluride thin film according to claim 1, characterized in that: The substrate is a silicon / silicon dioxide substrate, an aluminum oxide substrate or a conductive glass; wherein the substrate is cleaned with deionized water, acetone and isopropanol before spin coating or drop coating.

3. A zirconium pentatelluride film prepared by the method according to claim 1.

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