A bismuth-based topological insulator material and preparation method thereof

Abstract

The invention belongs to the technical field of insulator materials, and specifically relates to a bismuth-based topological insulator material and a preparation method thereof. The preparation methodcomprises the following steps: S1, uniformly mixing silicon dioxide powder, sodium hydroxide powder, boron oxide powder, bismuth-source compound powder and chalcogen element powder according to a molar ratio is 4: 4: 1: (0.05-0.5): (0.05-0.5) so as to obtain a mixture A; S2, melting the mixture A at a high temperature of 900 to 1100 DEG C, and carrying out cooling to a room temperature so as to obtain the bismuth-based topological insulator material; and S3, mixing the bismuth-based topological insulator material obtained in the step S2 with isopropyl alcohol, carrying out grinding so as to obtain bismuth-based topological insulator material powder, then dispersing the bismuth-based topological insulator material powder into isopropyl alcohol, and carrying out ultrasonic dispersion so asto obtain a bismuth-based topological insulator two-dimensional material. The method provided by the invention realizes natural growth of a crystal in a glass melt through a high-temperature glass melting method and utilization of low-cost raw materials, and realizes preparation of high-quality layered bismuth-based topological insulator binary and multiple system materials.

Description

technical field [0001] The invention belongs to the technical field of insulator materials, and in particular relates to a bismuth-based topological insulator material and a preparation method thereof. Background technique [0002] Bi 2 Te 3 and Bi 2 Se 3 It is a very powerful material system. As early as the 1950s, researchers discovered that Bi 2 Te 3 The system alloy compound has high electrical conductivity and low thermal conductivity, and has always been a research hotspot in the field of thermoelectricity; in the 1960s, it was reported that this system can be used for phase change memory to read and write data. Based on the application of these two aspects, for Bi 2 Te 3 and Bi 2 Se 3 The research on the preparation of has been carried out for decades, including solid melting, magnetron sputtering, solvothermal and other methods. But it is worth noting that in previous applications, especially as thermoelectric materials, the performance of the material doe...

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Problems solved by technology

[0005] These preparation methods are expensive in equipment, expensive in raw material cost, harsh in process, and complicated in operation; and they have low yield, poor quality, and low crystallinity; and at the same time, impurities will inevitably be introduced to cover up the low-dimensional Bi 2 Se 3 / Bi 2 Te 3 The topological insulation properties of

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