Controlled Synthesis And Characterization Of Bi₂Te₃One-Dimensional Nanostructures

Bismuth telluride (Bi2Te3) is famous for near-room-temperature thermoelectric effect, however, research on Bi2Te3has attracted much interest because it is predicted to be three-dimensional (3D) topological insulator (TIS). In TIS, the nondegenerate spins surface will make it become dissipationless electronics and spintronics applications. Nanoscal topological insulator materials have a lager surface-to-volume ratio that can manifest the conductive surface states. At present, a large number of theoretical works have emerged in the field of TIS, but in the field of testing progress is relatively slow. One of the main reasons for the samples of TLS is difficult to obtain high quality, therefore, preparing high purity Bi2Te3one-dimensional nanostructures is an important research direction in the fired of nanotechnology. This section is also based on this idea to explore.In this paper, high purity Bi2Te3power as source materials and argon gas as protecting gas, by controlling the material growth condition, such as the pressure in the growth chamber, the temperature of source area and collecting area, the flow rate of carrier gas and so on, we have successfully prepared controlled Bi2Te3one-dimensional nanostructures by Au-catalyzed vapor-liquid-solid(VLS) The morphologies, crystal structure and chemical composition were characterized by using scanning electron microscopy(SEM), X-ray diffraction(XRD), spectrometry and transmission electron microscopy(TEM). The main contents and results are as follows:1Under the other condition of experimental conditions are the same situation, we find that the products on the clean silicon are Bi2Te3sheet or block structure, while products on the silicon with gold film are Bi2Te3one-dimensional nanostructures. So, we can find that the growth direction of Bi2Te3is limited when we use Nano gold a catalyst.2We investigate the effect of carrier gas on morphologies, and then we find that when the carrier gas flow rate increases, the diameter of the Bi2Te3one-dimensional nanostructures increases and more block structure emerges.3We also explore the effect of collecting temperature, we find that when collecting temperature rise, the proportion of bulk materials in the product magnify.