Thermal and Electrical Conduction of Single-crystal Bi₂Te₃ Nanostructures grown using a one step process

摘要

Single-crystal Bi₂Te₃ nanowires (NWs) and nanoribbons (NRs) were synthesized by a vapor-liquid-solid (VLS) method from Bi₂Te₃ powder. To investigate the thermal properties of the Bi₂Te₃ nanostructure, a nondestructive technique based on temperature dependent Raman mapping was carried out. The Raman peaks were red shifted with increasing temperature. In addition, the fraction of the laser power absorbed inside the Bi₂Te₃ nanostructures was estimated by optical simulation and used to calculate the thermal conductivity value (κ). The thermal conductivity value obtained for the Bi₂Te₃ NW and NR was 1.47?Wm?1K?1 and 1.81?Wm?1K?1 at 300?K, respectively. The electrical conductivity of the Bi₂Te₃ nanostructure was also measured. In particular, an excellent electrical conductivity value of 1.22?*?103?Ω?1 cm ?1 was obtained for the Bi₂Te₃ NW at 300?K. This result can be attributed to topological insulator surface states. As a result of our study, the figure of merit (ZT) for the Bi₂Te₃ NW and NR can be significantly improved.