Institute of Electronic Engineering and Nanotechnologies, Academy of Science of Moldova, 2028 Chisinau, Republic of Moldova.
J Phys Condens Matter. 2013 May 22;25(20):205303. doi: 10.1088/0953-8984/25/20/205303. Epub 2013 Apr 25.
We report results on the effect of strain on the thermopower and electrical resistance of glass-coated individual Bi nanowires. Here, we show that there is a critical diameter of wires below which the contribution of holes to the charge transport in pure Bi nanowires is more significant than that of electrons. The properties of Bi nanowires are examined in the light of a strain induced electronic topological transition. At low temperatures, the thermopower dependences on strain exhibit a non-monotonic behavior inherent in thinner wires, where the thermopower is dominated by the diffusion transport mechanism of holes. The hole-dominated transport can be transformed into electron-dominated transport through a smooth manipulation with the phonon spectrum and Fermi surface by applying a uniaxial strain. A fairly high value of the thermoelectric power factor (S(2)/ρ = 89 μW cm(-1) K(-2)) was found in the temperature range of 80-300 K, where the dominant mechanism contributing to the thermopower is diffusive thermoelectric generation with electrons as the majority carrier.
我们报告了应变对涂覆玻璃的单个 Bi 纳米线的热电势和电阻的影响。这里，我们表明，在低于某个临界直径的情况下，空穴对纯 Bi 纳米线中电荷输运的贡献比电子更显著。我们根据应变诱导的电子拓扑相变来研究 Bi 纳米线的性质。在低温下，应变对热电势的依赖关系表现出较细的线材所固有的非单调行为，其中热电势主要由空穴的扩散输运机制决定。通过施加单轴应变，可以通过对声子谱和费米面进行平滑处理，将空穴主导的输运转变为电子主导的输运。在 80-300 K 的温度范围内，发现了相当高的热电功率因子 (S(2)/ρ = 89 μW cm(-1) K(-2))，其中对热电势有贡献的主要机制是电子作为多数载流子的扩散热电产生。
