Thermopower Peculiarities of Uniaxial-Strained Bismuth Nanowires

We present the results of the investigations of the thermopower and electrical resistance of Pyrex-coated Bi nanowires. Here we show that there is a critical thickness of wire below which structural defects can strongly influence the charge transport in Bi nanowires, fabricated by the melt spinning method. At low temperature the contribution of holes to the thermopower dominates the electron contribution. Thermoelectric parameters of Bi nanowires may be controlled by applying a thermal treatment and/or a uniaxial pressure. A fairly high value of thermoelectric power factor was found under strain 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.