Size-Dependent Transport and Thermoelectric Properties of Individual Polycrystalline Bismuth Nanowires

Thermoelectric materials convert a temperature difference into electricity and vice versa. Such materials utilize the Seebeck effect for power generation and the Peltier effect for cooling. In the Seebeck effect, a temperature difference across a material causes the diffusion of charged carriers across that gradient, thus creating a voltage difference between the hot and cold ends of the material. Conversely, the Peltier effect explains the fact that when current flows through a material a temperature gradient arises because the charged carriers exchange thermal energy. Thermoelectrics perform these functions without moving parts or toxic gases, which make them unique among power generation and cooling methods. Presently, thermoelectrics find only limited use because of their poor efficiency. The efficiency of a thermoelectric material is determined by the dimensionless figure of merit