The thermoelectric properties of Bi nanowires. Role of quantum size and surface effects.*

Because of the increased density of states arising from one-dimensional confinement, it is anticipated that bismuth quantum wires will exhibit superior thermoelectric properties. Recently, angle-resolved photoemission spectroscopy (ARPES) studies have shown that Bi supports surface states that have not been considered in current models of quantum confinement. Studies of the Fermi surface, employing the Shubnikov-de Haas (SdH) method, in arrays of 30- to 80-nm bismuth nanowires partially corroborates ARPES findings. Assuming diffusive conditions, the impact of the excess surface carriers on the thermopower is to effectively make it smaller than that of bulk Bi, in agreement with measurements reported in the literature. We will report the result of experiments designed to decrease the concentration of surface carriers..