Bismuth Nanowires for Potential Applications in Nanoscale Electronics Technology

Abstract Nanowires have potential applications in future generations of nanoscale electronics. Our motivation of studying Bi nanowires is based on the unique properties of bulk Bi. These include very small effective masses, a long mean-free path and the low melting point (271°C). Calculations of the transport properties predict that the Bi nanowires have a very high thermoelectric efficiency. The effects of quantum confinement are pronounced in Bi because of its small effective masses. The resulting change in the band structure of bulk Bi is shown in Fig. 1. The broken curves depict the band structure in which the T-point valence band overlaps with the L-point conduction band by 38mev making bulk Bi a semimetal. Due to quantum effects, the band edges split into subbands shown by solid curves. As the wire diameter decreases, eventually the lowest conduction subband and the highest valence subband no longer overlap and the material becomes an indirect-gap semiconductor (at ∼50nm diameter).