Submicron wires with nanosized grain structure

Recent results have shown that size-effects in nanostructured materials may enable much more efficient thermoelectric devices. In this paper, the electrochemical preparation of Bi1.95Te2.7Se0.35 and Bi2.15Te2.55Se0.3 submicron wires arrays with nanosized grain structure is reported. X-ray diffraction (XRD) analysis has indicated the presence of nanosized crystallites in the structure of the wires; high resolution transmission electron microscopy (HRTEM) investigations have confirmed the formation of crystallites with geometrical dimensions of 5–14 nm and random orientations in the structure of these wires. These wires were further analyzed by field emission scanning electron microscopy (FESEM). The measurement of the transport properties showed that a highly degenerate semiconductor with a large thermopower (−125 μV K−1 at 300 K) and a low resistivity was obtained.