Thermal conductivity of a single Bi₀.₅Sb₁.₅Te₃ single-crystalline nanowire.

Single-crystalline Bi₀.₅Sb₁.₅Te₃ nanowires were fabricated by a template-assisted pulsed electrodeposition technique; the thermal conductivity of a single Bi₀.₅Sb₁.₅Te₃ nanowire of different diameters was characterized through a self-heating 3 ω method. The temperature-dependent resistance measurements prove the semiconductor behavior of the nanowires. The extremely low thermal conductivity of the nanowires was found compared with the corresponding bulk, and the Umklapp peaks shift to a higher temperature as the decreasing nanowire's diameter decreases, which qualitatively agrees with the theoretical calculations based on the Callaway model. The boundary scattering plays an important role in the reduction of the thermal conductivity and in the shift of the Umklapp peak of the Bi₀.₅Sb₁.₅Te₃ nanowires.