Thermal and Thermoelectric Transport in Highly Resistive Single Sb 2 Se 3 Nanowires and Nanowire Bundles.

In this study, we measured the thermal conductivity and Seebeck coefficient of single Sb2 Se3 nanowires and nanowire bundles with a high resistivity (σ ~ 4.37 × 10-4 S/m). Microdevices consisting of two adjacent suspended silicon nitride membranes were fabricated to measure the thermal transport properties of the nanowires in vacuum. Single Sb2 Se3 nanowires with different diameters and nanowire bundles were carefully placed on the device to bridge the two membranes. The relationship of temperature difference on each heating/sensing suspension membranes with joule heating was accurately determined. A single Sb2 Se3 nanowire with a diameter of ~ 680 nm was found to have a thermal conductivity (kNW ) of 0.037 ± 0.002 W/m·K. The thermal conductivity of the nanowires is more than an order of magnitude lower than that of bulk materials (k ~ 0.36-1.9 W/m·K) and highly conductive (σ ~ 3 × 104 S/m) Sb2 Se3 single nanowires (k ~ 1 W/m·K). The measured Seebeck coefficient with a positive value of ~ 661 μV/K is comparable to that of highly conductive Sb2 Se3 single nanowires (~ 750 μV/K). The thermal transport between wires with different diameters and nanowire bundles was compared and discussed.