Size-dependent thermal conductivity of individual single-crystalline PbTe nanowires

We investigated the thermal conductivity of individual single-crystalline PbTe nanowires grown by a chemical vapor transport method. Thermal conductivities of PbTe nanowires 182-436 nm in diameter were measured using suspended microdevices. The thermal conductivity of a PbTe nanowire appeared to decrease with decreasing nanowire diameter and was measured to be 1.29 W/mK for a 182 nm nanowire at 300 K, which is about half of that of bulk PbTe. Our results indicate that phonon transport through a PbTe nanowire is effectively suppressed by the enhanced phonon boundary scattering due to size effects.