Thermal conductivity measurement and analysis of Ge-Si _x Ge_1−x core–shell nanowires

Abstract

We measured the thermal conductivity (κ) of two different Ge-SixGe1−x core–shell (CS) nanowires (NWs) with diameters of 40–50 nm and found to be 11.1 and 12.0 W m−1 K−1, respectively which were close to those of the Ge NW at 300 K. We also analyzed the measurement results using the modified Debye–Callaway model. Thermal analysis indicated that the decrease in the κ of the CS NWs resulted from dislocations at the CS interfaces, and predicted that the Ge NW has a rougher surface than the CS NWs because of oxygen protrusion through the oxidation front.