Thermal conductivity measurement and analysis of Ge-SixGe1-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.