The influence of phonon scatterings on the thermal conductivity of SiGe nanowires

The thermal conductivities of SiGe alloy nanowires with different Ge concentrations and diameters were measured at 60–450 K, and all the nanowires for the measurements were characterized by electron microscopies for accurately determining dimensions and atomic concentrations. With 37–63 at. % Ge concentrations and 44–60 nm diameters, their thermal conductivities approached to the minimum thermal conductivity of SiGe alloys due to strong phonon scatterings. This may suggest these parameters are sufficient to result in the smallest achievable thermal conductivity with SiGe in practice. A parallel resistor model was employed to investigate the influence of silicon oxide layers on their thermal conductivities.