Thermal conductivity of Si/SiGe superlattice nanowires

Abstract

The thermal conductivities of individual single crystalline Si/SiGe superlattice nanowires with diameters of 58 and 83 nm were measured over a temperature range from 20 to 320 K. The observed thermal conductivity shows similar temperature dependence as that of two-dimensional Si/SiGe superlattice films. Comparison with the thermal conductivity data of intrinsic Si nanowires suggests that alloy scattering of phonons in the Si–Ge segments is the dominant scattering mechanism in these superlattice nanowires. In addition, boundary scattering also contributes to thermal conductivity reduction.