Thermal conductivity of Si/SiGe superlattice nanowires

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. (C) 2003 American Institute of Physics.