Improved Electrical Properties of n-Type SiGe Alloys

The effect of changes in the carrier concentration and mobility for heavily doped n-type SiGe on the electrical power factor has been investigated. It has been shown that power factors of 37-40 μV/cm-K² can be achieved with carrier concentrations of 2.0 - 2.5 × 1020 cm^-3 and mobilities of 38-40 cm²/V-sec. Many samples with suitable carrier concentration do not have high mobilities and some rationale for this behavior is presented.

Initial results are presented on fabrication of n-type samples from ultra-fine powders. The emphasis in this work is to achieve thermal conductivity reductions by adding inert particles to scatter mid-frequency phonons.