Thermal and electrical properties of Czochralski grown GeSi alloys

The thermoelectric parameters, the thermal conductivity, electrical conductivity and Seebeck coefficient were evaluated on high purity crystals of Ge_1-xSi_x alloys in the whole composition 0<x<1 at elevated temperatures up to 800°C. The thermal resistivity showed a maximum at x≈0.5 due to the phonon scattering. The electrical conductivity decreased with increasing x, relating to the intrinsic carrier concentration determined by the band gap energy at high temperatures. The Seebeck coefficient was extremely low in the composition 0.1<x<0.5 due to the small difference of the electron and hole mobilities. The large magnitude of the Seebeck coefficient was obtained in the GeSi with x=0.8 at elevated temperatures