[19p-PA8-1~12] 9.4 Thermoelectric conversion

▲ [19p-PA8-4] High improvement of the figure of merit ZT in bulk amorphous-nanocrystalline Si_0.55Ge_0.35(Fe₁,P_0.10)

〇(DC)Kevin Delime¹, Muthusamy Omprakash¹, Ghodke Swapnil¹, Tsunehiro Takeuchi^1,2 (1.Toyota Tech. Inst., 2.Nagoya Univ.)

Keywords:SiGe, Amorphous, Nanostructure

The SiGe alloys are a cheap and non-toxic thermoelectric materials for high temperature applications. In order to improve its figure of merit , Omprakash et al. decreased the thermal conductivity of the amorphous-nanocrystallineSi_0.55Ge_0.35 with a stable value of thermal conductivity less than 1.35 W m^-1K^-1at T < 700 K. However, the ZT value wasn’t improved because of its low power factor. Takeuchi demonstrated that large transport properties can be obtained by the presence of two overlapping tight-bindings bands localized at the band edge of selected electrical band. By the use of calculations, we determined that Fe created some impurity states near the conduction band edge of SiGe, fitting well the precious cited conditions.
Therefore in this study, we investigated the thermoelectric properties of the Fe-doped bulk amorphous-nanocrystalline Si_0.55Ge_0.35(Fe₁,P_0.10), with P as electron carrier dopant.