Power generation characteristics of thermoelectric conversion module using type-II (K,Ba)24(Ga,Sn)136 and type-VIII Ba8Ga16(Sn,Ge)30 clathrates

This thermoelectric (TE) module showed a conversion efficiency of 8.4% with a temperature difference of 300-700 K. This is superior to other modules at an operating temperature with a hot-side temperature of 500-700 K, where Bi2Te3 cannot be used. Its measured power generation characteristics were mostly similar to those simulated using the TE properties of the materials used. However, its measured electrical resistivity was ∼20% higher than the simulated one and the conversion efficiency was low. This is probably due to the presence of contact resistance between the materials and the electrodes of the module.