理論計算を併用した擬ギャップ系・狭ギャップ系材料の熱電性能向上

抄録

This review briefly discusses the relationship between crystal structures, electronic structures, and thermoelectric properties of target materials. Examples include pseudogap quasicrystals and related approximant crystals, narrow-gap binary intermetallic compounds, and lead chalcogenides. The approach used is to identify the intrinsic physical properties from the experiment and establish a route for tuning their properties based on theoretical models and first-principles calculations. A possible route for improved thermoelectric performance is to use a band engineering approach, such as band convergence and introducing impurity states near the valence and conduction band edges. This approach was successfully applied to TiSi₂-type RuGa₂ and lead chalcogenides PbTe and PbSe.