ICT2014 Abstracts

The power factor (=S²/ρ) expresses the upper limit on the amount of electrical power that can be drawn from a material. Therefore, it is important to have both a large Seebeck coefficient S and low electrical resistivity ρ to efficiently generate thermoelectricity. This is not easy to obtain, however, as a low ρ requires a high carrier density, while a large S will be associated with low carrier density. In this talk, we report on the enhanced power factor of doped PtAs₂ with a cubic pyrite-type structure. A large Seebeck coefficient was observed in the metallic state of Rh-doped PtAs₂; the Seebeck coefficient continued to increase up to 600 K, resulting in a large values of power factor (e.g. 65 μW/cmK²) over this range [1]. This value is larger than that of the typical thermoelectric material Bi₂Te₃ (40 μW/cmK²). We discuss that peculiarly shaped band structure, referred to as the "corrugated flat band" type, of PtAs₂ can result in large values of S in a metallic state of doped PtAs₂ [2].

[1] K. Kudo, S. Nakano, T. Mizukami, T. Takabatake, and M. Nohara, Appl. Phys. Lett. 103, 092107 (2013).

[2] K. Mori, H. Usui, H. Sakakibara, and K. Kuroki, AIP adv. 2, 042108 (2012).